® 281, 282, 284 40 MS/s Arbitrary Waveform Generators Users Manual January 2005 © 2005 Fluke Corporation, All rights reserved. Printed in USA All product names are trademarks of their respective companies.
LIMITED WARRANTY AND LIMITATION OF LIABILITY Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is one year and begins on the date of shipment. Parts, product repairs, and services are warranted for 90 days.
Safety This generator is a Safety Class I instrument according to IEC classification and has been designed to meet the requirements of EN61010-1 (Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use). It is an Installation Category II instrument intended for operation from a normal single phase supply. This instrument has been tested in accordance with EN61010-1 and has been supplied in a safe condition.
Note This instrument uses a Lithium button cell for non-volatile memory battery back-up. Typical battery life is 5 years. In the event of replacement becoming necessary, replace only with a cell of the correct type, a 3 V Li/Mn02 20 mm button cell type 2032. Do not mix with solid waste stream. Do not cut open, incinerate, expose to temperatures above 60 °C or attempt to recharge. Used batteries should be disposed of by a qualified recycler or hazardous materials handler.
EMC Compliance This instrument meets the requirements of the EMC Directive 89/336/EEC. Compliance was demonstrated by meeting the test limits of the following standards: Emissions EN61326 (1998) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use. Test limits used were: a) Radiated: Class B b) Conducted: Class B c) Harmonics: EN61000-3-2 (2000) Class A The instrument is Class A by product category.
b) after opening the case for any reason ensure that all signal and ground connections are remade correctly before replacing the cover. Always ensure all case screws are correctly refitted and tightened. c) In the event of part replacement becoming necessary, only use components of an identical type. Refer to the Service Manual.
Table of Contents Chapter 1 Title Page Introduction and Specifications......................................................... 1-1 Introduction........................................................................................................ Overview ....................................................................................................... Features ......................................................................................................... Specifications.................
281, 282, 284 Users Manual Inter-channel Triggering ........................................................................... 1-10 Interfaces ....................................................................................................... 1-10 General .......................................................................................................... 1-10 2 Installation ........................................................................................... 2-1 Mains Operating Voltage...
Contents (continued) Sweep Range ................................................................................................. Sweep Time ................................................................................................... Sweep Type ................................................................................................... Manual Sweep ............................................................................................... Sweep Spacing....................................
281, 282, 284 Users Manual Wave Invert ................................................................................................... Position Markers............................................................................................ Arbitrary Waveform Sequence .......................................................................... Sequence Set-up ............................................................................................
Contents (continued) Calibration ......................................................................................................... 14-5 Copying Channel Set-ups .................................................................................. 14-5 15 Calibration............................................................................................ 15-1 Introduction........................................................................................................ Equipment Required ......
281, 282, 284 Users Manual Cleaning ............................................................................................................. 17-2 Appendices A B C D E F G Mains Operating Voltage ............................................................................ Warning and Error Messages ...................................................................... SYNC OUT Automatic Settings ................................................................. Factory System Defaults .................
List of Tables Table 3-1. 7-1. 16-1. 1-1. Title Page RS232 Pin Functions.............................................................................................. Phase Range and Resolution - Triggered Burst Mode ........................................... Remote Command Summary ................................................................................. Approved Fuse Types ............................................................................................
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Chapter 1 Introduction and Specifications Introduction........................................................................................................ Overview ....................................................................................................... Features ......................................................................................................... Specifications.....................................................................................................
281, 282, 284 Users Manual Introduction Overview This manual describes the features and operation of the Fluke models 281, 282 and 284 single-, two- and four-channel arbitrary waveform generators. The physical differences between the two and four-channel generators are straightforward: the two-channel instrument has no set-up keys or output connections for channels three and four. The single-channel instrument has essentially the same keys but they are arranged quite differently to suit the half-rack case.
Introduction and Specifications Introduction 1 The supplied Windows™-based arbitrary waveform creation software gives access to more comprehensive features, allowing you to create waveforms from mathematical expressions, from combinations of other waveforms, freehand, or using a combination of all three techniques. Waveforms created in this way are downloaded via the RS232 or GPIB interface. Up to 100 waveforms may be stored, each with a user-specified length and name.
281, 282, 284 Users Manual Specifications Specifications apply at 18-28ºC after 30 minutes warm-up, at maximum output into 50 Ω Waveforms Standard Waveforms Sine, square, triangle, DC, positive ramp, negative ramp, sin(x)/x, pulse, pulse train, cosine, haversine and havercosine. Sine, Cosine, Haversine, Havercosine Range: 0·1 mHz to 16 MHz Resolution: 0·1 mHz or 7 digits Accuracy: 10 ppm for 1 year Temperature stability: Typically <1 ppm/ºC. Output level: 2.
Introduction and Specifications Specifications 1 Delay: range: -99·99 s to + 99·99 s resolution: 0·002 % of period or 25 ns, whichever is greater Width: range: 25 ns to 99·99 s resolution: 0·002 % of period or 25 ns, whichever is greater Note that the pulse width and absolute value of the delay may not exceed the pulse period at any time. Pulse trains of up to 10 pulses may be specified, each pulse having independently defined width, delay and level.
281, 282, 284 Users Manual Gated Waveform runs while the gate signal is true and stops while false. Carrier waveforms: Maximum carrier frequency: Trigger repetition rate: Gate signal source: Gate start/stop phase: All standard and arbitrary. The smaller of 1 MHz or the maximum for the selected waveform. 40 M samples/s for arb and Sequence. 0.005 Hz to 100 kHz internal DC to 1 MHz external. Internal from keyboard, previous channel, next channel or trigger generator.
Introduction and Specifications Specifications 1 Tone switching modes: gated: The tone is output while the trigger signal is true, and stopped at the end of the current waveform cycle, while the trigger signal is false. The next tone is output when the trigger signal is true again. triggered: The tone is output when the trigger signal goes true. The next tone is output, at the end of the current waveform cycle, when the trigger signal goes true again.
281, 282, 284 Users Manual Output signal level: TTL/CMOS logic levels from typically 50 Ω Cursor/Marker Out Adjustable output pulse for use as a marker in sweep mode or as a cursor in arbitrary waveform editing mode. Can be used to modulate the Z-axis of an oscilloscope or be displayed on a second oscilloscope channel. Output Signal Level: Output Impedance: Adjustable from nominally 2 to 14 V, normal or inverted; adjustable width as a cursor.
Introduction and Specifications Specifications 1 Inter-channel Operation Inter-channel Modulation The waveform from any channel may be used to amplitude modulate (AM) or suppressed carrier modulate (SCM) the next channel. Alternatively any number of channels may be modulated (AM or SCM) with the signal at the MODULATION input socket.
281, 282, 284 Users Manual The signals from the REF IN/OUT socket and the SYNC OUT socket can be used to phase lock two instruments where more than 4 channels are required. Inter-channel Triggering Any channel can be triggered by the previous or next channel. The previous/next connections can be used to "daisy chain" a trigger signal from a "start" channel, through a number of channels in the chain to an "end" channel.
Chapter 2 Installation Mains Operating Voltage................................................................................... Fuse.................................................................................................................... Mains Lead ........................................................................................................ Mounting............................................................................................................
281, 282, 284 Users Manual Mains Operating Voltage Check that the instrument operating voltage marked on the rear panel is correct for the local supply. If it is necessary to change the operating voltage, follow the procedure described in appendix A. Fuse Ensure that the correct mains fuse is fitted for the set operating voltage. The correct mains fuse types are listed in Appendix A. Mains Lead Warning To avoid the possibility of electric shock, this instrument must be earthed.
Chapter 3 Connections Introduction........................................................................................................ Front Panel Connections .................................................................................... MAIN OUT ................................................................................................... SYNC OUT ................................................................................................... TRIG IN .....................................
1, 282, 284 Users Manual Introduction This chapter describes the front- and rear-panel connections and their functions. Front Panel Connections MAIN OUT (1 per channel) MAIN OUT is the 50 Ω output from the channel’s main generator. It provides up to 20 V p-p into an open circuit or 10 V p-p into a matched 50 Ω load. It can tolerate a short circuit for 60 seconds. Caution To avoid risk of damage to the instrument, do not apply external voltages to these outputs.
Connections Rear Panel Connections 3 SYNC OUT logic levels are nominally 0 V and +5V from typically 50 Ω. SYNC OUT will withstand a short circuit. Caution To avoid risk of damage to the instrument, do not apply external voltages to this output. TRIG IN TRIG IN is the external input for trigger, gate, sweep and sequence operations. It is also the input used to synchronize the generator as a slave to another generator which is the master.
281, 282, 284 Users Manual As an output the logic levels are nominally 1 V and 4 V from typically 50 Ω. REF CLOCK IN/OUT will withstand a short-circuit. As an input the threshold is TTL/CMOS compatible. Caution To avoid risk of damage to the instrument, do not apply external voltages exceeding ±10 V to this socket. HOLD IN HOLD IN controls the waveform hold function. The input impedance is nominally 10 kΩ.
Connections Rear Panel Connections 3 Pin 2, 3 and 5 may be used as a conventional RS232 interface with XON/XOFF handshaking. Pins 7, 8 and 9 are used when the instrument is operated in addressable RS232 mode. Signal grounds are connected to the instrument ground. The RS232 address is set from the remote menu on the UTILITY screen, as described in chapter 14, System Operations from the Utility Menu.
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Chapter 4 Initial Operation Introduction........................................................................................................ Initial Operation................................................................................................. Switching On ................................................................................................. Display Contrast ............................................................................................ Keyboard ....................
281, 282, 284 Users Manual Introduction This section is a general introduction to the organization and principles of the instrument and is intended to be read before using the generator for the first time. Detailed operation is covered in later sections starting with chapter 5, Standard Waveform Operation. In this Users Manual front panel keys and sockets are shown in capitals, e.g. CREATE, SYNC OUT; all soft-key labels, entry fields and messages displayed on the LCD are shown in the Courier type-font, e.
Initial Operation Initial Operation • FREQuency, AMPLitude, OFFSET and MODE keys display screens which permit their respective parameters to be edited either from the numeric keypad or using the rotary control/cursor keys. • Numeric keys permit direct entry of a value for the parameter currently selected. Values are accepted in three formats: integer (20), floating point (20·0) and exponential (2 EXP 1).
281, 282, 284 Users Manual Note On multi-channel instruments the channel to be edited must first be selected by pressing the appropriate SETUP key; the lamp lights beside the SETUP key of the channel currently enabled for editing. A diamond beside a screen item indicates that it is selectable; hollow diamonds ( ) identify deselected items and filled diamonds ( ) denote selected items.
Initial Operation Principles of Operation 4 Thus for STANDARD FREQUENCY set to 1.000000 MHz rotating the control will change the frequency in 1 kHz steps. The display will auto-range up or down as the frequency is changed, provided that autoranging permits the increment size to be maintained; this will in turn determine the lowest or highest setting that can be achieved by turning the control.
281, 282, 284 Users Manual shb0006f.emf Figure 4-2. Clock Synthesis Mode DDS Mode In DDS mode all waveforms are stored in RAM as 4096 points. The frequency of the output waveform is determined by the rate at which the RAM addresses are changed. The address changes are generated as follows: The RAM contains the amplitude values of all the individual points of one cycle (360 º) of the waveform; each sequential address change corresponds to a phase increment of the waveform of 360/4096 degrees.
Chapter 5 Standard Waveform Operation Introduction........................................................................................................ Standard Waveform Operation .......................................................................... Setting Generator Parameters ............................................................................ Waveform Selection ...................................................................................... Frequency ...............................
281, 282, 284 Users Manual Introduction This section deals with the use of the instrument as a standard function generator, i.e. generating sine, square, triangle, dc, ramp, haversine, cosine, havercosine and sin(x)/x waveforms. All but the square wave are generated by DDS which gives 7-digit frequency precision; the square wave is generated by clock synthesis which results in only 4-digit frequency resolution. Refer to Principles of Operation in the previous chapter for an explanation of the differences.
Standard Waveform Operation Setting Generator Parameters 5 always show the entry in the most appropriate engineering units, in this case 12·34000 kHz. With period selected instead of freq the frequency can be set in terms of a period, for example 123·4µs can be entered as ·0001234 or 123·4 exp -6; again the display will always show the entry in the most appropriate engineering units.
281, 282, 284 Users Manual Alternate presses of the ± key will invert the signal at the MAIN OUT socket; if the DC OFFSET is non-zero the signal is inverted about the same offset. The exception to this occurs when the amplitude is specified in dBm. Since low level signals are specified in dBm (0 dBm = 1 mW into 50 Ω = 0.224 mV rms) the - sign is interpreted as part of a new amplitude entry and not as a command to invert the signal.
Standard Waveform Operation Warning and Error Messages 5 DC OFFSET: program +1.50 Vdc (actual +1.50 Vdc) load:hiZ If the amplitude is now reduced to, say, 250 mV pp, this introduces the attenuator and the actual dc offset changes by the appropriate factor: DC OFFSET: program +1.50 Vdc (actual +151 mVdc) load:hiZ The above display shows that the set DC offset is +1.50V but the actual offset is +151mV.
281, 282, 284 Users Manual choose to change the output level or the offset to produce a signal which is not clipped. The word (clip?) will show in the display beside AMPLITUDE or DC OFFSET while the clipped condition exists. ERROR messages are shown when an illegal setting is attempted, most generally a number outside the range of values permitted. In this case the entry is rejected and the parameter setting is left unchanged, as in the following three examples: 1.
Standard Waveform Operation SYNC Output burst done: Produces a pulse coincident with the last cycle of the burst. sequence sync: Produces a pulse coincident with the end of a waveform sequence. trigger: Selects the current trigger signal (internal, external, adjacent channel or manual). Useful for synchronizing burst or gated signals. sweep sync: Outputs the sweep trigger signal. phase lock: Used to lock two or more generators. Produces a positive edge at the 0 º phase point.
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Chapter 6 Sweep Operation Introduction........................................................................................................ Principles of Sweep Operation ...................................................................... Connections for Sweep Operation................................................................. Setting Sweep Parameters.................................................................................. Sweep Range ..................................................
281, 282, 284 Users Manual Introduction Principles of Sweep Operation All standard and arbitrary waveforms can be swept with the exception of pulse, pulsetrain and sequence. During sweep all waveforms are generated in DDS mode because this offers the significant advantage of phase-continuous sweeps over a very wide frequency range (up to 1010:1).
Sweep Operation Setting Sweep Parameters 6 Setting Sweep Parameters Pressing the SWEEP key (or the sweep setup… soft-key on the displays the SWEEP SETUP screen: MODE screen) SWEEP SETUP: off range… type… time… spacing… manual… marker… Menus for setting up the range, time (sweep rate), type (continuous, triggered, etc.) spacing (linear or logarithmic) and marker position are all accessed from this screen using the appropriate soft-key. In addition the control screen for manual sweep (i.e.
281, 282, 284 Users Manual Sweep Time Pressing the time… soft-key calls the SWEEP TIME screen: SWEEP TIME: 0.05 sec (steps=100) done The sweep time can be set from 0·03 to 999 s with 3-digit resolution by direct keyboard entry or by using the rotary control. As explained above, sweeps lasting less than 1·03 seconds will contain less than the maximum 2048 steps because of the minimum 0·5 ms dwell at each step.
Sweep Operation Setting Sweep Parameters 6 This is useful because it forces the sweep always to start from the same point in the waveform. You should be aware that in this case the waveform discontinuity may be undesirable in some circumstances, for example in filter evaluation. With sync is set to off the frequency steps directly and phase continuity is maintained from the stop frequency to the start frequency. Note, however, that the sweep is not synchronized to the software-generated trigger signal.
281, 282, 284 Users Manual Sweep Spacing Pressing the spacing… soft-key on the SWEEP SETUP screen calls the SWEEP SPACING screen: SWEEP SPACING: logarithmic linear done With linear selected the sweep changes the frequency at a linear rate; with logarithmic selected the sweep spends an equal time in each frequency decade. Sweep Marker Pressing the marker… soft-key on the SWEEP SETUP screen calls the SWEEP MARKER FREQ screen: SWEEP MARKER FREQ: MHz program: 5.000 actual: 4.
Chapter 7 Triggered Burst and Gate Introduction........................................................................................................ Internal Trigger Generator............................................................................. External Trigger Input ................................................................................... Adjacent Channel Trigger Output ................................................................. Triggered Burst .................................
281, 282, 284 Users Manual Introduction Triggered burst and gated modes are selected from the MODE screen, called by the MODE key, as alternatives to the default continuous mode. MODE: continuous gated triggered setup… setup… In triggered burst mode a defined number of cycles are generated following each trigger event. This mode is edge triggered. In gated mode the generator runs whenever the gating signal is true. This mode is level sensitive.
Triggered Burst and Gate Triggered Burst 7 External Trigger Input External trigger or gate signals are applied to the front panel TRIG IN socket which has a TTL level (+1·5 V) threshold. In triggered burst mode the input is edge sensitive; the selected edge of each external trigger initiates the specified burst. In gated mode the input is level sensitive; the output of the main generator is on whilst the gate signal is true.
281, 282, 284 Users Manual screen on which the burst count and start phase are set. The other trigger parameters are set on the TRIGGER IN set-up screen called by pressing the TRIG IN key. TRIGGER IN: force source: internal slope: positive period: 2.00ms Trigger Source The trigger source can be selected with the source soft-key on the TRIGGER IN set-up screen to be internal, external, manual or (in the case of multichannel instruments) either of the adjacent channels.
Triggered Burst and Gate Triggered Burst 7 The required count can be set by pressing the burst cnt soft-key followed by direct entries from the keyboard, or by using the rotary control. The maximum number of waveform cycles that can be counted is 1,048,575 (220-1). Start Phase The start phase, i.e. the point on the waveform cycle at which the burst starts, can be selected by pressing the phase soft-key followed by direct entries from the keyboard or by using the rotary control.
281, 282, 284 Users Manual channel’s TRIGGER IN screen. Select the channel to start the sequence with the appropriate SETUP key, select the TRIGGER IN screen with the TRIG IN key and press the force soft-key. Gated Mode Gated mode is turned on with the gated soft-key on the MODE screen. The setup… soft-key on this screen accesses the TRIGGER/GATE SETUP screen on which the start phase is set.
Triggered Burst and Gate Sync Out in Triggered Burst and Gated Mode 7 The start phase, i.e. the point on the waveform cycle at which the gated waveform starts, can be selected by pressing the phase soft-key followed by direct entries from the keyboard or by using the rotary control. Since the waveform cycle is always completed at the end of the gated period the start phase is also the stop phase. The phase can be set with a precision of 0.
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Chapter 8 Tone Mode Introduction........................................................................................................ Tone Frequency ................................................................................................. Tone Type .......................................................................................................... Tone Switching Source ......................................................................................
281, 282, 284 Users Manual Introduction In Tone mode the output is stepped through a user-defined list of up to 16 frequencies under the control of the signal set by the source soft-key on the TRIGGER IN set-up screen. This signal can be the internal trigger generator, an external trigger input, the front panel MAN TRIG key or a remote command. On multi-channel instruments the control signal can also be the trigger out from an adjacent channel.
Tone Mode Tone Switching Source 8 Thus the difference between triggered and gated tone changes is that in triggered mode the signal changes phase continuously from one frequency to the next at the waveform zero-crossing point immediately after the trigger signal, whereas in gated mode there can be an off (no signal) period between successive frequencies while the gate signal is not true.
281, 282, 284 Users Manual DTMF Testing with a Multi-Channel Generator An important use of tone mode is DTMF (Dual Tone Multiple Frequency) testing in which two channels are set up with equal length lists of different frequencies, triggered from a common signal. The outputs are summed together using the internal sum facility (see chapter 12, Sum). DTMF testing generally uses sine waves in the frequency range 600 Hz to 1.6 kHz.
Chapter 9 Arbitrary Waveform Generation Introduction........................................................................................................ Arb Waveform Terms ........................................................................................ Arb Waveform Creation and Modification – General Principles ...................... Selecting and Outputting Arbitrary Waveforms ................................................ Creating New Waveforms..............................................
281, 282, 284 Users Manual Introduction Arbitrary (arb) waveforms are generated by sequentially addressing the RAM containing the waveform data with the arbitrary clock. The frequency of the arb waveform is determined both by the arb clock and the total number of data points in the cycle. In this instrument an arb waveform can have up to 65,536 horizontal points. The vertical range is -2048 to +2047, corresponding to a maximum peak-peak output of 20 V.
Arbitrary Waveform Generation Selecting and Outputting Arbitrary Waveforms 9 2. Modifying that waveform using the various editing capabilities to get exactly the waveform required. These steps are fully described in the Creating New Waveforms and Modifying Arbitrary Waveforms sections which follow. Waveform creation using waveform design software also consists of two steps: 1. Creating the waveform using the software on a PC. 2. Downloading the waveform to the generator via the RS232 or GPIB interface.
281, 282, 284 Users Manual ARBS: wv00 wv01 wv02 backup mem 01024 03782 00500 The rotary control or cursor keys can be used to scroll the full list backwards and forwards through the display. With the appropriate channel selected using its SETUP key press the soft-key beside the required waveform to load it into that channel’s memory. Many waveforms can be loaded into and held in the channel’s memory in this way, up to the 64k point limit.
Arbitrary Waveform Generation Creating New Waveforms create: "wv00 size: 01024 cancel 9 " create The top line contains the user-defined waveform name which can be up to 8 characters long. The instrument allocates a default name of wv(n) starting at wv00; the name can be edited by selecting the appropriate character position with the cursor keys and then setting the character with the rotary control which scrolls through all alphanumeric characters in sequence.
281, 282, 284 Users Manual Modifying Arbitrary Waveforms Certain restrictions apply to waveform modification. They are summarized at the head of this chapter. Pressing the MODIFY front panel key, or the create soft-key on either of the CREATE NEW WAVEFORM menus calls the MODIFY screen: MODIFY: vwv01 resize… rename… delete… info… edit waveform This screen gives access to a number of menus which permit the selected waveform to be resized, renamed, edited, etc.
Arbitrary Waveform Generation Modifying Arbitrary Waveforms 9 Resize is implemented by pressing the resize soft-key. The cancel soft-key leaves the size unchanged. Both soft keys return the display to the MODIFY screen.
281, 282, 284 Users Manual Delete Waveform Pressing the delete… soft-key displays a request for confirmation that the selected waveform is to be deleted from the backup memory. Delete waveform "wv01 " ? cancel delete Confirm deletion by pressing the delete soft-key which will return the display to the MODIFY screen with the next arb waveform automatically selected; the cancel soft key aborts the deletion.
Arbitrary Waveform Generation Modifying Arbitrary Waveforms 9 waveform can be copied into itself (block copy) and position markers for use at SYNC OUT can also be defined. Pressing the exit soft-key on any of these edit screens will return the display to the EDIT FUNCTIONS menu.
281, 282, 284 Users Manual wv01 00000 strt 00512 stop exit wv02 00400 01000 insert Wave insert places waveforms between programmable start and stop points. Both standard and arbitrary waveforms can be inserted in the new waveform, with the exception of pulse, pulse-train and sequence. You can insert a section of an arbitrary waveform, defined by the left-hand strt (start) and stop addresses, for example points 00000 to 00512 of wv01 on the screen above.
Arbitrary Waveform Generation Modifying Arbitrary Waveforms 9 Block copy edit operates on the version of the waveform in the channel currently selected by the channel SETUP keys, and the effect of the edit can be seen by selecting the waveform to run on that channel. When your waveform is ready it can be saved by pressing the save soft-key; the action of saving modifies the waveform in the backup memory and also any other copies of the waveform in other channel memories.
281, 282, 284 Users Manual The waveform offset can be changed on a section of the waveform defined by the start and stop addresses. Set the addresses by pressing the appropriate soft-key and making entries directly from the keyboard or by using the rotary control. The data values over the specified section of the waveform are offset by the value entered in the WAVE OFFSET field. Press the appropriate soft-key and make entries directly from the keyboard or by using the rotary control.
Arbitrary Waveform Generation Arbitrary Waveform Sequence 9 Position markers can be set at any or all of the addresses of a waveform either individually, using the adrs (address) soft-key, or as a pattern, using the patterns… menu. A marker can be set directly at an address by pressing the adrs soft-key followed by a keyboard entry. Pressing the right-hand soft-key on the adrs line then toggles the marker setting between <1> and <0>.
281, 282, 284 Users Manual A previously defined sequence can be run and stopped from this screen using the run and stop soft-keys. The sequence can also be switched on from the STANDARD WAVEFORMS screen with the sequence soft-key. The segs= field shows the number of segments in the sequence; there is always at least 1 segment.
Arbitrary Waveform Generation Frequency and Amplitude Control with Arbitrary Waveforms 9 screen with the exception of the MAN TRIG key (which when pressed can only produce an edge, not a level). Providing the step on: field is set to count for all segments the waveform sequence can also be run in gated and triggered burst modes in the same way as simple waveforms. Refer to chapter 7, Triggered Burst and Gate for full details.
281, 282, 284 Users Manual Frequency or period can now only be set in terms of the clock frequency. Frequency and period entries are made directly from the numeric keypad or by using the rotary control in the usual way. Amplitude Pressing the AMPLitude key with an arbitrary waveform selected calls the AMPLITUDE screen: AMPLITUDE: +20·0 Vpp Vpp load:hiZ This differs from the AMPLITUDE screen for standard waveforms in that amplitude can now only be entered in volts peak-to-peak.
Arbitrary Waveform Generation Output Filter Setting 9 Pressing the front panel MAN HOLD key stops the waveform at the current level on all enabled channels; pressing MAN HOLD a second time restarts the waveform from that level. If the ARB HOLD INPUT screen is currently selected the status field will change from no hold to manual hold while the waveform is paused.
281, 282, 284 Users Manual The four filter choices, which are either automatically selected or set manually with the type soft-key, are as follows: 9-18 10 MHz elliptic: The automatic choice up to 10 MHz for sine, cosine, haversine, havercosine, sin(x)/x and triangle. Would be the better choice for arb waveforms with an essentially sinusoidal content. 16 MHz elliptic: The automatic choice above 10 MHz for sine, cosine, haversine and havercosine. Not recommended for any other waveforms.
Pulse and Pulse-trains Introduction 10 Chapter 10 Pulse and Pulse-trains Introduction........................................................................................................ Pulse Set-up ....................................................................................................... Pulse-Train Set-up ............................................................................................. Waveform Hold in Pulse and Pulse-Train Modes ............................................
281, 282, 284 Users Manual Introduction Pulse and pulse-trains are both selected and set-up from independent menus on the STANDARD WAVEFORMS screen called by pressing the STD key. Pulse and pulsetrains have similar timing set-ups and considerations but pulses are always unipolar, with a maximum amplitude of 10 V p-p, whereas pulse-trains can be bipolar, with a maximum amplitude of 20 V p-p. Pulse Set-up Pulse waveforms are turned on with the pulse soft-key on the STANDARD WAVEFORMS screen.
Pulse and Pulse-trains Pulse Set-up 10 The means by which pulse period is set-up in the hardware requires an understanding because it affects the setting resolution of both pulse width and delay. Pulse is actually a particular form of arbitrary waveform made up of between 4 and 50,000 points; each point has a minimum time of 25.00 ns corresponding to the fastest clock frequency of 40 MHz. At short pulse periods, i.e.
281, 282, 284 Users Manual Pulse-Train Set-up Pulse-trains are turned on with the pulse-train soft key on the STANDARD WAVEFORMS screen; pressing the setup… soft-key beside pulsetrain calls the first of the set-up screens: Enter no of pulses in train (1-10): 2 done next The number of screens used for the set-up depends on the number of pulses in the pulsetrain. The first three screens define the parameters that apply to the whole pattern (number of pulses, overall pulse-train period and baseline voltage).
Pulse and Pulse-trains Pulse-Train Set-up 10 The baseline is the signal level between the end of one pulse and the start of the next, i.e. it is the level at which all pulses start and finish. The baseline can be set between -5·0 V and +5·0 V by direct numeric keypad entries or by using the rotary control. Note that the actual baseline level at the output will only be as set in this field if the output amplitude is set to maximum (10 V p-p into 50 Ω) on the AMPLITUDE screen and terminated in 50 Ω.
281, 282, 284 Users Manual Pulse 1 delay program +0·000 ns (actual +0·000 ns) done next The pulse delay is entered in the same way as the pulse width and, again, the actual delay is shown below the program delay for the same reasons. The delay value that can be entered must be in the range ± (pulse-train period -1 point); positive values delay the pulse with respect to waveform sync from SYNC OUT; negative values cause the pulse to be output before the waveform sync.
Pulse and Pulse-trains Waveform Hold in Pulse and Pulse-Train Modes 10 ARB HOLD INPUT: status: no hold mode: disabled Each channel is selected in turn using the channel SETUP keys and set using the mode soft-key. The mode changes between disabled and enabled with alternate key presses. Pressing the front panel MAN HOLD key stops the waveform at the current level on all enabled channels; pressing MAN HOLD a second time restarts the waveform from that level.
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Chapter 11 Modulation Introduction........................................................................................................ External Modulation .......................................................................................... External VCA ................................................................................................ External SCM ................................................................................................ Internal Modulation .....................
281, 282, 284 Users Manual Introduction You can use both internal and external modulation sources. External modulation can be applied to any or all channels. Internal modulation uses the previous channel as the modulation source; for example channel 2 can be used to modulate channel 3. Clearly, internal modulation is not available on channel 1 or on a single channel instrument. The external modulation mode can be either VCA (voltage controlled amplitude) or SCM (suppressed carrier modulation).
Modulation Internal Modulation 11 The VCA signal is applied to the amplifier chain prior to the output attenuators. The amplifier itself is controlled over a limited range (approximately 10 dB); the full amplitude range of the channel is achieved by switching in up to five 10 dB attenuation stages. Peak modulation cannot exceed the maximum of the range within which the channel output has been set by choice of amplitude setting.
281, 282, 284 Users Manual The source soft-key steps the modulation choice between off, external and CHx where x is the number of the previous channel. With CHx selected the modulation can be switched between AM and SCM with alternate presses of the type soft-key. When AM is selected the screen has an additional soft-key labeled depth; selecting this key permits the modulation depth to be set directly from the keyboard or by the rotary control.
Chapter 12 Sum Introduction........................................................................................................ 12-2 External Sum...................................................................................................... 12-2 Internal Sum.......................................................................................................
281, 282, 284 Users Manual Introduction Both internal and external sum can be selected; summing can be used to add noise to a waveform, for example, or to add two signals for DTMF (dual tone multiple frequency) testing. External sum can be applied to any or all channels. Internal sum uses the previous channel as the source, so that for example channel 2 can be added into channel 3; internal sum is not available on channel 1 or on a single channel instrument.
Sum Internal Sum 12 possible to give a simple guide as to where the range breakpoints are because the use of dc offset, for example, changes these points. Within each range a SUM signal of approximately 2 V p-p will force the channel output from the range minimum to the range maximum; if the channel amplitude is set to midrange then the SUM signal needed to force the output to range maximum is halved to approximately 1 V p-p.
281, 282, 284 Users Manual The amplitude of the channel being used for the internal sum signal can still be adjusted on its own AMPLITUDE set-up screen; its status screen shows the message x to indicate that it is being used as a source for channel x. Internal sum cannot be used with internal modulation.
Chapter 13 Synchronization Introduction........................................................................................................ Inter-Channel Synchronization .......................................................................... Synchronizing Principles............................................................................... Master-Slave Allocation ................................................................................ Phase-setting between Channels......................
281, 282, 284 Users Manual Introduction Two or more channels in one multi-channel generator can be synchronized together and precise phase differences can be set between the channels. Two separate generators can also be synchronized, giving a maximum of 8 channels that can be operated synchronously.
Synchronization Inter-Channel Synchronization 13 master can be set. (More than one master can be selected but when locking is turned on with the status soft-key the set-up will be rejected.) Master/freq selects the master and sets frequency-tracking; for this to be operational the master and slave(s) must be set to the same frequency when locking is turned on. In this mode, when the frequency of the master is changed the frequency of the slaves also changes and the slaves are relocked to the master.
281, 282, 284 Users Manual mode: indep phase: +000.0º (actual: +000.0º status: off view Selecting the phase soft-key allows the phase to be set by direct keyboard entry or by rotary control. Setting the phase of a slave positive advances the waveform of the slave with respect to the master; setting it negative delays the slave with respect to the master. The phase of each slave channel can be set independently.
Synchronization Synchronizing Two Generators 13 3. Pulse and pulse train waveforms will lock to other pulse and pulse-trains (and to each other) but should be built with equal periods. 4. Arb waveforms should be the same length (although this requirement is not forced and violations do not create error messages). Synchronizing Two Generators This section covers the use of two generators to produce two or more synchronous signals.
281, 282, 284 Users Manual UTILITY screen. Refer to chapter 14, System Operations from the Utility Menu for additional information. REF CLOCK I/O SETUP input output phase lock slave Repeated presses of the phase lock soft-key toggle between master and slave. The slave is set to slave. Setting the slave generator to phase lock slave forces the slave’s mode to continuous and defaults all the SYNC OUT outputs to phase lock.
Synchronization Synchronizing Two Generators 13 Synchronizing Having made the connections and set up the generators as described in the preceding paragraphs, synchronization is achieved by pressing the MAN TRIG key of the slave. Once synchronized any change to the set-up will require resynchronization with the MAN TRIG key again.
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Chapter 14 System Operations from the Utility Menu Introduction........................................................................................................ Storing and Recalling Set-ups............................................................................ Channel Waveform Information ........................................................................ Warnings and Error messages............................................................................ Remote Interface Set-up ......
281, 282, 284 Users Manual Introduction Pressing the UTILITY key calls a list of menus which give access to various system operations including storing and recalling set-ups from non-volatile memory, error messages, power-on settings and calibration. Storing and Recalling Set-ups Complete waveform set-ups can be stored to or recalled from non-volatile RAM using the menus called by the store… and recall… soft-keys.
System Operations from the Utility Menu Warnings and Error messages 14 Warnings and Error messages The default set-up is for all warning and error messages to be displayed and for a beep to sound with each message. This set-up can be changed on the error… menu: error beep: ON error message: ON warn beep: ON warn message: ON Each feature can be turned ON or OFF with alternate presses of the appropriate softkey. The last two error messages can be viewed by pressing the last error… soft-key.
281, 282, 284 Users Manual CURSOR/MARKER OUTPUT amplitude: 2V polarity: negative cursor width: 1 The cursor/marker signal is output from the rear panel CURSOR/MARKER OUT socket. It is used as a marker in sweep mode or as a cursor in arbitrary waveform mode. It can be used to modulate the Z-axis of an oscilloscope or be displayed on a second oscilloscope channel. With amplitude selected the cursor/marker level can be set between 2 and 14 V in 2 V steps.
System Operations from the Utility Menu Calibration 14 Calibration Pressing the calibration soft key calls the calibration routine, described in chapter 15, Calibration. Copying Channel Set-ups An easy way of copying complete channel set-ups (waveform, frequency, amplitude, etc.) is accessed by pressing the COPY CHannel key: copy channel: 1 to channel: 2 execute The first line of the screen shows which channel is currently selected with the channel SETUP keys.
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Chapter 15 Calibration Introduction........................................................................................................ Equipment Required .......................................................................................... Calibration Procedure ........................................................................................ Setting the Password...................................................................................... Password Access to Calibration ...........
281, 282, 284 Users Manual Introduction All parameters can be calibrated without opening the instrument case; the generator offers ‘closed-box’ calibration. All adjustments are made digitally with calibration constants stored in EEPROM. The calibration routine requires only a digital voltmeter (DVM) and a frequency counter and takes no more than a few minutes. The crystal in the timebase is pre-aged but a further ageing of up to ±5 ppm can occur in the first year.
Calibration Calibration Routine 15 Enter a 4-digit password from the keyboard; the display will show the message NEW PASSWORD STORED! for two seconds and then revert to the UTILITY menu. If any keys other than 0-9 are pressed while entering the password the message ILLEGAL PASSWORD! will be shown. The password is held in EEPROM and will not be lost when the memory battery back-up is lost. In the event of the password being forgotten, contact the manufacturer for help in resetting the instrument.
281, 282, 284 Users Manual The full procedure is as follows: CAL CAL CAL CAL CAL CAL CAL CAL CAL 03 04 05 06 07 08 09 10 11 CH1 DC offset zero CH1 DC offset at + full scale CH1 DC offset at - full scale CH1 Multiplier zero CH1 Multiplier offset CH1 Waveform offset CH1 Output level at full-scale CH1 20 dB attenuator CH1 40 dB attenuator Adjust for 0 V ±5 mV Adjust for +10 V ±10 mV Check for -10 V ±3% Adjust for minimum voltage (AC) Adjust for 0 V ±5 mV Adjust for 0 V ±5 mV Adjust for 10 V ±10 mV Adjust f
Calibration Remote Calibration 15 CAL CAL CAL CAL 52 53 54 55 CH4 Sum offset CH4 SCM level at full-scale CH4 AM level at full-scale Clock calibrate Adjust for 0 V ±5 mV Adjust for 5 V ±5 mV Adjust for 10 V ±10 mV Adjust for 10·00000 MHz at SYNC OUT. Remote Calibration Calibration of the instrument may be performed over the RS232 or GPIB interface.
281, 282, 284 Users Manual For general information on remote operation and remote command formats, refer to chapter 16, Remote Operation.
Chapter 16 Remote Operation Introduction........................................................................................................ Address and Baud Rate Selection ...................................................................... Remote/Local Operation.................................................................................... RS232 Interface ................................................................................................. RS232 Interface Connector ................
281, 282, 284 Users Manual Introduction The instrument can be remotely controlled via its RS232 or GPIB interfaces. When using RS232 it can either be the only instrument connected to the controller or it can be part of an addressable RS232 system which permits up to 32 instruments to be addressed from one RS232 port. Some of the following sections are general and apply to all 3 modes (single instrument RS232, addressable RS232 and GPIB); others are clearly only relevant to a particular interface or mode.
Remote Operation RS232 Interface 16 RS232 Interface RS232 Interface Connector The 9-way D-type serial interface connector is located on the instrument rear panel. The pin connections are as shown in chapter 3, Connections, table 3-1. Single Instrument RS232 Connections For single instrument remote control only pins 2, 3 and 5 are connected to the PC. However, for correct operation links must be made in the connector at the PC end between pins 1, 4 and 6 and between pins 7 and 8, as shown below.
281, 282, 284 Users Manual The daisy chain consists of the transmit data (TXD), receive date (RXD) and signal ground lines only. There are no control/handshake lines. This makes XON/XOFF protocol essential and allows the inter-connection between instruments to contain just 3 wires.
Remote Operation RS232 Interface 16 blocks but all interface control codes are ignored. To return to addressable mode the instrument must be powered off. To enable addressable mode after an instrument has been powered on the Set Addressable Mode control code, 02H, must be sent. This will then enable all instruments connected to the addressable RS232 bus to respond to all interface control codes.
281, 282, 284 Users Manual Full List of Addressable RS232 Interface Control Codes 02H Set Addressable Mode. 03H Universal Unaddress control code. 04H Lock Non-Addressable mode control code. 06H Acknowledge that listen address received. 0AH Line Feed (LF); used as the universal command and response terminator. 0DH Carriage Return (CR); formatting code, otherwise ignored. 11H Restart transmission (XON). 12H Listen Address - must be followed by an address belonging to the required instrument.
Remote Operation Status Reporting 16 bit to be set in the Standard Event Status Register, a value of 2 to be placed in the Query Error Register and the response formatter to be reset thus clearing the output queue. The parser will then start parsing the next from the input queue. The section below on Status Reporting provides further information on these three error handling processes. GPIB Parallel Poll Complete parallel poll capabilities are offered on this generator.
281, 282, 284 Users Manual The Standard Event Status Register is read and cleared by the *ESR? command. The Standard Event Status Enable register is set by the *ESE command and read by the *ESE? command. Bit 7 Power On. Set when power is first applied to the instrument. Bit 6 Not used. Bit 5 Command Error. Set when a syntax type error is detected in a command from the bus. The parser is reset and parsing continues at the next byte in the input stream. Bit 4 Execution Error.
Remote Operation Power on Settings 16 shb0012f.gif Figure 16-4.
281, 282, 284 Users Manual Remote Commands RS232 Remote Command Formats Serial input to the instrument is buffered in a 256 byte input queue which is filled, under interrupt, in a manner transparent to all other instrument operations. The instrument will send XOFF when approximately 200 characters are in the queue. XON will be sent when approximately 100 free spaces become available in the queue after XOFF was sent. This queue contains raw (un-parsed) data which is parsed as it is required.
Remote Operation Remote Commands NL The new line character (0AH) NL^END The new line character with the END message ^END The END message with the last character of the message 16 Responses from the instrument to the controller are sent as . A consists of one followed by a . A is the new line character with the END message NL^END.
281, 282, 284 Users Manual SETUPCH Select channel as the destination for subsequent commands. The value of ranges from 1 to the highest channel number in the instrument. Frequency and Period These commands set the frequency or period of the generator main output and are equivalent to pressing the FREQ key and editing that screen. WAVFREQ Set the waveform frequency to Hz. WAVPER Set the waveform period to sec.
Remote Operation Remote Commands PULTRNWID , Set the width of pulse-train pulse number to sec. PULTRNDLY , Set the delay of pulse-train pulse number to sec. PULTRNMAKE Make the pulse-train and run it - similar to the WAVE PULSTRN command. ARB Select an arbitrary waveform for output. must be the name of an existing arbitrary waveform. Backup memory is always used as the source of the arb.
281, 282, 284 Users Manual character and the data ends with . If less data is sent than the number of points in the waveform the old data is retained from the point where the new data ends. If more data is sent the surplus is discarded. ARBDEF ,, Define a new or existing arbitrary waveform with name and length and load with the data in . If the arbitrary waveform does not exist it will be created.
Remote Operation Remote Commands ARBDATACSV , 16 Load data to an existing arbitrary waveform. must be the name of an existing arbitrary waveform. The data consists of ascii coded values, in the range --2048 to +2047, for each point. The values are separated by a comma character and the data ends with . The data is entered into the arbitrary waveform between the points specified by the ARBEDLMTS command.
281, 282, 284 Users Manual ARBDATA? Returns the data from an existing arbitrary waveform. must be the name of an existing arbitrary waveform. The data consists of binary coded values as specified for the ARBDATA command. The data is sent from the arbitrary waveform between the points specified by the ARBEDLMTS command. This command cannot be used over the RS232 interface since it contains a binary data block. ARBRESIZE , Change the size of arbitrary waveform to .
Remote Operation Remote Commands ARBAMPL ,, , Adjust the amplitude of arbitrary waveform in the address range to by the factor . ARBOFFSET ,, , Move the data in arbitrary waveform in the address range to by the offset . ARBINVERT ,, Invert arbitrary waveform in the address range to . ARBLEN? Returns the length, in points, of the arbitrary waveform .
281, 282, 284 Users Manual TONEEND Delete tone frequency number , thus defining the end of the list. TONEFREQ ,, Set tone frequency number to Hz. The third parameter sets the tone type; 1 will give trig, 2 will give FSK, any other value gives gate. SWPSTARTFRQ Set the sweep start frequency to Hz. SWPSTOPFRQ Set the sweep stop frequency to Hz. SWPCENTFRQ Set the sweep centre frequency to Hz.
Remote Operation Remote Commands FORCETRG Modulation Commands MOD Force a trigger to the selected channel. Will function with any trigger source except MANUAL specified. Set the modulation source to , or . MODTYPE Set the modulation type to or . AMDEPTH Set the depth for amplitude modulation to %. SCMLEVEL Set the level for SCM to Volts. SUM Set the sum source to , or .
281, 282, 284 Users Manual 16-20 *ESR? Returns the value in the Standard Event Status Register in numeric format. The register is then cleared. The syntax of the response is . *IDN? Returns the instrument identification. The exact response is determined by the instrument configuration and is of the form ,,0, where is the manufacturer’s name, defines the type of instrument and is the revision level of the software installed.
Remote Operation Remote Commands QER? Miscellaneous Commands *LRN? 16 Query and clear query the error number register. The response format is nr1. Returns the complete set-up of the instrument as a hexadecimal character data block. To reinstall the set-up the block should be returned to the instrument exactly as it is received. The syntax of the response is LRN . The settings in the instrument are not affected by execution of the *LRN? command.
281, 282, 284 Users Manual Remote Command Summary Table 16-1. Remote Command Summary 16-22 *CLS *ESE Clear status. *ESE? Returns the value in the Standard Event Status Enable Register in numeric format. *ESR? Returns the value in the Standard Event Status Register in numeric format. *IDN? *IST? Returns the instrument identification. *LRN? Returns the complete set up of the instrument as a hexadecimal character data block approximately 842 bytes long.
Remote Operation Remote Command Summary ABORT Aborts a phase locking operation. AMDEPTH Set the depth for amplitude modulation to %. AMPL Set the amplitude to in the units as specified by the AMPUNIT command. AMPUNIT Set the amplitude units to , or . ARB Select an arbitrary waveform for output.
281, 282, 284 Users Manual 16-24 ARBINSSTD ,, , Insert the standard waveform into the arbitrary waveform from start address to stop address . ARBINVERT ,, Invert arbitrary waveform between start address and stop address . ARBLEN? Returns the length, in points, of the arbitrary waveform .
Remote Operation Remote Command Summary LOCKMODE Set the channel lock mode to , , or . LOCKSTAT Set the channel lock status to or . LOCAL Returns the instrument to local operation and unlocks the keyboard. Will not function if LLO is in force. LRN Install data for a previous *LRN? command. MOD Set the modulation source to , or . MODE Set the mode to , , , or .
281, 282, 284 Users Manual 16-26 QER? Query and clear query error number register. REFCLK Set the ref. clock BNC connector to , , or . SCMLEVEL Set the level for SCM to Volts. SETUPCH Select channel SEQCNT , Set count for sequence segment to . SEQSEG , Set the status of sequence segment to or .
Remote Operation Remote Command Summary SYNCOUT Set the sync output , , , , , , , , or . TONEEND Delete tone frequency number thus defining the end of the list. TONEFREQ ,, Set tone frequency number to Hz. The third parameter sets the tone type; 1 will give trig, 2 will give FSK, any other value gives gate.
281, 282, 284 Users Manual 16-28
Chapter 17 Maintenance Introduction........................................................................................................ 17-2 Cleaning .............................................................................................................
281, 282, 284 Users Manual Introduction The manufacturers or their agents overseas will provide a repair service for any unit developing a fault. Where owners wish to undertake their own maintenance work, this should only be done by skilled personnel in conjunction with the service manual. Cleaning If the instrument requires cleaning use a cloth that is only lightly dampened with water or a mild detergent.
Appendices Appendix A B C D E F G Title Page Mains Operating Voltage .................................................................................... Warning and Error Messages .............................................................................. SYNC OUT Automatic Settings ......................................................................... Factory System Defaults ..................................................................................... Waveform Manager Plus...............
281, 282, 284 Users Manual -2
Appendix A Mains Operating Voltage Mains Operating Voltage Before connecting the instrument to an ac outlet, check that the instrument operating voltage marked on the rear panel is correct for the local supply. Warning To avoid the possibility of electric shock, always ensure the instrument is disconnected from the ac supply before opening the case. If it is necessary to change the operating voltage, proceed as follows: 1. Disconnect the instrument from all voltage sources. 2.
281, 282, 284 Users Manual Single Channel Model 281 shb0001f.emf Figure 1-1. Mains Transformer Connections - Model 281 for 230 V operation, connect the live (brown) wire to pin 15 for 115 V operation, connect the live (brown) wire to pin 14 for 100 V operation, connect the live (brown) wire to pin 13 Two- and Four-Channel Models 282 and 284 Figure 1-2.
Appendix B Warning and Error Messages Warning and Error Messages Warning messages are given when a setting may not give the expected result, e.g. DC Offset attenuated by the output attenuator when a small amplitude is set; the setting is, however, implemented. Error messages are given when an illegal setting is attempted; the previous setting is retained. The last two warning/error messages can be reviewed by selecting LAST ERROR from the UTILITY screen, the latest is reported first.
281, 282, 284 Users Manual 83 Numeric value too large - switching to sample period Error Messages 101 Frequency out of range for the selected waveform 102 Sample clock frequency required exceeds 40 MHz 103 Sample clock frequency required is less than 0.
Appendices Warning and Error Messages B 145 Selected mode is not available when phase lock master or slave 146 Cannot delete arbs while a sequence is running 147 Current set-up requires an arb wfm which does not exist 148 Trig/gate mode and seq step value cause a trigger conflict 149 Seq step value can't mix edge and level between segments 150 Number of pulses in train must be between 1 and 10 151 Pulse train base level must be >-5.0 V and <+5.0 V 152 Pulse level must be >-5.0 V and <+5.
281, 282, 284 Users Manual Remote Warnings 72 Length is different to that in the ARBDEF(CSV) command Remote Errors 120 Waveform limit value out of range 126 Illegal store number requested 162 Byte value outside the range 0 to 255 163 Specified arb name does not exist 164 Command illegal in sweep or tone mode 165 Cannot set waveform frequency or period for a sequence 166 Cannot set sample frequency or period for std waveforms 167 dBm output units assume a 50 Ohm termination 168 Specified units illegal for t
Appendix C SYNC OUT Automatic Settings SYNC OUT Automatic Settings The following automatic source (src) settings are made when selected on the SYNC OUTPUT SETUP screen. MODE Continuous Waveform Position WAVEFORM Sync Marker Standard 9 Arbitrary 9 Sequence Gate/Trig All Sweep All Tone All Ext.
281, 282, 284 Users Manual C-2
Appendix D Factory System Defaults Factory System Defaults The factory system defaults are listed in full below. They can be recalled by pressing RECALL followed by set defaults or by the remote command *RST. All channels will be receive the same set-up. All channels default to the same settings. Main Parameters Std.
281, 282, 284 Users Manual Spacing: Sweep Time: Type: Log 50 ms Continuous Sequence All segments set as follows: Status: Wfm: Step ON Count: Arbitrary Off except segment 1 First arb Count 1 All unaffected by reset or *RST Filter Sync Out Auto Auto Other D-2
Appendix E Waveform Manager Plus Arbitrary Waveform Creation and Management Software The Waveform Manager Plus program allows construction, editing, exchange, translation and storage of many types of waveform data. It is compatible with many popular DSOs and waveform generation products. Waveforms may be generated by equation entry, freehand drawing, combining existing waveforms or any combinations of these methods.
281, 282, 284 Users Manual Waveform Manager allows you to keep waveforms for different projects separate from each other on your hard drive. A project may be placed anywhere, in any directory (folder) and all waveform files for that project will be stored in a structure below that directory. A project is identified by a user defined name. Each project maintains its own library of expressions.
Appendix F Block Diagrams Block Diagrams Internal trigger generator TRIG IN front panel BNC Trigger out from Ch(n -1) Trigger out from Ch(n+1) Waveform end marker Trig in TRIGGERING Position Sequence end Burst done Manual / remote trigger Master clock in/out Modulation in front panel BNC Ch(n) carrier Sum in front panel BNC Mod/sum out from Ch(n-1) Lock out, routed via SYNC OUT BNC, if this instrument is the master PHASE LOCKING Internal lock in from this instrument Trigger out to Ch(n-1) and Ch(
281, 282, 284 Users Manual Internal lock in Manual/remote trigger Internal trigger gen TRIG IN BNC SUM IN BNC MODULATION IN BNC Master clock I I I I I I Channel 1 I/O I I I OO N/C I I I I I I Channel 2 I/O Ch1 mod/sum out I I I OO I I I I I I Channel 3 I/O I I I OO Ch2 mod/sum out I I I I I I Channel 4 I/O I I I OO Ch3 mod/sum out Trig out Ch 1 N/C Trig out Ch 2 Trig out Ch 3 Trig out Ch 4 shb0017f.emf Figure 6-2.
Appendix G Front and Rear Panel Drawings Front Panel: Single-Channel Model 281 shb0013f.gif Figure 7-1.
281, 282, 284 Users Manual Front Panel: 2-Channel Model 282 shb0014f.gif Figure 7-2. Front Panel - Model 282 Front Panel: 4-Channel Model 284 shb0015f.gif Figure 7-3.
Appendices Front and Rear Panel Drawings G Rear Panel: Single-Channel Model 281 shb0018f.gif Figure 7-4. Rear Panel - Model 281 Rear Panel: 2- and 4-Channel Models 282 and 284 shb0019f.gif Figure 7-5.
281, 282, 284 Users Manual G-4
Index —A— adding waveforms, 12-2 address remote, 16-2, 16-3 amplitude modulation, 11-2 arb, 9-2 arbitrary waveform, 9-2 —B— burst count, 7-4 —C— calibration, 14-5, 15-2 remote, 15-5 cleaning, 17-2 clipping, 11-3, 12-2 clock synthesis, 4-5 commands remote, 16-10 connections daisy-chain, 16-4 front panel, 3-2 rear panel, 3-3 RS232, 3-4 sweep, 6-2 synchronization, 13-5 creating arbitrary waveform, 9-2 —D— daisy-chain, 16-3 data entry, 4-3 DC offset, 9-11 direct digital synthesis, 4-5, 4-6 display, 4-2 draw
clock, 1-8, 3-3 ext sum, 12-2 hold, 1-8, 3-4, 10-7 modulation, 1-8, 3-3, 11-3 ref clock, 14-3 sum, 1-8, 3-3 trig, 1-8, 3-3 trig in, 11-3 inter-channel modulation, 1-9 operation, 1-9 phase locking, 1-9 summing, 1-9 triggering, 1-10 interfaces, 1-10 —K— key ampl, 4-3 copy ch, 4-3, 14-5 data entry, 4-3 freq, 4-3 inter ch, 4-3 local, 16-2 man hold, 4-3, 10-7 man trig, 4-3, 7-4, 13-7 mode, 4-3 modulation, 4-3 numeric, 4-3 offset, 4-3 recall, D-1 setup, 4-2, 4-3 status, 4-2, 4-3 sum, 4-3 sweep, 4-3, 6-3 sync out
Index (continued) INTER-CH, 13-2 MANUAL SWEEP FREQ, 6-5 MODE, 7-2 MODULATION, 11-2 POSITION MARKER, 9-12 POWER ON SETTING, 14-4 PULSE, 10-2 PULSE TRAIN, 10-4 REF CLOCK I/O, 13-6 REMOTE, 16-2 SEQUENCE, 9-13 STANDARD FREQUENCY, 5-2 STANDARD WAVEFORMS, 5-2 SUM, 12-2, 12-3 SWEEP MARKER FREQ, 6-6 SWEEP RANGE, 6-3 SWEEP SETUP, 6-3 SWEEP SPACING, 6-6 SWEEP TIME, 6-4 SWEEP TYPE, 6-4 SYNC OUT, 5-7 TONE, 8-2 TRIGGER IN, 7-2, 7-4, 7-6 TRIGGER OUT, 7-3 TRIGGER/GATE SETUP, 7-4, 7-6 WAVE OFFSET, 9-11 settings automatic
4
® 291, 292, 294 100 MS/s Arbitrary Waveform Generators Users Manual March 2006 © 2006 Fluke Corporation, All rights reserved. Printed in USA All product names are trademarks of their respective companies.
LIMITED WARRANTY AND LIMITATION OF LIABILITY Each Fluke product is warranted to be free from defects in material and workmanship under normal use and service. The warranty period is one year and begins on the date of shipment. Parts, product repairs, and services are warranted for 90 days.
Safety This generator is a Safety Class I instrument according to IEC classification and has been designed to meet the requirements of EN61010-1:2001 (Safety Requirements for Electrical Equipment for Measurement, Control and Laboratory Use). It is an Installation Category II instrument intended for operation from a normal single phase supply. This instrument has been tested in accordance with EN61010-1, CSA 22.2 No. 61010-104 and UL 61010A-1 and has been supplied in a safe condition.
Note This instrument uses a Lithium button cell for non-volatile memory battery back-up. Typical battery life is 5 years. In the event of replacement becoming necessary, replace only with a cell of the correct type, a 3 V Li/Mn02 20 mm button cell type 2032. Do not mix with solid waste stream. Do not cut open, incinerate, expose to temperatures above 60 °C or attempt to recharge. Used batteries should be disposed of by a qualified recycler or hazardous materials handler.
EMC Compliance This instrument meets the requirements of the EMC Directive 89/336/EEC. Compliance was demonstrated by meeting the test limits of the following standards: Emissions EN61326 (1998) EMC product standard for Electrical Equipment for Measurement, Control and Laboratory Use. Test limits used were: a) Radiated: Class A b) Conducted: Class B c) Harmonics: EN61000-3-2 (2000) Class A; the instrument is Class A by product category.
b) after opening the case for any reason ensure that all signal and ground connections are remade correctly before replacing the cover. Always ensure all case screws are correctly refitted and tightened. c) In the event of part replacement becoming necessary, only use components of an identical type, see the Service Manual.
Table of Contents Chapter Title Page Safety.................................................................................................... i EMC Compliance .............................................................................................. iii Emissions....................................................................................................... iii Immunity .......................................................................................................
291, 292, 294 Users Manual Inter-Channel Modulation:........................................................................ Inter-Channel Analog Summing: .............................................................. Inter-Channel Synchronization: ................................................................ Inter-Channel Triggering: ......................................................................... Interfaces ......................................................................................
Contents (continued) 6 Sweep Operation ................................................................................. 6-1 General............................................................................................................... Principles of Sweep Operation ...................................................................... Connections for Sweep Operation................................................................. Setting sweep parameters............................................
291, 292, 294 Users Manual Block Copy ............................................................................................... Waveform Amplitude................................................................................ Waveform Offset....................................................................................... Wave Invert............................................................................................... Position Markers ...................................................
Contents (continued) 15 System Operations from the Utility Menu ......................................... 15-1 Introduction........................................................................................................ Channel Waveform Information ........................................................................ Warnings and Error Messages ........................................................................... Remote Interface Set-Up.....................................................
291, 292, 294 Users Manual Modulation Commands............................................................................. Synchronizing Commands ........................................................................ Status Commands...................................................................................... Miscellaneous Commands ........................................................................ Remote Command Summary.......................................................................
Chapter 1 Introduction and Specifications Title Introduction........................................................................................................ Specifications..................................................................................................... Waveforms .................................................................................................... Standard Waveforms.................................................................................
291, 292, 294 Users Manual Introduction This range of synthesized programmable arbitrary waveform generators have the following features: • 1, 2 or 4 independent arb channels • Additional DC to 50MHz fixed amplitude sine and squarewave outputs on 2- and 4-channel instruments • Up to 100 MHz sampling frequency • Sinewaves up to 40 MHz, squarewaves up to 50 MHz • Output level 2.
Introduction and Specifications Introduction 1 All waveforms can be swept over their full frequency range at a rate variable between 1 millisecond and 15 minutes. Sweep can be linear or logarithmic, single or continuous. Single sweeps can be triggered from the front panel, the trigger input, or the digital interfaces. A sweep marker is provided. Amplitude modulation is available for all waveforms and is controlled from the previous channel or from an external generator via the MODULATION input socket.
291, 292, 294 Users Manual Specifications Specifications apply at 18 to 28 ºC after 30 minutes warm-up, at maximum output into 50 Ω. Waveforms Standard Waveforms Sine, square, triangle, DC, positive ramp, negative ramp, sin(x)/x, pulse, pulse train, cosine, haversine and havercosine. Sine, Cosine, Haversine, Havercosine Range: Resolution: Accuracy: Temperature stability: Output level: Harmonic distortion: Non-harmonic spurious: 0·1 mHz to 40 MHz 0·1 mHz or 10 digits 10 ppm for 1 year Typically <1 ppm/ºC.
Introduction and Specifications Specifications 1 Pulse and Pulse Train Output level: Rise and fall times: Period: range: resolution: accuracy: Delay: range: resolution: Width: range: resolution: 2.
291, 292, 294 Users Manual Operating modes Triggered Burst Each active edge of the trigger signal will produce one burst of the waveform. Carrier waveforms: Maximum carrier frequency: Number of cycles: Trigger repetition rate: Trigger signal source: Trigger start/stop phase: All standard and arbitrary The smaller of 2.5 MHz or the maximum for the selected waveform. 100 Msamples/s for arb or sequence. 1 to 1,048,575 0.005 Hz to 100 kHz internal, dc to 1 MHz external.
Introduction and Specifications Specifications Multi channel sweep 1 Any number of channels may be swept simultaneously with independent sweep parameters for each channel. Amplitude, Offset and Waveform can be set independently for each channel. Tone Switching Capability provided for both standard and arbitrary waveforms. Arbitrary waveforms are expanded or condensed to exactly 4096 points and DDS techniques are used to allow instantaneous frequency switching.
291, 292, 294 Users Manual Resolution: Sync Output 3 digits or 1 mV for both amplitude and dc offset. - one for each channel Multifunction output user definable or automatically selected to be any of the following: Waveform sync (all waveforms): Position markers (arbitrary only): Burst done: Sequence sync: Trigger: Sweep sync: Phase lock out: Output signal level: A square wave with 50 % duty cycle at the main waveform frequency, or a pulse coincident with the first few points of an arbitrary waveform.
Introduction and Specifications Specifications Input impedance: Typically 1 kΩ. Frequency range: DC to 30 MHz (25 MHz on 2- and 4-channel instruments) Approximately 2 V p-p input for 20 V p-p output; maximum input ±10 V. Typically 1 kΩ. 1 Sum In Signal range: Input impedance: Hold Holds an arbitrary waveform at its current position.
291, 292, 294 Users Manual Modulation source: Frequency range: Internal AM: depth: resolution: Carrier suppression (SCM): External modulation signal range: VCA: SCM: Internal from the previous channel; external from modulation input socket. The external modulation signal may be applied to any number of channels simultaneously. DC to >100 kHz. 0 % to 105 % 1 %. >40 dB. Approximately 1 V p-p for 100 % level change at maximum output. Approximately ±1 V pk for maximum output.
Introduction and Specifications Specifications 1 The previous/next connections can be used to daisy chain a trigger signal from a start channel, through a number of channels in the chain to an end channel. Each channel receives the trigger out signal from the previous (or next) channel, and drives its selected trigger out to the next (or previous) channel. The end channel trigger out can be set up to drive the start channel, thus closing the loop.
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Chapter 2 Installation Title AC Supply Voltage............................................................................................ Fuse ............................................................................................................... AC Supply Cable........................................................................................... Mounting............................................................................................................ Ventilation ..................
291, 292, 294 Users Manual AC Supply Voltage Check that the instrument operating voltage marked on the rear panel is correct for the local supply. If it is necessary to change the operating voltage, follow the procedure described in Appendix A. Fuse Ensure that the correct mains fuse is fitted for the set operating voltage. The correct mains fuse types are listed in Appendix A, together with instructions for fuse replacement.
Chapter 3 Connections Title Front panel connections ..................................................................................... MAIN OUT ................................................................................................... SYNC OUT ................................................................................................... TRIG IN ........................................................................................................ SUM IN ..................................
291, 292, 294 Users Manual Front panel connections MAIN OUT (1 per channel) MAIN OUT is the 50 Ω output from the channel's main generator. It will provide up to 20 V p-p into an open circuit or 10 V p-p into a matched 50 Ω load. It can tolerate a short circuit for 60 seconds. Caution Do not apply an external voltage to this output. SYNC OUT (1 per channel) SYNC OUT is a TTL/CMOS level output which may be set to any of the following signals from the SYNC OUT screen.
Connections Rear Panel Connections 3 TRIG IN This is the external input for trigger, gate, sweep and sequence operations. It is also the input used to synchronize the generator as a slave to another generator which is the master. Caution Do not apply an external voltage exceeding ±10 V. SUM IN This is the input socket for external signal summing. The channel(s) with which this signal is to be summed are selected on the SUM screen. Caution Do not apply an external voltage exceeding ±10 V.
291, 292, 294 Users Manual Caution Do not apply an external voltage exceeding ±10 V. ARB CLOCK IN/OUT Set to an input, this is the input for a user-supplied ARB clock in the frequency range dc to 50 MHz. Set to an output, it outputs the system clock at TTL/CMOS compatible logic levels. Caution Do not apply an external voltage exceeding + 5 V or –1 V.
Connections Rear Panel Connections 3 GPIB (IEEE-488) The GPIB interface is not isolated; the GPIB signal grounds are connected to the instrument ground. The implemented subsets are: SH1, AH1, T6, TE0, L4, LE0, SR1, RL1, PP1, DC1, DT1, C0, E2. The GPIB address is set from the remote menu on the UTILITY screen; see "System Operations from the Utility Menu". USB The USB port is connected to instrument ground. It accepts a standard USB cable.
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Chapter 4 Initial Operation Title Page Introduction........................................................................................................ Initial Operation................................................................................................. Switching On ................................................................................................. Display Contrast ............................................................................................ Keyboard .......
291, 292, 294 Users Manual Introduction This section is a general introduction to the organization and principles of the instrument and is intended to be read before using the generator for the first time. Detailed operation is covered in later sections starting with "Standard Waveform Operation". In this Users Manual front panel keys and sockets are shown in capitals, e.g. CREATE, SYNC OUT; all soft-key labels, entry fields and messages displayed on the LCD are shown in the Courier type-font, e.g.
Initial Operation Principles of Editing • FREQuency, AMPLitude, OFFSET and MODE keys display screens which permit their respective parameters to be edited either from the numeric keypad or using the rotary control/cursor keys. • Numeric keys permit direct entry of a value for the parameter currently selected. Values are accepted in three formats: integer (20), floating point (20·0) and exponential (2 EXP 1).
291, 292, 294 Users Manual Note On multi-channel instruments the channel to be edited must first be selected by pressing the appropriate SETUP key; the lamp lights beside the SETUP key of the channel currently enabled for editing. A diamond beside a screen item indicates that it is selectable; hollow diamonds ( ) identify deselected items and filled diamonds ( ) denote selected items.
Initial Operation Principles of Operation 4 Thus for STANDARD FREQUENCY set to 1.000000000 MHz rotating the control will change the frequency in 1 kHz steps. The display will autorange up or down as the frequency is changed, provided that autoranging permits the increment size to be maintained; this will in turn determine the lowest or highest setting that can be achieved by turning the control.
291, 292, 294 Users Manual Arbitrary waveforms have a user defined length of 8 to 1,048,576 points. Square waves use a fixed length of 2 points and pulse and pulse train have their length defined by the user selected period value. DDS Mode In DDS mode all waveforms are stored in RAM as 4096 points. The frequency of the output waveform is determined by the rate at which the RAM addresses are changed.
Chapter 5 Standard Waveforms Title Introduction........................................................................................................ Standard Waveform Operation .......................................................................... Setting Generator Parameters ............................................................................ Waveform Selection ...................................................................................... Frequency .................................
291, 292, 294 Users Manual Introduction This section deals with the use of the instrument as a standard function generator, i.e. generating sine, square, triangle, dc, ramp, haversine, cosine, havercosine and sin(x)/x waveforms. All but the square wave are generated by DDS which gives 10-digit frequency resolution; the square wave is generated by clock synthesis which results in only 8-digit frequency resolution. Refer to Principles of Operation in chapter 4 for an explanation of the differences.
Standard Waveforms Setting Generator Parameters 5 entered as 12340, 12340·00, or 1·234 exp 4 etc. However, the display will always show the entry in the most appropriate engineering units, in this case 12·34000000 kHz. With period selected instead of freq the frequency can be set in terms of a period, for example 123·4 µs can be entered as·0001234 or 123·4 exp -6; again the display will always show the entry in the most appropriate engineering units.
291, 292, 294 Users Manual DC Offset Pressing the OFFSET key gives the DC OFFSET screen: DC OFFSET: program +0.00 mVdc (actual +0.00 mVdc) load:hiZ The offset can be entered directly from the keyboard in integer, floating point or exponential format, for example 100 mV can be entered as 0.001 or as 100 exp -3, etc. The display will always show the entry in the most appropriate engineering units, in this case 100 mV.
Standard Waveforms Warning and Error Messages 5 DC OFFSET: program +1.50 Vdc (actual +151 mVdc) load: hiZ The above display shows that the set dc offset is +1.50 V but the actual offset is +151 mV. Note The actual offset value also takes into account the true attenuation provided by the fixed attenuator, using the values determined during the calibration procedure.
291, 292, 294 Users Manual 2. Entering an amplitude of 25 V p-p. The error message: Maximum output level exceeded is shown. 3. Entering a dc offset of 20 V. The error message: Maximum DC offset exceeded is shown. The messages remain on the display for approximately two seconds. The last two messages can be viewed again by pressing the last error… soft-key on the UTILITY screen. Refer to the section System Operations from the Utility Screen for more information.
Standard Waveforms Synchronization Output 5 SYNC OUT output: on mode: auto src: waveform sync SYNC OUT is turned on and off by alternate presses of the output soft-key. The selection of the signal to be output from the SYNC OUT socket is made using the src (source) soft-key; repeated presses of src cycle the selection through all the choices (waveform sync, position marker, etc.) listed above.
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Chapter 6 Sweep Operation Title General............................................................................................................... Principles of Sweep Operation ...................................................................... Connections for Sweep Operation................................................................. Setting sweep parameters................................................................................... Sweep Range .........................................
291, 292, 294 Users Manual General Principles of Sweep Operation All standard and arbitrary waveforms can be swept with the exception of pulse, pulsetrain and sequence. During sweep all waveforms are generated in DDS mode because this offers the significant advantage of phase-continuous sweeps over a very wide frequency range (up to 1010:1).
Sweep Operation Setting sweep parameters 6 Menus for setting up the range, time (sweep rate), type (continuous, triggered, etc.) spacing (lin/log) and marker position are all accessed from this screen using the appropriate soft key. Sweep mode itself is turned on and off with alternate presses of the on/off soft key; sweep can also be turned on by the sweep soft key on the MODE screen. On multi-channel instruments two or more channels can be swept at once.
291, 292, 294 Users Manual Sweep Type Pressing the type… soft key calls the SWEEP TYPE screen. SWEEP TYPE: continuous direction: up sync: on done This screen is used to set the sweep mode (continuous; triggered; trig'd, hold/reset) and the sweep direction. Successive presses of the direction soft key select one of the following sweep directions: up down up/down down/up start frequency to stop frequency. stop frequency to start frequency. start frequency to stop frequency and back to start frequency.
Sweep Operation Setting sweep parameters 6 Sweep Spacing Pressing the spacing… soft key on the SWEEP SETUP screen calls the SWEEP SPACING screen. SWEEP SPACING: logarithmic linear done With linear selected the sweep changes the frequency at a linear rate; with logarithmic selected the sweep spends an equal time in each frequency decade. Sweep Marker A sweep marker pulse is also available from the SYNC OUT socket when sweep sync (the default condition) is selected.
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Chapter 7 Triggered Burst and Gate Title Page General............................................................................................................... Internal Trigger Generator............................................................................. External Trigger Input ................................................................................... Adjacent Channel Trigger Output ................................................................. Triggered Burst ..................
291, 292, 294 Users Manual General Triggered burst and gated modes are selected from the MODE screen, called by the MODE key, as alternatives to the default continuous mode. MODE: continuous gated triggered off setup… setup… In triggered burst mode a defined number of cycles are generated following each trigger event. This mode is edge triggered. In gated mode the generator runs whenever the gating signal is true. This mode is level sensitive.
Triggered Burst and Gate Triggered Burst 7 to +5·0 V by direct keyboard entry or by using the rotary control. In triggered burst mode the input is edge sensitive; the selected edge of each external trigger initiates the specified burst. In gated mode the input is level sensitive; the output of the main generator is on whilst the gate signal is true. The minimum pulse width that can be used with TRIG IN in triggered burst and gated modes is 50 ns and the maximum repetition rate is 1 MHz.
291, 292, 294 Users Manual screen on which the burst count and start phase are set. The other trigger parameters are set on the TRIGGER IN set-up screen called by pressing the TRIG IN key. source: slope: level: period: int force positive +1.4 V 1.00ms Trigger Source The trigger source can be selected with the source soft key on the TRIGGER IN set-up screen to be int, ext, man or an adjacent channel.
Triggered Burst and Gate Triggered Burst 7 Start Phase The start phase, i.e. the point on the waveform cycle at which the burst starts, can be selected by pressing the phase soft key followed by direct entries from the keyboard or by using the rotary control. Since the waveform cycle is always completed at the end of the burst the start phase is also the stop phase.
291, 292, 294 Users Manual Gated mode Gated mode is turned on with the gated soft key on the MODE screen. The setup... soft key on this screen accesses the TRIGGER/GATE SETUP screen on which the start phase is set. The other parameters associated with gated mode are set on the TRIGGER IN set-up screen called by pressing the TRIG IN key. source: slope: level: period: int force positive +1.4 V 1.
Triggered Burst and Gate Sync Out in Triggered Burst and Gated Modes 7 The phase can be set with a precision of 0·1 ° but the actual resolution is limited with some waveforms and at certain waveform frequencies as detailed below. To indicate when this is the case the actual phase is shown in brackets as a non-editable field below the programmed value. To achieve start phase precision all waveforms are run in clock synthesis mode, i.e.
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Chapter 8 Tone Mode Title Page Introduction........................................................................................................ Tone Frequency ............................................................................................. Tone Type...................................................................................................... Tone Switching Source.................................................................................. DTMF Testing With Two Sources .....
291, 292, 294 Users Manual Introduction In tone mode the output is stepped through a user-defined list of up to 16 frequencies under the control of the signal set by the source soft key on the TRIGGER IN set-up screen. This signal can be the internal trigger generator, an external trigger input, the front panel MAN TRIG key or a remote command. On multi-channel instruments the control signal can also be the trigger out from an adjacent channel.
Tone Mode Introduction 8 there can be an off period between successive frequencies whilst the gate signal is not true. With type set to fsk the frequency changes instantaneously (and phasecontinuously) at each occurrence of the signal edge specified in the source and slope fields on the TRIGGER IN screen without completing the current waveform cycle; this is true FSK (frequency shift keying) tone switching.
291, 292, 294 Users Manual It is also possible to set up DTMF testing using two single channel instruments triggered by a common external signal and summed using the external SUM capability.
Chapter 9 Arbitrary Waveform Generation Title Page Introduction........................................................................................................ Arbitrary Waveform Terms ........................................................................... Principles of Arbitrary Waveform Creation and Modification...................... Selecting and Outputting Arbitrary Waveforms ................................................ Creating New Waveforms .........................................
291, 292, 294 Users Manual Introduction Arbitrary (arb) waveforms are generated by sequentially addressing the RAM containing the waveform data with the arbitrary clock. The frequency of the arb waveform is determined both by the arb clock and the total number of data points in the cycle. In this instrument an arb waveform can have up to 1,048,576 horizontal points. The vertical range is -2048 to +2047, corresponding to a maximum peak-to-peak output of 20 Volts.
Arbitrary Waveform Generation Selecting and Outputting Arbitrary Waveforms 9 These steps are fully described in the Creating New Waveforms and Modifying Arbitrary Waveforms sections which follow. Waveform creation using waveform design software also consists of two steps: 1. Creating the waveform using the software on a PC. 2. Downloading the waveform directly to the memory card (using the USB-connected card reader/writer) and inserting the card into the instrument.
291, 292, 294 Users Manual Creating New Waveforms Pressing the CREATE key calls the CREATE NEW WAVEFORM screen. CREATE NEW WAVEFORM create blank… create from copy… Create Blank Waveform Pressing the create blank… soft key calls the menu: create: size: cancel "WFM1 " 0001024 create The top line contains the user-defined waveform name which can be up to 8 characters long.
Arbitrary Waveform Generation Selecting and Outputting Arbitrary Waveforms 9 The horizontal size of the waveform being copied does not have to be the same as the waveform being created. When the waveform is copied, by pressing the create soft key, the software compresses or expands the source waveform to create the copy.
291, 292, 294 Users Manual Rename Waveform Pressing the rename… soft key on the MODIFY screen calls the Rename screen: Rename: WFM1 as: "WFM2 cancel " rename The new name can be entered below the original by selecting the appropriate character position with the cursor keys and then setting the character with the rotary control which scrolls through all the alphanumeric characters in sequence. The name can be up to 8 characters long.
Arbitrary Waveform Generation Selecting and Outputting Arbitrary Waveforms 9 Edit Waveform Pressing the edit wfm… soft key calls the EDIT FUNCTIONS menu: EDIT FUNCTIONS: point edit… line draw… wave insert… This menu provides functions which permit the waveform to be edited point-by-point (point edit), by drawing lines between two points (line draw) or by inserting all or part of an existing waveform into the waveform being edited (wave insert).
291, 292, 294 Users Manual default frm address is the first point on the waveform or the point most recently edited if point edit has been used. Set the from address and value by pressing the appropriate soft key and making an entry direct from the keyboard or by using the rotary control; repeat for the to address and value. The line will be drawn between the two selected points when the draw line soft key is pressed.
Arbitrary Waveform Generation Selecting and Outputting Arbitrary Waveforms 9 Press copy to implement the copy. During the two stage block copy process the screen displays the message processing file - please wait and shows a progress bar. During the first stage the block to be copied is created as a temporary file with the same name as the main file but with a $$$ extension; during the second stage the appropriate section of the original file is overwritten and the temporary file is deleted.
291, 292, 294 Users Manual Waveform Offset Pressing the wave offset soft key initiates the creation of a temporary copy of the waveform to be edited and calls the WAVE OFFSET screen. WAVE OFFSET: +0000 0000000 to 0000123 undo set offset save & exit save The waveform offset can be changed on a section of the waveform defined by the start and stop addresses. Set the addresses by pressing the appropriate soft key and making entries directly from the keyboard or using the rotary control.
Arbitrary Waveform Generation Arbitrary Waveform Sequence 9 POSITION MARKER EDIT adrs: 0000000 <0> patterns… exit clear all Position markers are output from SYNC OUT when the source (src) is set to pos’n marker on the SYNC OUTPUT SETUP screen. Position markers can be set at any or all of the addresses of a waveform either individually, using the adrs (address) soft key, or as a pattern, using the patterns… menu.
291, 292, 294 Users Manual Pressing the SEQUENCE key calls the initial SEQUENCE screen: SEQUENCE segs= sequence setup… stop 1 run A previously-defined sequence can be run and stopped from this screen using the run and stop soft keys; sequence can also be switched on from the STANDARD WAVEFORMS screen with the sequence soft key. The segs= field shows the number of segments in the sequence; there is always at least 1 segment.
Arbitrary Waveform Generation Frequency and Amplitude Control with Arbitrary Waveforms 9 chapter 7, Triggered Burst and Gate. At each trigger the current waveform cycle plus one further whole cycle are completed before the waveform of the next segment is started. If trig level is selected the sequence runs continuously through each segment in turn (one cycle per segment) while the trigger level is true.
291, 292, 294 Users Manual on a single channel instrument, or ARB FREQUENCY: ext source: ext arb clk freq: 10.0000000kHz on a multi-channel instrument. It is then possible to select the source to be either an external signal on the ARB CLOCK IN/OUT socket or the internal system clock; see the Reference Clock IN/OUT and System Clock Setting sections of Chapter 15, System Operations from the Utility Menu for the use of and frequency setting for the system clock.
Arbitrary Waveform Generation Sync Out Settings with Arbitrary Waveforms 9 Amplitude Pressing the AMPLitude key with an arbitrary waveform selected calls the AMPLITUDE screen. AMPLITUDE: +20·0 Vpp Vpp load:hiZ This differs from the AMPLITUDE screen for standard waveforms in that amplitude can now only be entered in volts peak-to-peak.
291, 292, 294 Users Manual Output Filter Setting The output filter type is automatically chosen by the software to give the best signal quality for the selected waveform. The choice can, however, be overridden by the user and this is most probably a requirement with arbitrary waveforms. To change the filter, press the FILTER key to call the FILTER SETUP screen: FILTER SETUP mode: auto type: 40MHz eliptic The default mode is auto which means that the software selects the most appropriate filter.
Chapter 10 Pulse and Pulse-trains Title Introduction........................................................................................................ Pulse Set-Up ...................................................................................................... Pulse-Train Set-Up ............................................................................................ Waveform Hold in Pulse and Pulse-Train Modes .............................................
291, 292, 294 Users Manual Introduction Pulse and pulse-trains are both selected and set-up from independent menus on the STANDARD WAVEFORMS screen called by pressing the STD key. Pulse and pulsetrains have similar timing set-ups and considerations but pulses are only unipolar, with a maximum amplitude of 10 V p-p, whereas pulse-trains can be bipolar, with a maximum peak-to-peak of 20 V p-p.
10 Pulse and Pulse-trains Pulse Set-Up waveform sync. Pressing the done soft key on this screen returns the display to the STANDARD WAVEFORMS screen. The means by which pulse period is set-up in the hardware requires an understanding because it affects the setting resolution of both pulse width and delay.
291, 292, 294 Users Manual ARB CLOCK IN/OUT socket, or to the system clock on multi-channel instruments. To select external clock mode press the PULSE PERIOD soft key on the PULSE PERIOD screen (or the PULSE FREQ soft key on the PULSE FREQ screen) to change from internal to external clock. The screen changes to, for example: PULSE PERIOD: ext source: ext arb clk on a single-channel instrument, or PULSE PERIOD: ext source: ext arb clk freq: 10.0000000kHz on a multi-channel instrument.
10 Pulse and Pulse-trains Pulse-Train Set-Up Pressing next on any screen calls the next set-up screen, finally returning the display to the STANDARD WAVEFORMS screen from which pulse-train can be turned on and off. Pressing done returns the display directly to the STANDARD WAVEFORMS screen from any set up screen. The pulse-train is built only after next is pressed after the last parameter set-up or whenever done is pressed, assuming a change has been made.
291, 292, 294 Users Manual The pulse level can be set on this screen between -5·0 V and +5·0 V by direct keyboard entries or by using the rotary control. As with the baseline level described above the set pulse levels are only output if the amplitude setting is set to maximum (10 V p-p into 50Ω) on the AMPLITUDE screen and terminated in 50 Ω.
10 Pulse and Pulse-trains Pulse-Train Set-Up generator, the individual pulse widths and delays are adjusted proportionally to the period as the period is changed. Period can also be changed from the PULSE-TRN PERIOD screen called by pressing the FREQ key with pulse-train mode selected: PULS-TRN PER: int 100·00000 us freq period The new setting can be entered either as a period in the way already described or as a frequency by first pressing the freq soft key.
291, 292, 294 Users Manual Note that the pulse-train waveform will continue to run from the internal clock until the instrument receives the first rising edge of the external clock; at that point the hardware switches over to the external source. In external clock mode the period of the pulse-train waveform is determined by the number of points in the waveform multiplied by the period of the external clock.
Chapter 11 Modulation Title Introduction........................................................................................................ External VCA ................................................................................................ External SCM ................................................................................................ Internal Modulation ...........................................................................................
291, 292, 294 Users Manual Introduction Both internal and external modulation can be selected. External modulation can be applied to any or all channels. Internal modulation uses the previous channel as the modulation source, e.g. channel 2 can be used to modulate channel 3; internal modulation is not available on channel 1 or on a single channel instrument. The external modulation mode can be set to VCA (voltage controlled amplitude) or SCM (suppressed carrier modulation) mode.
11 Modulation Internal Modulation gives warnings when the combination of modulation depth and amplitude setting cause waveform clipping (see Internal Modulation section), it is up to the user to observe the waveforms when using external VCA and to make adjustments if the waveform is clipping. Note that it is not possible to give a simple guide as to where the range breakpoints are because the use of dc offset, for example, changes these points.
291, 292, 294 Users Manual Warnings are given when either a modulation depth or output amplitude change has caused clipping; the new setting is accepted but it must either be changed back or the other parameter must also be changed to avoid the contention. When SCM is selected the screen has an additional soft-key labeled level; selecting this key permits the peak carrier output level to be set directly from the keyboard or by the rotary control. The maximum output level that can be set is 10 V p-p.
Chapter 12 Sum Title Page Introduction........................................................................................................ 12-2 External Sum...................................................................................................... 12-2 Internal Sum.......................................................................................................
291, 292, 294 Users Manual Introduction Both internal and external Sum can be selected; summing can be used to add ‘noise’ to a waveform, for example, or to add two signals for DTMF (Dual Tone Multiple Frequency) testing. External sum can be applied to any or all channels. Internal sum uses the previous channel as the source, so that for example channel 2 can be added into channel 3; internal sum is not available on channel 1 or on a single channel instrument.
12 Sum Internal Sum mid-range then the SUM signal needed to force the output to range maximum is halved to approximately 1 V p-p. To facilitate the setting of appropriate sum and amplitude levels the output amplitude of the selected channel can also be changed from the SUM set-up screen. Press the CHx soft-key and adjust the amplitude with direct keyboard entries or by using the rotary control. External sum cannot be used with internal modulation.
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Chapter 13 Synchronizing Title Introduction........................................................................................................ Inter-Channel Synchronization .......................................................................... Synchronizing Principles............................................................................... Master-Slave Allocation ................................................................................ Phase-Setting Between Channels .................
291, 292, 294 Users Manual Introduction Two or more channels in one multi-channel generator can be synchronized together and precise phase differences can be set between the channels. Two separate generators can also be synchronized, giving a maximum of 8 channels that can be operated synchronously.
13 Synchronizing Inter-Channel Synchronization The mode soft-key can be used to select between independent, master, master/freq and slave; the default mode is independent. Only one master can be set; more than one master can be selected but when synchronization is turned on with the status soft-key the set-up will be rejected. Master/freq selects the master and sets frequency-tracking; for this to be operational the master and slave(s) must be set to the same frequency when synchronization is turned on.
291, 292, 294 Users Manual Phase-Setting Between Channels The inter-channel set-up screen also has a field for setting up the phase of the slaves with respect to the master: mode: indep phase: +000.0º (actual: +000.0º status: off view Selecting the phase soft-key allows the phase to be set by direct keyboard entry or by rotary control. Setting the phase of a slave positive advances the waveform of the slave with respect to the master; setting it negative delays the slave with respect to the master.
13 Synchronizing Synchronizing two generators • Pulse and pulse train waveforms will synchronize to other pulse and pulse-train waveforms (and with each other) but should be built with equal periods. • Arb waveforms should be the same length (although this is not forced and does not create an error message). When synchronization is turned on with the status soft-key the slaves are re-synchronized automatically after every phase or frequency setting change.
291, 292, 294 Users Manual Connections for Synchronization The clock connection arrangement is for the rear panel REF CLOCK IN/OUT of the master (which will be set to master) to be connected directly to the REF CLOCK IN/OUT socket of the slave (which will be set to slave). Similarly the synchronizing connection is from any SYNC OUT of the master, which all default to phase lock, to the TRIG IN input of the slave.
13 Synchronizing Synchronizing two generators Hardware delays become increasingly significant as frequency increases, causing additional phase delay between the master and slave. However, these delays can be largely nulled out by ‘backing off’ the phase settings of the slave. Typically these hardware delays are as follows: DDS waveforms: <± 25 ns <1 ° to 100 kHz Clock synthesized waveforms: <300 ns <1 ° to 10 kHz.
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Chapter 14 Memory Card Title Introduction........................................................................................................ Card Sizes and Formats ..................................................................................... Formatting.......................................................................................................... Saving Files to a Memory Card ......................................................................... Avoiding Long Filenames ..........
291, 292, 294 Users Manual Introduction Pressing the UTILITY key calls a list of menus which give access to various system operations including storing/recalling set-ups from a memory card, error messages, power on settings and calibration. The instrument uses compact flash memory cards, i.e. cards that comply with the Compact Flash Association standard. A compatible memory card and a USB card reader/writer are supplied with the instrument.
14 Memory Card Formatting where waveforms are stored, and \SETUP.ARB, where instrument set-ups are stored. The instrument will use these directories exclusively for its files. Each directory may hold up to 510 files, disk capacity permitting. If more than 510 files are stored in these directories some will be invisible to the instrument because its directory cache buffers are a finite size.
291, 292, 294 Users Manual Pressing STORE (or store…) calls the screen: Save to store: "SETUP22 " execute A unique store name must be entered using the left and right cursor keys and the rotary control. The left and right keys step the edit cursor through the eight possible character positions of the name and the rotary control is used to scroll through all possible character choices.
14 Memory Card Sorting Files Sorting Files To make it easier to find a particular set-up in a long list it is recommended that the setups on the card are first sorted into alphabetical order using the sort dir… soft key on the MEMORY CARD screen: DIRECTORY SORT sort waveforms sort setups cancel Press the appropriate soft-key to sort the directory; pressing either sort, or cancel returns the display to the MEMORY CARD screen.
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Chapter 15 System Operations from the Utility Menu Title Introduction........................................................................................................ Channel Waveform Information ........................................................................ Warnings and Error Messages ........................................................................... Remote Interface Set-Up....................................................................................
291, 292, 294 Users Manual Introduction Pressing the UTILITY key calls a list of menus which give access to various system operations including storing/recalling set-ups from a memory card, error messages, power on settings and calibration. Each of the following operations is accessed by pressing the appropriate soft key on the UTILITY MENU. Press UTILITY again at any time to return to the main utility menu.
15 System Operations from the Utility Menu Power On Setting The ARB CLOCK IN/OUT socket is set to input by setting sys clk to off and to an output by setting it to on. When sys clk is on (set to output) it is also used as the external clock when a channel is set to use an external arb clock. The system clock frequency may be set by numeric entry or rotary control. Note that the system clock frequency also controls the frequency of the aux sine output on the rear panel.
291, 292, 294 Users Manual Calibration Pressing calibration calls the calibration routine, as described in chapter 16, Calibration. Copying Channel Set-Ups An easy way of copying complete channel set-ups (waveform, frequency, amplitude, etc.) is accessed by pressing the COPY CHannel key: copy channel: 1 to channel: 2 execute The first line of the screen shows which channel is currently selected with the channel SETUP keys.
Chapter 16 Calibration Title Introduction........................................................................................................ Equipment Required .......................................................................................... Calibration Procedure ........................................................................................ Setting the Password...................................................................................... Password Access to Calibration .....
291, 292, 294 Users Manual Introduction All parameters can be calibrated without opening the instrument case; the generator offers ‘closed-box’ calibration. All adjustments are made digitally with calibration constants stored in EEPROM. The calibration routine requires only a digital voltmeter (DVM) and a frequency counter and takes no more than a few minutes. The crystal in the timebase is pre-aged but a further ageing of up to ±5 ppm can occur in the first year.
16 Calibration Calibration Routine Enter a 4-digit password from the keyboard; the display will show the message NEW PASSWORD STORED! for two seconds and then revert to the UTILITY menu. If any keys other than the numeric keys 0 to 9 are pressed while entering the password the message ILLEGAL PASSWORD! will be shown. The password is held in EEPROM and will not be lost when the memory battery back-up is lost.
291, 292, 294 Users Manual The full procedure (for the 4-channel instrument) is as follows: CAL 03 CAL 04 CAL 05 CAL 06 CAL 07 CAL 08 CAL 09 CAL 10 CAL 11 CAL 12 CAL 13 CAL 14 CAL 15 CAL 16 CAL 17 CAL 18 CAL 19 CAL 20 CAL 21 CAL 22 CAL 23 CAL 24 CAL 25 CAL 26 CAL 27 CAL 28 CAL 29 CAL 30 CAL 31 CAL 32 CAL 33 CAL 34 CAL 35 CAL 36 CAL 37 CAL 38 CAL 39 CAL 40 CAL 41 CAL 42 CAL 43 CAL 44 CAL 45 CAL 46 CAL 47 CAL 48 CAL 49 CAL 50 CAL 51 CAL 52 CAL 53 CAL 54 CAL 55 16-4 CH1 DC offset zero.
16 Calibration Calibration Routine CAL 56 CAL 57 CAL 58 CAL 59 CAL 60 CAL 61 CAL 62 CAL 63 CAL 64 CAL 65 CAL 66 CAL 67 CAL 68 CAL 69 CAL 70 CAL 71 CAL 72 CAL 73 CAL 74 CAL 75 CAL 76 CAL 77 CAL 78 CAL 79 CAL 80 CAL 81 CAL 82 CAL 83 CAL 84 CAL 85 CAL 86 CAL 87 CAL 88 CAL 89 CAL 90 CAL 91 CAL 92 CAL 93 CAL 94 CAL 95 CAL 96 CAL 97 CAL 98 CAL 99 CAL 100 CAL 101 CAL 102 CAL 103 CAL 104 CAL 105 CAL 106 CAL 107 CAL 108 CAL 109 CAL 110 CH2 Level 35 MHz CH2 Level 37·5 MHz CH2 Level 40 MHz CH3 DC offset zero.
291, 292, 294 Users Manual CAL 111 CAL 112 CAL 113 CAL 114 CAL 115 CH4 Level 32·5 MHz CH4 Level 35 MHz CH4 Level 37·5 MHz CH4 Level 40 MHz Clock calibrate Adjust for same reading Adjust for same reading Adjust for same reading Adjust for same reading Adjust for 10·00000 MHz at SYNC OUT Remote Calibration Calibration of the instrument may be performed over the RS232 or GPIB interface.
Chapter 17 Remote Operation Title Introduction........................................................................................................ Address and Baud Rate Selection ...................................................................... Remote/Local Operation.................................................................................... RS232 interface.................................................................................................. Single Instrument RS232 Connections.
291, 292, 294 Users Manual Introduction The instrument can be remotely controlled via its RS232, USB or GPIB interfaces. When using RS232 it can either be the only instrument connected to the controller or it can be part of an addressable RS232 system which permits up to 32 instruments to be addressed from one RS232 port.
17 Remote Operation RS232 interface RS232 interface The 9-way D-type serial interface connector is located on the instrument rear panel. The pin connections are as shown in chapter 3, Connections. Single Instrument RS232 Connections For single instrument remote control only pins 2, 3 and 5 are connected to the PC. However, for correct operation links must be made in the connector at the PC end between pins 1, 4 and 6 and between pins 7 and 8; see diagram.
291, 292, 294 Users Manual 9-WAY D FEMALE DCD 1 RX 2 9-WAY D MALE 1 2 TX 3 3 DTR 4 4 GND DSR 5 6 5 6 RTS 7 7 CTS RI 8 9 8 9 UP TOWARDS CONTROLLER 1 2 3 4 5 6 7 8 9 9-WAY D INSTRUMENT CONNECTOR MALE TX RX TX RX GND DOWN TOWARDS OTHER INSTRUMENTS TXIN RXOUT shc0012f.emf Figure 17-3.
17 Remote Operation RS232 interface return to non-addressable mode the Lock Non-Addressable mode control code must be sent which will disable addressable mode until the instruments are powered off. Before an instrument is sent a command it must be addressed to listen by sending the Listen Address control code, 12H, followed by a single character which has the lower 5 bits corresponding to the unique address of the required instrument, e.g.
291, 292, 294 Users Manual Full List of Addressable RS232 Interface Control Codes 02H Set Addressable Mode. 03H Universal Unaddress control code. 04H Lock Non-Addressable mode control code. 06H Acknowledge that listen address received. 0AH Line Feed (LF); used as the universal command and response terminator. 0DH Carriage Return (CR); formatting code, otherwise ignored. 11H Restart transmission (XON). 12H Listen Address − must be followed by an address belonging to the required instrument.
Remote Operation GPIB Interface 17 GPIB Subsets This instrument contains the following IEEE 488.1 subsets: Source Handshake Acceptor Handshake Talker Listener Service Request Remote Local Parallel Poll Device Clear Device Trigger Controller Electrical Interface SH1 AH1 T6 L4 SR1 RL1 PP1 DC1 DT1 C0 E2 GPIB IEEE Std. 488.2 Error Handling The IEEE 488.2 UNTERMINATED error (addressed to talk with nothing to say) is handled as follows.
291, 292, 294 Users Manual The bits in the PPE command are as follows: bit 7 = bit 6 = bit 5 = bit 4 = bit 3 = bit 2 = bit 1 = bit 0 = x 1 1 0 sense ? ? ? don't care parallel poll enable sense of the response bit; 0 = low, 1 = high bit position of the response For example: to return the RQS bit (bit 6 of the Status Byte Register) as a 1 when true and a 0 when false in bit position 1 in response to a parallel poll operation, send the following commands: *PRE 64, then PPC followed by 69H (PPE) The
17 Remote Operation Status Reporting Status Byte Register and Service Request Enable Register These two registers are implemented as required by the IEEE std. 488.2. Any bits set in the Status Byte Register which correspond to bits set in the Service Request Enable Register will cause the RQS/MSS bit to be set in the Status Byte Register, thus generating a Service Request on the bus.
291, 292, 294 Users Manual Power-On Settings The following instrument status values are set at power-on: Status Byte Register =0 Service Request Enable Register † =0 Standard Event Status Register = 128 (pon bit set) Standard Event Status Enable Register † =0 Execution Error Register =0 Query Error Register =0 Parallel Poll Enable Register † =0 † Registers marked thus are specific to the GPIB section of the instrument and are of limited use in an RS232 environment.
Remote Operation Remote commands 17 The commands are not case-sensitive. GPIB Remote Command Formats GPIB input to the instrument is buffered in a 256 byte input queue which is filled, under interrupt, in a manner transparent to all other instrument operations. The queue contains raw (un-parsed) data which is taken by the parser as required. Commands (and queries) are executed in order and the parser will not start a new command until any previous command or query is complete.
291, 292, 294 Users Manual : a short mnemonic or string such as ON or OFF. A number in any format. For example, 12, 12.00, 1.2 e 1 and 120 e-1 are all accepted as the number 12. Any number, when received, is converted to the required precision consistent with the use, then rounded up to obtain the value of the command. A number with no fractional part, i.e. an integer.
Remote Operation Remote commands Waveform Selection WAVE 17 Select the output waveform as , , , , , , , , , , , , or . PULSPER Set the pulse period to sec. PULSWID Set the pulse width to sec. PULSDLY Set the pulse delay to sec. PULTRNLEN Set the number of pulses in the pulse-train to . PULTRNPER Set the pulse-train period to sec.
291, 292, 294 Users Manual ARBCLR Delete the arb from channel memory. The backup memory is not changed. ARBCREATE , Create a new, blank arbitrary waveform with name and length points. ARBDEFCSV ,, Define a new or existing arbitrary waveform with name and length and load with the data in . If the arbitrary waveform does not exist it will be created.
Remote Operation Remote commands 17 Arbitrary Waveform Editing Care should be take to ensure that all channels in the instrument are running in CONTINUOUS mode before using commands from this section. Failure to observe this restriction may give unexpected results. ARBEDLMTS , Set the limits for the arbitrary waveform editing functions to start at and stop at .
291, 292, 294 Users Manual ARBDATACSV? Returns the data from an existing arbitrary waveform. must be the name of an existing arbitrary waveform. The data consists of ascii coded values as specified for the ARBDATACSV command. The data is sent from the arbitrary waveform between the points specified by the ARBEDLMTS command. ARBDATA? Returns the data from an existing arbitrary waveform. must be the name of an existing arbitrary waveform.
Remote Operation Remote commands ARBCOPY ,, , Block copy in arbitrary waveform the data from start address to stop address to destination address . ARBAMPL ,, , Adjust the amplitude of arbitrary waveform in the address range to by the factor . ARBOFFSET ,, , Move the data in arbitrary waveform in the address range to by the offset .
291, 292, 294 Users Manual Mode Commands MODE BSTCNT Set the burst count to . PHASE Set the generator phase to degrees. This parameter is used for setting the trigger/gate mode start/stop phase and the phase difference when synchronizing channels. TONEEND Delete tone frequency number thus defining the end of the list. TONEFREQ ,, Set tone frequency number to Hz.
Remote Operation Remote commands FORCETRG Modulation Commands MOD Force a trigger to the selected channel. Will function with any trigger source except MANUAL specified. Set the modulation source to , or . MODTYPE Set the modulation type to or . AMDEPTH Set the depth for amplitude modulation to %. SCMLEVEL Set the level for SCM to volts. SUM Set the sum source to , or .
291, 292, 294 Users Manual *IDN? Returns the instrument identification. The exact response is determined by the instrument configuration and is of the form , , 0, where is the manufacturer’s name, defines the type of instrument and is the revision level of the software installed. *IST? Returns ist local message as defined by IEEE Std. 488.2. The syntax of the response is 0, if the local message is false or 1, if the local message is true.
Remote Operation Remote commands Miscellaneous Commands *LRN? 17 Returns the complete set up of the instrument as a hexadecimal character data block. To re-install the set up the block should be returned to the instrument exactly as it is received. The syntax of the response is LRN . The settings in the instrument are not affected by execution of the *LRN? command.
291, 292, 294 Users Manual Returns the instrument to local operation and unlocks the keyboard. LOCAL Will not function if LLO is in force. Returns the instrument's address. UCBID? Refer to chapter 16, Calibration, for remote calibration commands. Remote Command Summary Table 17-1. Remote Command Summary *CLS *ESE Clear status. *ESE? Returns the value in the Standard Event Status Enable Register in numeric format.
Remote Operation Remote Command Summary *TST? The generator has no self−test capability and the response is always 0. *WAI Wait for operation complete true. executed before the next is started ABORT Aborts a phase locking operation. AMDEPTH Set the depth for amplitude modulation to %. AMPL Set the amplitude to in the units as specified by the AMPUNIT command. AMPUNIT Set the amplitude units to , or .
291, 292, 294 Users Manual ARBINSSTD ,, , Insert the standard waveform into the arbitrary waveform from start address to stop address . ARBINVERT ,, Invert arbitrary waveform between start address and stop address . ARBLEN? Returns the length, in points, of the arbitrary waveform .
Remote Operation Remote Command Summary FORCETRG Force a trigger to the selected channel. HOLD Set hold mode , , or . LOCKMODE Set the channel synchronization mode to , , or . LOCKSTAT Set the channel synchronization status to or . LOCAL Returns the instrument to local operation and unlocks the keyboard. Will not function if LLO is in force.
291, 292, 294 Users Manual 17-26 PULTRNWID , Set the width of pulse−train pulse number to sec. QER? Query and clear query error number register. REFCLK Set the REF CLOCK IN/OUT to , , or . SCMLEVEL Set the level for SCM to Volts. SETUPCH Select channel SEQCNT , Set count for sequence segment to . SEQSEG , Set the status of sequence segment to or .
Remote Operation Remote Command Summary TONEFREQ ,, Set tone frequency number to Hz. The third parameter sets the tone type; 1 will give trig, 2 will give FSK, any other value gives gate type. TRIGIN Set the trig input to , , , , , or . TRIGLEV Set the trigger threshold level to volts. TRIGOUT Set the trig output to , , , or .
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Chapter 18 Maintenance Introduction........................................................................................................ 18-2 Cleaning .............................................................................................................
291, 292, 294 Users Manual Introduction The manufacturers or their agents overseas will provide a repair service for any unit developing a fault. Where owners wish to undertake their own maintenance work, this should only be done by skilled personnel in conjunction with the service manual. Cleaning If the instrument requires cleaning use a cloth that is only lightly dampened with water or a mild detergent.
Appendices Appendix A B C D E F G Title AC Supply Voltage ............................................................................................. Warning and Error Messages .............................................................................. SYNC OUT Automatic Settings ......................................................................... Factory System Defaults ..................................................................................... Waveform Manager Plus..................
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Appendix A AC Supply Voltage Introduction Before connecting the instrument to an ac outlet, check that the instrument operating voltage marked on the rear panel is correct for the local supply. Warning To avoid the possibility of electric shock, always ensure the instrument is disconnected from the ac supply before opening the case. Changing the Supply Voltage Setting If it is necessary to change the operating voltage, proceed as follows: Single channel instrument model 291 1.
291, 292, 294 Users Manual shc0003f.gif Figure 1-1. Mains transformer connections 5. To comply with safety standard requirements the operating voltage marked on the rear panel must be changed to clearly show the new voltage setting. 6. Change the fuse to one of the correct rating; see below. 2- and 4-channel instruments models 292 and 294 These instruments have a universal input range and will operate from a nominal 100 V, 115 V or 230 V mains supply without adjustment.
Appendix B Warning and Error Messages Introduction Warning messages are given when a setting may not give the expected result, e.g. dc offset attenuated by the output attenuator when a small amplitude is set; the setting is, however, implemented. Error messages are given when an illegal setting is attempted; the previous setting is retained. The last two warning or error messages can be reviewed by selecting LAST ERROR from the UTILITY screen. The latest is reported first.
291, 292, 294 Users Manual Error Messages 101 Frequency out of range for the selected waveform 102 Sample clock frequency required exceeds 100 MHz 103 Sample clock frequency required is less than 0.
Appendices Warning and Error Messages B 182 Waveform is too long for the available channel memory 184 Sum or modulation conflict 186 Inter channel lock not possible. Lock status is off. This error may occur for several reasons. In each case there is a conflict of the synchronization settings. In most cases the status of the synchronization is set to off. Any of the following conditions will cause this error: 1. More than one master channel is enabled. 2. No master channel is enabled. 3.
291, 292, 294 Users Manual 190 Memory card missing. Waveform not loaded 191 Set-up file not found. Loading defaults OR Waveform not found Critical Stop Errors These errors have no obvious recovery path and require user intervention. Some can be bypassed by a key press, some offer a choice of action. Possible hardware failures may be firmware induced and recover by cycling the power. Firmware errors all require a power cycle to recover.
Appendix C SYNC OUT Automatic Settings Introduction The following automatic source (src) settings are made when auto mode is selected on the SYNC OUT screen. MODE Continuous Waveform Position WAVEFORM Sync Marker Standard 9 Arbitrary 9 Sequence Gate/Trig All Sweep All Tone Burst Done Sequence Sync Ext.
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Appendix D Factory System Defaults Introduction The factory system defaults are listed in full below. They can be recalled by pressing RECALL followed by set defaults or by the remote command *RST. All channels will receive the same set-up. All channels default to the same settings. Main Parameters: Std.
291, 292, 294 Users Manual D-2 Sweep Parameters: Begin frequency: End frequency: Marker frequency: Direction: Spacing: Sweep time: Type: 100 kHz 40 MHz 10 MHz Up Log 10 ms Continuous Filter Auto Sync out Auto Sequence Status: Wfm: Step on Count: all segments set as follows: Off except seg 1. None selected Count 1 Arbitrary All unaffected by reset or *RST.
Appendix E Waveform Manager Plus Waveform Manager Plus Arbitrary Waveform Creation and Management Software The Waveform Manager Plus program allows construction, editing, exchange, translation and storage of many types of waveform data. It is compatible with many popular DSOs and many waveform generation products. Waveforms may be generated by equation entry, freehand drawing, combining existing waveforms or any combinations of these methods.
291, 292, 294 Users Manual 2. Some dialog boxes have a Help button which, when clicked, will open the on-line help file at the section containing the description of that dialog box. 3. From most windows and dialogues the F1 key will open the help file at the relevant section. Waveform Manager allows you to keep waveforms for different projects separate from each other on your hard drive.
Appendix F Block Diagrams Internal trigger generator TRIG IN front panel BNC Trigger out from Ch(n -1) Trigger out from Ch(n+1) Waveform end marker Trig in TRIGGERING Position Sequence end Burst done Manual / remote trigger Ext lock in from another instrument Internal lock in from this instrument Master clock in/out Ch(n) carrier Mod/sum out from Ch(n-1) Lock out, routed via SYNC OUT BNC, if this instrument is the master PHASE LOCKING Modulation in front panel BNC Sum in front panel BNC Trigger
291, 292, 294 Users Manual Internal lock in Manual/remote trigger Internal trigger gen TRIG IN BNC SUM IN BNC MODULATION IN BNC EXT ARB CLOCK IN/OUT Master clock I I I I I I Channel 1 I/O I I I OO N/C I I I I I I Channel 2 I/O Ch1 mod/sum out I I I OO I I I I I I Channel 3 I/O I I I OO Ch2 mod/sum out I I I I I I Channel 4 I/O I I I OO Ch3 mod/sum out Trig out Ch 1 N/C Trig out Ch 2 System Clock Trig out Ch 3 Trig out Ch 4 shc0009f.emf Figure F-2.
Appendix G Front and Rear Panel Drawings shc0014f.gif Figure G-1.
291, 292, 294 Users Manual shc0015f.gif Figure G-2. Model 292 Front Panel shc0016f.gif Figure G-3. Model 294 Front Panel shc0017f.gif Figure G-4.
Appendices Front and Rear Panel Drawings G shc0018f.gif Figure G-5.
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Index —A— AC supply, 2-2 adding waveforms, 12-2 address, remote, 17-2 addressable RS232, 17-3, 17-4 adjacent channel trigger, 7-3 amplitude modulation, 1-9 arb clock in, 1-9, 3-4 arb clock out, 1-9 arb waveforms, 9-2 amplitude, 9-9, 9-15 block copy, 9-8 copying, 9-4, 9-8 creating, 9-4 editing, 9-7 external clock, 9-13 frequency, 9-13 hold, 9-15 information, 9-6 insert wave, 9-8 inversion, 9-10 markers, 9-10 modifying, 9-5 offset, 9-10 principles, 9-2 renaming, 9-6 selecting, 9-3 sequence, 9-11 sync out, 9-
connector GPIB, 17-6 RS232, 17-3 USB, 17-6 copy channel, 15-4 —D— daisy chain, 1-11, 17-3 data entry, 4-3 dc offset attenuation, 5-4 DDS mode, 4-6 delays hardware, 13-7 direct digital synthesis, 4-5, 4-6 display, 4-2 DTMF, 1-7, 8-3, 12-2 dual tone multi-frequency, 1-7 —E— editing principles of, 4-3 error messages, 5-5, 15-2 external clock, 9-13, 10-3, 10-7 external trigger, 7-2 —F— features, 1-2 filter, 1-5, 9-16 flash card reader, 14-2 forced trigger, 7-5 formatting memory card, 14-3 frequency sequence,
Index (continued) manual hold, 10-8 marker patterns, 9-11 master-slave, 13-2 memory card, 9-3 directories, 14-2 format, 14-2 formatting, 14-3 saving files, 14-3 slot, 3-5 sorting files, 14-5 menu utility, 15-2 message reviewing, 5-6 settings, 5-6 messages errors and warnings, 5-5, 15-2 remote, B-3 mode clock synthesis, 4-5 DDS, 4-6 gated, 1-6, 7-6 pulse, 10-2 sweep, 1-6 tone, 8-2 tone switching, 1-7 triggered burst, 1-6 modes of operation, 1-6 modulation internal, 11-3 SCM, 11-3 VCA, 11-2 modulation in, 1-
status model, 17-9 step on criterion, 9-12 sum, 12-2 sum in, 1-9, 3-3 supply cable, 2-2 supply voltage, 2-2 suppressed carrier modulation, 1-9 sweep connections, 6-2 duration, 6-4 marker, 6-5 mode, 1-6 principles, 6-2 spacing, 6-5 span, 6-3 sync, 3-2, 5-6 time, 6-3 type, 6-4 sync out, 3-2 arb waveforms, 9-15 sync out key, 5-6 synchronization, 1-10, 13-2 between instruments, 13-5 connections:, 13-6 within instruments, 13-2 synchronize, 13-3 SYS/REF Clock, 15-2 system clock, 1-8 System Clock Setting, 15-2 sys
