OPERATING MANUAL MULTIPLE OUTPUT LINEAR SYSTEM DC POWER SUPPLIES Agilent MODELS 6621A, 6622A, 6623A, 6624A, and 6627A Agilent Part No 5957-6377 Agilent Model 6621A, Serials 3213A-01681 and Agilent Model 6622A, Serials 3210A-02091 and Agilent Model 6623A, Serials 3209A-02231 and Agilent Model 6624A, Serials 3210A-06721 and Agilent Model 6627A, Serials 3209A-00841 and Above* Above* Above* Above* Above* * For instruments with higher Serial Numbers, a change page may be included. Microfiche Part No.
CERTIFICATION Agilent Technologies certifies that this product met its published specifications at time of shipment from the factory. Agilent Technologies further certifies that its calibration measurements are traceable to the United States National Bureau of Standards, to the extent allowed by the Bureau’s calibration facility, and to the calibration facilities of other International Standards Organization members.
SAFETY SUMMARY The following general safety precautions must be observed during all phases of operation, service, and repair of this instrument. Failure to comply with these precautions or with specific warnings elsewhere in this manual violates safety standards of design, manufacture, and intended use of the instrument. Agilent Technologies assumes no liability for the customer’s failure to comply with these requirements. BEFORE APPLYING POWER.
SAFETY SUMMARY (continued) GENERAL Any LEDs used in this product are Class 1 LEDs as per IEC 825-1. ENVIRONMENTAL CONDITIONS This instrument is intended for indoor use in an installation category II, pollution degree 2 environment. It is designed to operate at a maximum relative humidity of 95% and at altitudes of up to 2000 meters. Refer to the specifications tables for the ac mains voltage requirements and ambient operating temperature range.
DECLARATION OF CONFORMITY according to ISO/IEC Guide 22 and EN 45014 Manufacturer’s Name: Agilent Technologies Manufacturer’s Address: 150 Green Pond Road Rockaway, New Jersey 07866 U.S.A.
WHAT THIS MANUAL CONTAINS This is the Operating manual for the Agilent 6621A through 6624A and 6627A Series of Multiple Output Linear System Power Supplies. It contains information relating to the installation, operation, and programming of these supplies as outlined below. Maintenance and troubleshooting instructions are given in a separate Service Manual (Agilent Part No. 5957-6379). Chapter 1.
Table Of Contents 1 General Information Introduction............................ .......................................................................................................................11 Safety Considerations....................................................................................................................................11 Instrument and Manual Identification.... .......................................................................................................
Table Of Contents (continued) Positive and Negative Voltages.................................................................................................................49 Remote Voltage Sensing..................... ..........................................................................................................49 Remote Sense Connections................... ....................................................................................................50 Output Noise Considerations.........
Table Of Contents (continued) Setting Voltage................................. .........................................................................................................84 Setting Current...........................................................................................................................................84 Enabling/Disabling an Output...................... .............................................................................................
1 General Information Introduction This chapter contains a general description of your power supply, as well as its performance specifications. Information about options, accessories, and GP-IB cables is also provided. This manual describes all five models in the Agilent 6621A6624A, and 6627A power supply family. Unless stated otherwise, the information in this manual applies to all of these models. Information that is specific to one model only is identified as such in this manual.
Accessories 10833A GP-IB cable, 1 m (3.3 ft) 10833B GP-IB cable, 2 m (6.6 ft) 10833C GP-IB cable, 4 m (13.2 ft) 10833D GP-IB cable, 0.5 m (1.6 ft) 10834A GP-IB connector extender Slide mount kit (1494-0059) Description The Agilent 6621A-6624A, and 6627A Multiple Output Linear Power Supplies feature a combination of programming capabilities and linear power supply performance that make systems applications.
Programmable delay time for service request and OCP mask. Voltage, current, and overvoltage calibration. GP-IB interface selftest. Message display capability on the front panel. Output connections are made to rear panel screw terminals. Either the positive or negative output terminal can be grounded, or the output can be floated up to ± 240 Vdc (including output voltage) from chassis ground.
The power supply has no potentiometers. Each output is individually calibrated over the GP-IB using calibration commands (see Appendix A). Correction factors are calculated by the power supply during calibration and are stored in a non-volatile memory which is located on the supply’s GP-IB board. The supply contains no batteries. Output Boards The output boards are linear dc power supplies. Each isolated output has the L-shaped operating curve described in Description, page 12 and Figure 1-1.
Specifications Table 1-2 lists the performance specifications for the Agilent 662xA power supplies. Performance specifications describe the instrument’s warranted performance. The service manual, Option 9l0, contains procedures for verifying the performance specifications. Table 1-3 lists the supplemental characteristics for the Agilent 662xA supplies. Supplemental characteristics are type-tested or typical values, which are based on a product sample and, while representative, are not guaranteed.
Programming resolution: Average programming step size. Current Sinking ( - Current): Each output can sink as well as source current. The sinking capability is not programmable and depends upon the output voltage. The current sinking capability is described in greater detail in Chapter 4. Figure 1-3.
Table 1-2. Specifications PERFORMANCE SPECIFICATIONS (0 to 55°C unless otherwise specified) Outputs: 40 W Low 40 W High 80 W Low 80 W High Voltage Voltage Voltage Voltage DC Output Ranges: All outputs will accept voltage programming commands 1% higher than those listed and current programming commands 3% higher than those listed. Also, the minimum programmable current values are slightly above zero amps for each output. (See Table 5-4).
Table 1-3. Supplemental Characteristics Outputs 40 W Low Voltage 40 W High Voltage 80 W Low Voltage 80 W High Voltage (60 ppm + 1 mV)/ °C (160 ppm +0.1 mA)/°C (130 ppm + 2 mV)/ °C (60 ppm + 0.4 mV)/ °C (160 ppm +0.4mA)/°C (130 ppm + 1 mV)/ °C (60 ppm + 1 mV)/ °C (160 ppm +0.2 mA)/°C (130 ppm + 2 mV)/ °C (40 ppm +0.7 mV)/°C + 23 mV (85 ppm +0.1 mA)/°C +1 mA (95 ppm +0.1 mA)/°C +1.2 mA (40 ppm +0.3 mV)/°C + 10 mV (85 ppm +0.5 mA)/°C +5 mA (95 ppm +0.6 mA)/°C +6 mA (40 ppm +0.
Outputs Table 1-3. Supplemental Characteristics (continued) 40 W Low 40 W High 80 W Low 80 W High Voltage Voltage Voltage Voltage Programming Resolution: Voltage +Current OVP 6 mV 25 mA 100 mV 15 mV 10 mA 250 mV 6 mV 50 mA 100 mV 15 mV 20 mA 250 mV 6 mV 2 mA 15 mV 0.8 mA 6 mV 4 mA 15 mV 1.6 mA Readback Resolution: Voltage + or-Current Fixed Overvoltage Protection: (Measure at output terminals +V and -V): Minimum Nominal Maximum 22.5 V 24 V 26 V 56 V 60 V 64 V 22.
Table 1-3. Supplemental Characteristics (continued) Output Impedance: Approximated by a resistance in parallel with an inductance (see graphs in Figure 1-7). The values for each output are: 40 W Low Voltage 40 W High Voltage 80 W Low Voltage 80 W High Voltage 0.15Ω, 2.0µH 0.3 Ω, 5 µH 0.15 Ω, 0.8 µH 0.5 Ω, 3 µH Safety Agency Compliance: This series of power supplies is designed to comply with the following standards: IEC 348, UL 1244, and CSA 22.2 No. 231. Dimensions: (all models) Height = 132.
Figure 1-4.
Figure 1-5.
Figure 1-6.
Figure 1-7.
2 Installation Introduction This chapter contains instructions for checking and mounting your power supply, connecting your supply to ac power, converting it from one line voltage to another, and connecting the GP-IB cable. The power supply generates operating magnetic fields which may affect the operation of other instruments. If your instrument is susceptible to magnetic fields, do not locate it in the immediate vicinity of the power supply.
Figure 2-1. Outline Diagram Input Power Requirements You can operate this power supply from a nominal 100 V, 120 V, 220 V or 240 V single phase power source at 47 to 66 Hz. The input voltage range, maximum input current, high line inrush current (PK), and the fuse required for each of the nominal inputs are listed in Table 2-1. You can check the line voltage setting of your supply by examining the door on the line module. This is located on the rear panel of your supply as shown in Figure 2-2.
GP-IB Figure 2-2. Rear Panel Detail (6624A Shown) Table 2-2 Line Fuses Agilent Part Number (for 1/4 X 1-1/4 in. fuses only) 100/120 V 8AM 2110-0342 220/240 V 4AM 2110-0055 Note All fuses are rated for 250 V. Line Voltage Fuse Needed Figure 2-3.
Power Cord The power supply is shipped from the factory with a power cord that has a plug appropriate for your location. Figure 2-4 shows the standard configuration of plugs used by Agilent Technologies. Below each drawing is the Agilent part number for the replacement power cord equipped with a plug of that configuration. If a different power cord is required, contact the nearest Agilent Technologies Sales and Service office.
FIRE HAZARD Make sure the replacement fuse is one of the same type (size) and rating (amps) that is consistent with the voltage level you are operating at. Do not use a substitute fuse; use a fuse with the same Agilent Part number listed in Table 2-2. 6. Close the door of the line module and insert the power cord in the ac input socket. Your power supply is now configured to operate at the voltage you selected.
3 Getting Started Introduction This chapter is intended for the first time user of the supply. It provides four main discussions: • • • • Front Panel Controls and Indicators Turning on Your Supply Checking Out Your Supply Using Local Control Introduction to Remote Operation First, the supply’s front panel controls and indicators are briefly described. Some of the controls and indicators will be used in the Turn On and Checkout procedures that follow.
If you have any questions concerning installation or power requirements, review Chapter 2. To turn on your supply, press the front panel LINE switch. When the power is initially applied, the supply performs a series of self tests which last about 3 seconds. Included in these tests are checks of circuits on the GP-IB board and on each of the output boards. 3 5 1 6 7 8 6624A SYSTEM DC POWER SUPPLY SYSTEM 5.15V 1 2 3 4 -- OUTPUT -- CV CC LCL 2.
Number Table 3-1. Controls and Indicators (continued) Controls/lndicators Description Page 3 OUTPUT Annunciators Indicate which output channel has been selected for front panel control and/or display. (Only one output annunciator can be on at a time.) 36, 37, 83, 83 4 Power Supply Status Annunciators CV - Indicates that the selected output channel is in the constant voltage mode. 37, 43, 83 (These five annunciators indicate the status of the power supply).
Table 3-1. Controls and Indicators (continued) Controls/lndicators Description Number 7 Output Control Keys (These twelve keys are output dependent). 34 Getting Started Page OUTPUT SELECT - Selects one of the output channels for local control or display. This key allows the channels to be selected in forward (Ï) or reverse (Ð) sequence. 36, 37, 83, 83 VSET - Displays the selected output’s present voltage setting. The setting can be changed using the numeric entry keys.
Number 8 Table 3-1. Controls and Indicators (continued) Controls/lndicators Description Numeric Entry Keys (These keys are used in conjunction with many of the System Control and Output Control keys to enter the desired values into the power supply. Page 37, 83, 84 0 to 9 - Set the value of the specified function and (e.g. VSET 16.550) ←(backspace) - Erases the previous keystroke. Depressing this key without setting a value places the display in the metering mode.
Figure 3-4. Typical Display at Power-On Self-Test Errors If the supply fails the power-on self-test, all power supply outputs will remain disabled (off) and the display will indicate the type of failure and the output channel on which it occurred. Figure 3-5 shows that self-test detected an error in output channel 3. Error messages that could appear on the display if self-test fails are listed below.
Voltage Test 1. Set the voltage of the selected output to 10 V by pressing: VSET 1 0 ENTER 2. Check that the display reads approximately 10 V and 0 A and the CV annunciator is on indicating that the supply is in the constant voltage mode of operation. Overvoltage Test 1. Program the overvoltage protection (OVP) to 19 V by pressing: OV SET 1 9 ENTER 6 ENTER 2. Set the voltage to 16 V by pressing: VSET 1 3. Check that the display reads approximately 16 V and 0 A. 4.
7. Set the current to 0.5 A by pressing: ISET . 5 ENTER 8. Check that the display reads approximately 0 V and 0.5 A. 9. Enable the overcurrent protection circuit by pressing: OCP 10. Check that the OCP ENBLD annunciator is on indicating that overcurrent protection is enabled and the display reads "OVERCURRENT". When in overcurrent, the output is disabled. 11. Disable the overcurrent protection circuit by pressing: OCP 12. Reset the output by pressing: OC RST 13.
OUTPUT The Agilent BASIC language statement that addresses the power supply to talk and reads back data from the power supply is: ENTER The supply’s front panel ADDR annunciator is on when the supply is addressed to talk or to listen. Reading the GP-IB Address Before you can operate your power supply remotely, you need to know its GP-IB address. The address was displayed during the power on sequence described in Normal Self Test Indications, page 35.
Getting Data From The Supply The supply is capable of measuring the values of its output parameters in response to queries. In this example, the query asks the supply to measure the output voltage at output 1. When you send a query from remote, the supply does not display the response as it did when you executed the command from the front panel. Instead, it holds the response in an output buffer.
To set the voltage of output 1 to 5 volts, send: OUTPUT 705; "VSET 1,5" To set the current of output 2 to 450 milliamps, send: OUTPUT 705; "ISET 2,.450" Output Voltage and Current Measurement. You can instruct the supply to measure the actual output voltage and current at a specified output using the VOUT? and IOUT? queries, respectively.
Overcurrent Protection. The output will go to the off state (0 volts and min. current) when the overcurrent protection (OCP) feature is enabled and the output is in the + CC mode. To enable the overcurrent protection mode for output 2, send: OUTPUT 705; "OCP 2,1" To disable the overcurrent protection mode for output 2, send: OUTPUT 705; "OCP 2,0" When overcurrent protection is disabled and the output is in + CC mode, the output current will be limited to and will stay at the ISET value.
4 Output Connections and Operating Information Introduction This chapter explains how to make connections to the output terminals located on-the rear of your power supply. Some general operating information is included in this chapter to help you understand how the power supply operates under various load conditions. This information applies whether you are operating the supply via the front panel or the GP-IB.
Operating Quadrants Figure 4-2 shows the operating locus of your power supply in three quadrants. The area in quadrant 1 shows the operating locus defined by the voltage and current settings of each output. The characteristics shown for quadrant 1 incorporate remote sensing and include the maximum available sense voltage plus load lead drop. The area in quadrant 2 indicates the locus where each output can operate as a current sink. You cannot program current limit values in quadrant 2.
Figure 4-2.
A fixed overvoltage threshold of approximately 120% of the maximum rated output voltage is built into each output. Because the fixed overvoltage circuit is biased from the output terminals, it can be activated and provide protection even when the supply is not connected to the ac power line. The OVRST command restores the programmed voltage and current values and clears the OV once the cause of the overvoltage has been eliminated.
Figure 4-3 Typical Downprogramming Characteristic Below 2.0 V Wire Size Selection FIRE HAZARD Select a wire size large enough to carry short-circuit current without overheating. Two factors must be considered when selecting wire size for load connections: conductor temperature and voltage drop. To satisfy safety requirements, load wires must be heavy enough not to overheat while carrying the short-circuit output current of the unit.
available in the load leads for prolonged operation into a 5 A load during ac low line at high ambient temperature conditions. There is a similar stipulation for 80 W low voltage outputs at l0 A under the same conditions as above. See Figure 4-2A for worst case voltages available at the output terminals. Table 4-1.
Multiple Loads If you are using the as-shipped terminal block strapping pattern (local sensing) and are connecting multiple loads to one output, connect each load to the output terminals using separate connecting wires (see Figure 4-4). This minimizes mutual coupling effects and takes full advantage of the power supply’s low output impedance. Each pair of wires should be as short as possible and twisted or bundled to reduce lead inductance and noise pickup.
regardless of how the power supply is programmed. Note that with remote sensing, voltage readback monitors the load voltage at the sense points. Figure 4-5. Remote Voltage Sensing Figure 4-6. Allowable Load Lead Voltage Drop with Remote Sensing The maximum voltage available at the power supply output terminals during remote sensing (see Figure 4-6) is the maximum voltage (20.2 V or 50.5 V) rating, plus one volt (i.e. 21.2 V or 51.5 V as shown in Figure 4-2).This allows a voltage drop of 0.
OUTPUT TYPE (40 W & 80 W) FORMULA LV Output CV Reg Error(mV) = Rs ( Vset Vdrop ) 45 1.1 HV Output CV Reg Error(mV) = Rs ( Vset Vdrop ) 105 3.3 CV Regulation Error = Remotely sensed voltage will change by this number of millivolts. Rs = Resistance of each sense lead in Ω. Vset = Programmed voltage value in volts. Vdrop = Total drop in the load leads in volts. In addition, include ±1 mV error per 200 mV drop in the -V load lead independent of Rs value.
Overvoltage Trigger Connections Each output of your power supply has two OV terminals on its rear panel terminal block. These terminals are labeled +OV and -OV. By connecting the OV terminals all in parallel as shown in Figure 4-7, an overvoltage shutdown on any one output will also trigger the overvoltage on the remaining outputs. Any number of OV terminals up to eight sets can be strapped together. Observe polarity when connecting the OV terminals in parallel. Figure 4-7.
Figure 4-8. External Trigger Circuit The internal equivalent OV circuit is shown in Figure 4-9. Note the internal DC blocking capacitor, bleed resistor and noise bypass capacitors. Do not exceed 50 volts maximum between the + OV and the - OV terminals. The OV terminals are rated at ±240 Vdc (including external OV voltage) from chassis ground or any other output terminals. Figure 4-9.
Power Supply Protection Considerations Battery Charging If you are using your supply in a battery charging application, it is recommended that a series protection diode be added to prevent damage to the supply during an overvoltage shutdown. Remember that each output has an overvoltage protection circuit that fires a crowbar to disable the output for any of the OVERVOLTAGE conditions described in Protection Features, page 44.
CV Operation For CV operation, one output must operate in CC mode and the other output must operate in CV mode. Although each output operates independently of the other, the output that is operating in CV mode will be ’’controlling" the voltage regulation of both outputs. Setting the output voltages as outlined in the following paragraph and configuring the outputs as shown in Figure 4-11 will allow output 1 to operate in CV mode and output 2 to operate in CC mode. Figure 4-11.
CC Operation For CC operation, set the output voltages as outlined in CV operation (page 55), or alternatively, program the voltage settings of both outputs to the same voltage limit point. Then program the current of each output so that the sum of both currents equals the total desired operating current. The simplest way to accomplish this is to program each output to one half of the total desired operating current. Both outputs will operate in the CC mode.
Series Operation SHOCK HAZARD Floating voltages must not exceed 240 Vdc. No output terminal may be more than 240 Vdc from chassis ground. Connect in series only outputs that have equivalent current ratings. Each output has a reverse voltage protection diode across its output terminals. The current conducted by this diode is not internally limited by the output.
CC Operation For CC operation, the current setting of each output must be programmed to the desired operating current. The sum of the voltage settings determines the voltage limit point. As an example, one way to program the voltage of the output is to set the voltage of each output to one half of the total voltage limit point.
Voltage All series specifications referring to voltage are twice the single output specification except for programming resolution which is the same as for a single output. Current All series specifications referring to current are the same as for a single output except for CC load effect, CC load cross regulation, CC source effect, and CC short term drift which are twice the current programming accuracy (including the percentage portion).
5 Remote Operation Introduction Chapter 3 introduced you to the basics of remote operation and provided a few simple examples using a Series 200 computer as the GP-IB controller. This chapter contains all the information required to control your power supply remotely and discusses in greater detail how each of the commands can be implemented. The material covered is intended for any controller capable of using the GP-IB interface functions mentioned in Interface Function, on this page.
The SRQ annunciator on the front panel display is turned on when the power supply is requesting service from the computer and remains on until the controller conducts a serial poll. A serial poll removes the service request and turns off the SRQ annunciator regardless of whether the condition that caused the service request continues to exist. The service request is also removed when you send the "CLR" command (see page 73). Remote/Local.
Power-On Service Request (PON) The power supply can request service from the controller when the power is turned on. This request can be enabled or disabled by sending a PON command (see page 77). When the request is enabled, the supply can generate an SRQ at power-on or when there is a momentary loss in power. You can execute a serial poll to clear the service request. Table 5-7 details the conditions under which a PON command will generate an SRQ.
Figure 5-2 (Sheet 1 of 2).
Figure 5-2 (Sheet 2 of 2).
Table 5-1. Power Supply Commands Command Header *Output Channel Data Range Set Voltage VSET 1,2,3,4 See Table 5-4 Set Current ISET 1,2,3,4 See Table 5-4 Set Overvoltage OVSET 1,2,3,4 See Table 5-4 OC Protection On/Off OCP 1,2,3,4 0,1(off,on) Output On/Off OUT 1,2,3,4 0,1(off,on) Set the State of all DCPON ---0,1(off,on) CC+ Outputs at Power-On 2,3 (off,on) CCUnmask UNMASK 1,2,3,4 0-255 Reprogram Delay DLY 1,2,3,4 0-32 (LSB=0.
NOTES: 1. Output channels 3 and 4 are not used in all models. (See Table 5-4). 2. Applies to 80 W Low V output. 3. Applies to 40 W High V and 80 W High V outputs. 4. ’’X’’ depends upon model. 5. A space is returned for a + sign. 6. All responses are followed by a < CR > and < LF > (EOI asserted with < LF > ). 7. Spaces are allowed between the header and the question mark. Order of Execution When you send a set of instructions to the power supply, they are executed in the order in which they are received.
The output voltage of some output channels exceeds the safe operating limit of 42.2 V. To avoid any electrical shock, program the voltage to zero volts or turn off ac input power before changing any rear panel connections. Make certain all straps are properly connected, terminal block screws are securely tightened and terminal block covers are replaced before reapplying power. Voltage Programming To program voltage, send the output channel and the programmed value.
IOUT? 1 The results are placed on the GP-IB and read into the controller . Table 5-4. Programmable Output Ranges for the Agilent 662lA-6624A and 6627A Supplies Overvoltage Model Output Operating Output Voltage Output Range(Avg. Current-(Avg. Channel Range * (Avg. Resolution Resolution) Resolution) ** 6621A 1&2 Low 0 to 7.07 V 0.13 to 10.30 A 0 to 23 V (80 W Low V) High 0 to 20.2 V 0.13 to 4.12 A (0.10 V) (0.006 V) (0.050 A) 6622A 1&2 Low 0 to 20.2 V 0.07 to 4.12 A 0 to 55 V (80 W High V) High 0 to 50.
Range Switching Each output operates in the boundaries of either the low range or the high range as specified in Table 5-4. Refer to page 43 for a detailed description of the dual range operation. The range is selected based on the programmed parameters. If the last parameter (voltage or current) programmed is outside of the existing range, the supply will automatically switch ranges. A sequence of examples are given on the next page to illustrate this operation.
Overvoltage (OV) Protection The programmable OV is a protection feature which can be set by the operator to protect the load against excessive voltage. When the actual voltage exceeds the programmed overvoltage setting for a given output channel, the OV is tripped. The OV circuit will fire the SCR crowbar which shorts across the output and the output assumes a low impedance state. For example, to program the OV of output channel 1 to 9.5 V send the following command: OVSET 1,9.
Multiple Output Storage & Recall The power supply has 10 internal registers each of which can store the voltage and current settings of all the outputs. By storing voltage and current settings for all outputs and recalling them later, you can have significant savings in programming time. (See Supplemental Characteristics in Table 1-1). At power-on, each of the registers contain 0 volts and the minimum current limit. To store voltage and current settings, you must specify the register (1 to 10).
Figure 5-3. Functional Relationship of Status Registers The supply has one serial poll register which services all outputs and provides the user with other power supply statusrelated information as discussed on page 75. Status Register. Each output channel of the power supply maintains its present status in an 8-bit register. This status register reports the status of the output channel whenever it is queried. A "1" in any of the bit positions indicates that the condition is true.
To query an output channel for its status, you must specify the output channel. For example, to find out the status at output 2 send the following query and address the supply to talk: STS? 2 Accumulated Status Register. Each output channel of the power supply also maintains a cumulative status in its accumulated status (astatus) register. This register records every status condition the power supply output entered since it was last queried.
As shown in Figure 5-3, if one or more bits in the fault register of a given output channel are set, then the FAU bit for that output in the serial poll register will also be set and a service request may be generated (see page 76). To read the fault register of output 2 and find out which bits are set, send the following query and address the supply to talk: FAULT? 2 The power supply responds with a number which can be decoded from Table 5-5.
To find out the nature of the service request, you must do a serial poll. This will isolate the output that generated the request by checking which of the FAU bits are set in the case of a fault, or checking to see if the error bit is set in the case of an error. If the SRQ on faults was set, then send the fault query. FAULT? 2 (using output 2 as an example) and address the supply to talk if you want to find out which of the conditions you unmasked in Figure 5-3 are true.
If you want to disable this facility, send the command. PON 0 If you want to find out if the power-on SRQ is enabled or disabled, send the following query: PON ? and address the supply to talk. The supply will respond with a 1 or 0 as discussed above. NOTE The power-on (PON) SRQ mode is stored in the non-volatile memory of the supply so that although the supply may be switched off, it will remember the status of the last PON command at power-on and respond accordingly.
and address the supply to talk. The response will be a numeric value between 0 and 32. Display On/Off When the display is on, the commands sent across the GP-IB may experience a slower processing time because the processor must also spend time to monitor the outputs and update the display. You can shorten your command processing time by turning off the display.
the test query are described in Table 5-9. This test cannot be done from the front panel. To instruct the power supply to carry out a self-test, send the following query and address the supply to talk: TEST? Calibration Mode Query. To be able to calibrate your power supply, the calibration mode (CMODE) must be turned on (See Appendix A for a detailed description of the calibration procedure).
Front Panel Response GP-IB Code Table 5-8. Error Messages Explanation . NO ERROR 0 This is the response to the ERR? query when there are no errors. INVALID CHAR 1 You sent the supply a character it did not recognize. INVALID NUM 2 Format of your number is incorrect. Check number syntax. INVALID STR 3 or 28 Occurs when you send a command the supply does not understand. SYNTAX ERROR 4 Either too many parameters are sent without delimiters or the number representation is incorrect.
Front Panel Response CAL LOCKED SKIP SLF TST Code 0 GP-IB Code 18 22 Table 5-8. Error Messages (continued) Explanation Calibration was attempted with the Calibration Jumper on the GP-IB board in the lockout position. Reposition jumper if desired. See Service Manual. The self test jumper on the GP-IB board is in the Skip Self Test position. No self-test was done. This is for diagnostics only. See Service Manual. Table 5-9.
6 Local Operation Introduction Chapter 3 introduced you to the supply’s front panel controls and indicators to help you turn on the supply and perform the checkout procedures that were given in that chapter. The following paragraphs describe how to use all of the front panel controls and indicators. Most of the remote operations described in Chapter 5 can also be performed locally from the supply’s front panel.
SETTING FUNCTION OUTPUT FUNCTION KEYS LOCAL MODE KEY 6624A SYSTEM DC POWER SYSTEM VSET 2 1 2 3 4 -- OUTPUT -- 1.250 LCL CV CC UNR OCP ERR RMT ADDR SRQ ENBLD OUTPUT ENTRY ADDR METER OV SET OUTPUT SELECT 7 8 9 ERR DLY OV RST VSET 4 5 6 STO UN MASK OCP ISET 1 2 3 RCL FAULT OC RST OUTPUT ON/OFF 0 . ENTER LINE ON OFF OUTPUT CHAN 2 SYSTEM FUNCTION KEYS NUMERIC ENTRY KEYS Figure 6-1.
Enabling/Disabling an Output The selected output channel can be turned on and off from the front panel. The OUTPUT ON/OFF key toggles the selected output on and off. When an output is turned off, the message ’’DISABLED" will be displayed. The OUTPUT ON/OFF key will not affect any other programmed functions nor will it reset an overvoltage or overcurrent condition. An output disabled by the OUTPUT ON/OFF key will behave as if it were programmed to zero volts and minimum current.
Bit Position Bit Weight Condition Table 6-1. Bit Arrangement of the Status, Mask, and Fault Registers 7 6 5 4 3 2 1 128 64 32 16 8 4 2 CP OC UNR OT OV -CC +CC 0 1 CV Note that bits can be set in an output’s fault register only when there is a change in either the status register or the mask register. Therefore, if a bit is set in the mask register (unmasked) while the corresponding condition is true in the status register, the associated bit will also be set in the fault register.
The supply’s present address will appear in the display. Address 5 is the factory set address. If you want to leave the address set at 5, you can return to the metering mode by pressing the METER key or you can press another function key. If you want to change the address, you can enter a new value. Any integer from 0 through 30 can be selected.
A Calibration Procedures Introduction This appendix discusses the software calibration procedures for the power supply. These supplies should be calibrated annually or whenever certain repairs are made (see Service Manual). Because there are no internal or external hardware adjustments, your power supply can be calibrated without removing the covers or removing it from the cabinet if it is rack mounted. Calibration is performed by measuring actual output values and sending them to the supply over the GP-IB.
Figure A-1.
Command Table A-1. Calibration Commands Header Channel* Data Syntax Range (see Figure 5-2) Calibration Mode CMODE 0,1 (off,on) C2 Set High Voltage VHI 1,2,3,4 - C3 Set Low Voltage VLO 1,2,3,4 - C3 Set High Current IHI 1,2,3,4 - C3 Set Low Current ILO 1,2,3,4 - C3 Calibrate Overvoltage OVCAL 1,2,3,4 - C3 Voltage Data VDATA 1,2,3,4 see Table A-2 C5 see Table A-2 C5 Current Data IDATA 1,2,3,4 *Channels 3 and 4 are not used in all models.
Start with output channel 1 and use the following commands to calibrate your power supply: NOTE Do not turn the power supply off during the calibration procedures. Otherwise, the correction constants are not stored. Exercise care when moving the leads. 1. CMODE < param > - This command turns the calibration mode either on or off. The parameter must be either a 1 or a 0. CMODE1 is used in the beginning of the calibration procedure to turn calibration mode on.
Repeat commands two through eight for any other outputs that must be calibrated on your power supply. After you have completed calibration of all outputs, turn the calibration mode off by sending the CMODE0 command (see step 1) to the power supply. The correction constants are stored in memory at this time. Calibration Program The following calibration program can be used as is, provided you have an HP Series 200 computer with the BASIC programming language and an Agilent 3456A voltmeter.
470 ! 480 IF FNPs _ err < >0 THEN Finish 490 ! 500 OUTPUT @Ps;"VSET ";Chan,"0 ;ISET ’’;Chan,"0" 510 ! 520 INPUT "ANY MORE OUTPUTS TO CALIBRATE? (Y OR N)",X$ 530 IF (X$=’’Y" OR X$=’’y") THEN Start_loop 540 ! 550 OUTPUT @Ps;"CMODE 0" 560 ! 570 Finish: ! HERE WHEN DONE 580 OUTPUT @Ps;’’CLR" 590 DISP "END OF CALIBRATION PROGRAM" 600 END 610 ! 620 ! 630 DEF FNDvm 640 COM /Instr/ (@Ps,@Vm 650 WAIT.
LINE 370,380: Prompts the user to make current calibration connections and waits for CONTINUE key to be pressed. LINE 400: Sets the current of the specified output to the high calibration point. LINE 410: Sets the variable Ihi to the output current as measured by the voltmeter across the shunt resistor. Note that Ihi is in amps since the voltmeter returns volts and Shunt _ resistor is in ohms. LINE 430: Sets the current of the specified output to the low calibration point.
B Programming With a Series 200/300 Computer Introduction The purpose of this appendix is to serve as an introduction to programming your power supply with an HP Series 200/300 computer using the BASIC language. Examples are included that employ some of the most frequently used functions. These examples have been written so that they will run on any one of the five Agilent 6621A-6624A, and 6627A model power supplies.
Voltage and Current Programming With Variables You can use variables in a program to represent data values in the device commands. This is useful in applications that require changing the voltage and current values to different predetermined settings. The following program uses a variable in a FOR NEXT loop to ramp up output voltage in 0.1 volt steps from 0 to 5 volts. 10 ASSIGN @Ps TO 705 20 OUTPUT @Ps;"CLR;ISET1,1" 30 FOR Voltage=0 TO 5 STEP 0.1 40 OUTPUT @Ps;"VSET1,’’;Voltage 50 WAIT 0.
10 ASSIGN @Ps TO 705 20 OUTPUT @Ps;"VSET?1’’ 30 ENTER @Ps;Vsl 40 OUTPUT @Ps;’’ISET?1" 50 ENTER @Ps;Isl 60 PRINT ’’VOLTAGE SETTING OF OUTPUT #1 = ’’;Vsl 70 PRINT ’’CURRENT LIMIT SETTING OF OUTPUT #1 = ";Is1 80 END Line 10: Assigns the I/O pathname to the power supply. Line 20,30: Queries the supply for output 1’s voltage setting. You cannot string multiple queries together in a single device command because the power supply can only return the most recently queried data.
10 ASSIGN @Ps TO 705 20 COM /Ps/ @Ps 30 OUTPUT @Ps;’’CLR;UNMASK1,8;UNMASK2,8;SRQ1’’ 40 ON INTR 7,1 CALL Err _ trap 50 ENABLE INTR 7;2 60 OUTPUT @Ps;"OVSET1,4;0VSET2,4" 70 OUTPUT @Ps;"VSET1,5;VSET2,5" 80 Lbl: GOTO Lbl 90 END 100 ! 110 ! 120 SUB Err _ trap 130 OFF INTR 140 COM /Ps/ @Ps 150 IF BlT(SPOLL(@Ps),0) THEN 160 OUTPUT @Ps;’’OUT1,0;OVRST1’’ 170 PRINT ’’OVERVOLTAGE ON OUTPUT #1" 180 END IF 190 IF BIT(SPOLL(@Ps),1) THEN 200 OUTPUT @Ps;"OUT2,0;OVRST2" 210 PRINT "OVERVOLTAGE ON OUTPUT #2" 220 END IF 230 OU
Error Detection The power supply can recognize programming errors and can inform you when a programming error occurs. When an error is detected, no attempt is made to execute the command. Instead, a bit in the serial poll register is set. If SRQ2 or SRQ3 is set, an interrupt will be generated. The following program checks for programming errors and can be entered and run as is. While it is running, commands can be sent to the power supply from the keyboard.
LINE 10: Assigns the I/O path name to the power supply. LINE 20: Declare a common block for the I/O path name. LINE 30: Define interrupt on softkey depression and branch to error routine. LINE 40: Idle on softkey definition. LINE 80: Define subprogram Err_trap LINE 90: Disable interrupt capability while processing. LINE 100: Bring in the common block for the I/O pathname. LINE 110,120: Enter error code from power supply. LINE 130: Clears computer screen. LINE 140,150: If an error occurred, print message.
CC Operation Programming for CC operation is straightforward. Program each output to the desired voltage limit point. Then program each output to supply half of the total desired operating current. Both outputs will operate in CC mode. Note that the total desired current cannot exceed the combined current capability of both outputs. Figures 4-11 and 4-12 are examples of parallel configurations. These configurations apply to both CV and CC operating modes. Note the sense lead connections.
LINE 10: Assigns the I/O pathname to the power supply. LINE 20,30: Enter the operating voltage and current limit point. LINE 40: Sets C equal to one half of the current limit point. LINE 50-70: Determines the voltage setting for output 2. It is 20.2 V when the operating voltage is greater than 7 V, 7.07 V when the operating voltage is between 7 V and 2.5 V, and the same as the operating voltage below 2.5 V.
C Command Summary Introduction Table C-1 provides an alphabetical listing and a brief description of each command that can be sent to the Agilent 6621A24A, and 6627A power supplies. All of the commands can be executed remotely over the GP-IB. Many of the commands can also be executed locally from the supply’s front panel as indicated in the table. Command headers are accepted in upper or in lower case letters although only upper case letters are used in this summary.
Command Table C-l. Command Summary (continued) Description DSP? Queries the present status of the display (see page 78). Response is either a 1 (on) or a 0 (off). DSP " xxxxxxxxxxxx” Puts the quoted string on the power supply's front panel display (see page 79). Only numerals, upper case letters, and spaces are allowed (12 characters max) in the quoted string *ERR? Queries the present programming or hardware error (see page 79). An error code number is returned over the GP-IB to identify the error.
Command Table C-l. Command Summary (continued) Description OCP? < ch > Queries the overcurrent protection circuit on/off status for the specified output channel (see page 72). Response is either a 1 (on) or a 0 (off). The OCP ENBLD annunciator on the front panel displays the on/off status of the OCP circuit for the selected output. *OCRST < ch > Returns the specified output channel to the previous settings after it had been turned off by the overcurrent protection circuit (see page 72).
Command Table C-l. Command Summary (continued) Description SRQ? Queries the present setting of the reasons for issuing an SRQ (see page 76). Response is 0, 1, 2, or 3 that corresponds with the SRQ described previously. *STO < reg > Stores the present voltage and current settings for all output channels in the specified register (1 to 10); see page 72. These settings can be recalled when desired (see RCL command). STS? Queries the present status of the specified output channel.
D Error Codes and Messages Introduction This appendix describes the GP-IB error codes that can be readback to the controller and the error messages that can be displayed on the power supply’s front panel. A brief explanation of each code and message is also given. The error codes and/or messages fall into three categories: Power-on Self Test Messages, responses to the ERR? query, and responses to the TEST? query.
Table D-2. ERROR Responses Explanation Error Code (ERR? query) Message (ERR key) 0 NO ERROR 1 INVALID CHAR You sent the supply a character it did not recognize. 2 INVALID NUM The format of your number is incorrect. Check syntax (see Chapter 5). 3 or 28 INVALID STR You sent a command the supply does not understand. Resend a recognizable command. 4 SYNTAX ERROR You sent a command with improper syntax. Check syntax of your command (see Chapter 5).
Table D-2. ERROR Responses (continued) Explanation Error Code (ERR? query) Message (ERR key) 17 UNCALIBRATED 18 CAL LOCKED Calibration was attempted with the calibration jumper on the GP-IB board in the lockout position (See Chapter 4 in the Service Manual). Reposition the jumper and re-calibrate if this is desired. 22 SKIP SLF TST The self test jumper on the GP-IB board is in the Skip Self Test Position (See Chapter 4 in the Service Manual).
E Manual Backdating Introduction The backdating information in this section applies to units that have the following serial numbers: Agilent Model 6621A serials 2611A-00101 to 01680 Agilent Model 6622A serials 2611A-00101 to 02090 Agilent Model 6623A serials 2611A-00101 to 02230 Agilent Model 6624A serials 2550A-00101 to 06720 Agilent Model 6627A serials 2751A-00101 to 00840 Make Changes On page 28, replace the information in Line Voltage Conversion paragraph under steps number 2, 3, and 4 as follows: 2.
ADDENDUM I. Generally Applicable Annotations Consistent with good engineering practice, leads attached to customer accessible signal/monitoring ports (such as the l0-pin Control Connector, the 7-pin Analog Connector, the 7-pin Digital Port/Trigger Connector, screw terminal Barrier Blocks, etc.) should be twisted and shielded to maintain the instrument’s specified performance. II.
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Manual Updates The following updates have been made to this manual since the print revision indicated on the title page. 2/01/00 All references to HP have been changed to Agilent. All references to HP-IB have been changed to GPIB.
