User’s Guide LDX-3232 High Compliance Current Source ILX Lightwave Corporation · P. O. Box 6310 · Bozeman, MT, U.S.A. 59771 · U.S. & Canada: 1-800-459-9459 · International Inquiries: 406-556-2481 · Fax 406-586-9405 ilx.custhelp.com · www.ilxlightwave.
TA B L E O F C O N T E N T S TABLE OF CONTENTS Safety Information and the Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix General Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ix Safety Marking Symbols . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . x Comments, Suggestions, and Problems . . . . . . . . . . . . . . . . . . . . . . . . . . .
TA B L E O F C O N T E N T S Connecting to the Laser . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 Interlock Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 Photodiode Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Setting the PD Bias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Grounding Considerations . . . . . . . . . .
TA B L E O F C O N T E N T S Chapter 4 Command Reference LDX-3232 Device-Dependent Commands . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 LDX-3232 Device-Dependent Command Reference . . . . . . . . . . . . . . . . . . . . 40 Chapter 5 Functions and Features Saving and Recalling from the Front Panel . . . . . . . . . . . . . . . . . . . . . . . . . . 83 Saving and Recalling Under Remote Operation . . . . . . . . . . . . . . . . . . . . . . . 84 Using the Laser Compliance Voltage Adjustment .
TA B L E O F C O N T E N T S iv LDX-3232
LIST OF FIGURES LIST OF FIGURES Figure 1.1 LDX-3232 Front View . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 1.2 LDX-3232 Rear View . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 Figure 2.1 Common Laser Cathode - Photodiode Cathode . . . . . . . 11 Figure 2.2 Common Laser Cathode - Photodiode Anode . . . . . . . . 11 Figure 2.3 Common Laser Anode - Photodiode Cathode . . . . . . . . 11 Figure 2.4 Common Laser Anode - Photodiode Anode . . . . . . . . . . 12 Figure 2.
LIST OF FIGURES vi LDX-3232
L I S T O F TA B L E S LIST OF TABLES Table 2.1 LDX-3232 Default Settings. . . . . . . . . . . . . . . . . . . . . . . . . 10 Table 2.2 LDX-3232 Error Indicators . . . . . . . . . . . . . . . . . . . . . . . . . 19 Table 3.1 Substitute Parameter Names . . . . . . . . . . . . . . . . . . . . . . . 23 Table 3.2 LDX-3232 Often Used Commands . . . . . . . . . . . . . . . . . . 27 Table 3.3 LDX-3232 Default Settings for Output Off Registers . . . . . 30 Table 3.4 Error Code Classifications . . . . . . . . . .
L I S T O F TA B L E S viii LDX-3232
S A F E T Y A N D WA R R A N T Y I N F O R M A T I O N SAFETY AND WARRANTY INFORMATION The Safety and Warranty Information section provides details about cautionary symbols used in the manual, safety markings used on the instrument, and information about the Warranty including Customer Service contact information.
SAFETY SYMBOLS All instruments returned to ILX Lightwave are required to have a Return Authorization Number assigned by an official representative of ILX Lightwave Corporation. See Returning an Instrument on page xi for more information. SAFETY SYMBOLS This section describes the safety symbols and classifications. Technical specifications including electrical ratings and weight are included within the manual. See the Table of Contents to locate the specifications and other product information.
WA R R A N T Y Caution, risk of electric shock Protective Conductor Terminal Caution, hot surface On: In position of a bistable push control. The slash (I) only denotes that mains are on. or (I) Frame or chassis Terminal Off: Out position of a bistable push control. The circle (O) only denotes that mains are off. or (O) WARRANTY ILX LIGHTWAVE CORPORATION warrants this instrument to be free from defects in material and workmanship for a period of one year from date of shipment.
WA R R A N T Y 6 Send the instrument, transportation pre-paid, to ILX Lightwave. Clearly write the return authorization number on the outside of the box and on the shipping paperwork. ILX Lightwave recommends you insure the shipment. If the original shipping container is not available, place your instrument in a container with at least 3 inches (7.5 cm) of compressible packaging material on all sides. Repairs are made and the instrument returned transportation pre-paid.
WA R R A N T Y Comments, Suggestions, and Problems To ensure that you get the most out of your ILX Lightwave product, we ask that you direct any product operation or service related questions or comments to ILX Lightwave Customer Support. You may contact us in whatever way is most convenient: Phone . . . . . . . . . . . . . . . . . . . . . . . . . . . (800) 459-9459 or (406) 556-2481 Fax . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . (406) 586-9405 Online FAQ: . .
WA R R A N T Y in a container with at least 3 inches (7.5 cm) of compressible packaging material on all sides.
INTRODUCTION AND SPECIFICATIONS Product Overview CHAPTER CHAPTER 1 1 INTRODUCTION AND SPECIFICATIONS This chapter is an introduction to the LDX-3232 High Compliance Current Source. This chapter contains first time setup information, important safety considerations, maintenance information, instrument specifications, and general LDX-3232 information. If any of the following symptoms exist, or are even suspected, remove the LDX-3232 from service.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS Initial Inspection Initial Inspection When you receive your LDX-3232 instrument, verify that the following items were shipped with the instrument: • LDX-3232 High Compliance Current Source • LDX-3232 Series Instruction Manual • Power Cord • Shipping Kit Installing Your LDX-3232 High Compliance Current Source Grounding Requirements The LDX-3232 High Compliance Current Source comes with a three conductor AC power cable.
INTRODUCTION AND SPECIFICATIONS Installing Your LDX-3232 High Compliance Current Source CHAPTER 1 GPIB Connector The IEEE 488 GPIB interface connector is located on the rear panel, directly above the power input module and fuse. See Figure 1.2, LDX-3232 Rear View. Attach the GPIB cable to the 24-pin connector located on the rear panel. The connector is tapered to ensure proper orientation. Using your fingers, tighten the two screws on the cable connector.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS Installing Your LDX-3232 High Compliance Current Source Adjust Section Display Power Switch GPIB Section Parameter Selection Laser Mode Selection Current Range Selection Modulation Input Connector Figure 1.1 LDX-3232 Front View PD Bias Adjust Fan GPIB Connector LD Connector Trigger Output Connector Interlock Input Connector Figure 1.
INTRODUCTION AND SPECIFICATIONS Maintenance CHAPTER 1 Maintenance You may have to return your instrument to the ILX Lightwave facility at some time for repair or service whether or not it is under warranty. There is a charge for repairs after the warranty period has expired. Contact an ILX Lightwave service representative for shipping instructions prior to returning the instrument. Have the model number, instrument serial number, and a description of the problem or request at the time of the call.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS Specifications Specifications LDX-3232 Drive Current Output1 Output Current Range 0 to 2000 mA 0 to 4000 mA 40 µA 80 µA Setpoint Accuracy (% of FS) ±0.05% ±0.
INTRODUCTION AND SPECIFICATIONS Specifications CHAPTER 1 LDX-3232 Bandwidth (3 dB)9 DC to 250 kHz DC to 10 kHz DC to 250 kHz DC to 10 kHz Type TTL TTL Pulse Width 13 µs 13 µs Delay 12 ms 12 ms 0 to 2000.0 mA 0 to 4000.0 mA 0.1 mA 0.1 mA Photodiode Current Range 0 to 10,000 µA 0 to 10,000 µA Photodiode Current Resolution 1 µA 1 µA Photodiode Current Accuracy ±4 µA ±4 µA 0.00 to 1000.00 µA/mW 0.00 to 1000.00 µA/mW PD Responsivity Resolution 0.01 µA/mW 0.
CHAPTER 1 INTRODUCTION AND SPECIFICATIONS Specifications 8. Maximum monitor photodiode current drift over any 30 minute period. Assumes zero drift in responsivity of photodiode. 9. 50% modulation at mid-scale output. Higher bandwidth is possible with smaller magnitude modulation signal. 10.Similar resolution available over GPIB. 11.Responsivity value is user-defined and is used to calculate the optical power. 12.Four wire voltage measured at the load.
OPERATION Applying Power to Your LDX-3232 CHAPTER CHAPTER 2 2 OPERATION This chapter introduces you to the operation of the LDX-3232 High Compliance Current Source. It offers instructions for connecting your laser to the current source and describes powering up the instrument. This chapter also contains step by step procedures that teach you how to operate your current source in Constant Current Mode and Constant Power Mode.
CHAPTER 2 OPERATION Connecting to the Laser The Power On State You can choose to "clear" the last saved state by recalling the default values. These values are stored in BINS to that you can save or recall instrument configurations (described in more detail in Chapter 5). "BIN 0" contains all of the default configurations listed in Table 2.1. Note: If the instrument cannot successfully complete the power on test, an error message of E-512 or E-513 will be displayed on the Display.
OPERATION Connecting to the Laser CHAPTER 2 grounds in the circuit. Multiple earth grounds may provide circuit paths that induce spurious currents in the photodiode feedback circuit and output leads. Note: Cable connections to the laser must be secure! Loose connections can cause momentary open circuits that can damage the laser. Figures 2.1 - 2.4 show the possible configurations of connecting laser diodes and photodiodes with the LDX-3232 High Compliance Laser Current Source.
CHAPTER 2 OPERATION Connecting to the Laser OUTPUT LDX-3232 Current Source 7 + 6 Bias + 9 5 P. D. 3 L. D. Earth Ground Figure 2.4 Common Laser Anode - Photodiode Anode The 9-pin connector marked CURRENT SOURCE on the back panel is used to connect your laser diode to the LDX-3232. There are connections provided for laser cathode and anode, photodiode cathode and anode, chassis ground and interlock. The pinout diagram for this connector is shown in Figure 2.5.
OPERATION Connecting to the Laser CHAPTER 2 Photodiode Connections Many laser diode modules contain an internal photodiode that monitors the backfacet emission of the laser. Usually, this photodiode is internally connected to either the laser anode or cathode. The photodiode and laser connections to the LDX-3232 are electrically isolated from ground and each other. So, if a 4 pin connection is made (no common connections), no additional jumpers are required. Figures 2.1 - 2.
CHAPTER 2 OPERATION Front Panel Operation Front Panel Operation This section describes fundamentals of operation for your LDX-3232 in two operating modes: Constant Current (I) and Constant Power (P). The Display The digital display is used to show control parameters such as laser drive current (mA), laser current limit (mA), laser forward voltage (V), voltage limit (V), monitor photodiode current (µA), and laser optical power (mW) in both setpoint and measurement modes.
OPERATION Operating a Laser in Constant Current (I) Mode CHAPTER 2 Setting Up the Precision Current Source Set the LDX-3232 in Constant Current, low bandwidth mode by selecting I in the MODE section of the front panel. Do this by toggling the SELECT push button until the I indicator is illuminated. Repeatedly pressing the (MODE) SELECT switch cycles through the current (I), light power (P), or high-bandwidth current (IHBW) control modes.
CHAPTER 2 OPERATION Operating a Laser in Constant Current (I) Mode To set the current source limit, use the SELECT push button in the PARAMETER section of the front panel to select LIM I. Press and hold the (PARAMETER) SET push button and rotate the adjust knob to vary the limit setpoint value. Set the limit to 1750 mA. Once the (PARAMETER) SET push button is released, the new parameter value is stored in non-volatile memory.
OPERATION Operating a Laser in Constant Power (P) Mode CHAPTER 2 Conditions That Will Automatically Shut Off the LASER OUTPUT The following conditions will automatically cause the instrument to disable the current source output: • LASER High Power Limit • LASER Interlock / Key Lock Turned Off • LASER Open Circuit or Voltage Limit Operating a Laser in Constant Power (P) Mode Suppose you want to operate a 3 mW laser at constant 1mW level.
CHAPTER OPERATION Operating a Laser in Constant Power (P) Mode 2 A method to calculate the responsivity is suggested below. 1 Measure (with a calibrated detector) the output power of the device. 2 Measure the corresponding photodiode current. 3 Calculate the responsivity by dividing the photodiode current by the optical power noting the units required are µA/mW. The LDX-3232 High Compliance Current Source can be put into a special mode with the CAL PD parameter set to zero.
OPERATION Error Indicators CHAPTER 2 Now the instrument is configured to operate in Constant Power Mode. In the MODE section, enable the output of the laser current source by depressing the OUTPUT push button once. The accompanying LED labeled ON will illuminate indicating that the laser output is on and current is being driven to the laser. The LDX-3232 current source will drive the laser to the Constant Power setpoint and maintain closed loop control with the photodiode current measurement.
CHAPTER 20 LDX-3232 2 OPERATION Error Indicators
REMOTE OPERATION CHAPTER CHAPTER 3 3 REMOTE OPERATION Everything you learned to do from the front panel can also be done remotely and in some cases, with more flexibility. For instance, in remote mode, you have access to commands for functions not found on the front panel, such as commands that will increment (INC) and decrement (DEC) the current setpoint by a pre-defined step value.
CHAPTER 3 REMOTE OPERATION LDX-3232 Current Source Command Set Changing Operation from Local to Remote Sending a command over the GPIB will automatically put the instrument in REMOTE mode. The REMOTE indicator will identify when the Current Source is in remote operation mode. When the instrument is in REMOTE mode, pressing the LOCAL switch returns the instrument to LOCAL control mode unless the Local Lockout state has been activated by the host computer.
REMOTE OPERATION LDX-3232 Current Source Command Set CHAPTER 3 The syntax of the LDX-3232 High Compliance Current Source commands follows the rules laid out in the GPIB-IEEE488 standard. Colons (:) indicate the start of a new command path, while semicolons (;) indicate a separation of commands within a command string. A leading colon on a command may be used to return the LDX-3232 High Compliance Current Source command parser to the command path root (see Figure 3.1).
CHAPTER 3 REMOTE OPERATION LDX-3232 Current Source Command Set If multiple parameters are expected, they should be separated with commas: LAS:INC 100,50 A query has no space between the mnemonic and the question mark: LAS:LDI? The LDX-3232 High Compliance Current Source uses a terminator of <^END> (new line with EOI). For users whose GPIB driver defaults expect a carriage return in the terminator, <^END>, the TERM command may be used for convenience (see TERM command in Chapter 4).
REMOTE OPERATION Command Paths CHAPTER 3 Command Paths The LDX-3232 High Compliance Current Source device-dependent commands are structured into a tree format (see Figure 3.1). Each of the legal paths is listed below, followed by its list of path options, each of that is followed by the commands themselves. It is recommended that the first-time user begin learning the commands by using the full path notation.
CHAPTER 3 REMOTE OPERATION IEEE488.2 Command Commands IEEE488.2 Command Commands The IEEE488.2 Common Commands and Queries are distinguished by the "*" that begins each mnemonic. The diagrams below show the syntax structure for common commands, common commands with numeric data required, and command command queries.
REMOTE OPERATION LDX-3232 Frequently Used Commands CHAPTER 3 LDX-3232 Frequently Used Commands The LDX-3232 High Compliance Current Source’s complete command set contains over 60 commands that allow you to operate the current source for a variety of applications. Within the command set, however, is a smaller subset of commands that will meet most of your needs. These commands are listed in Table 3.2. Table 3.
CHAPTER 3 REMOTE OPERATION Status Reporting Status Reporting This section contains information that is relevant for understanding instrument error and statu reporting. It also contains information regarding the use of the instrument status for generating interrupts for interrupt driven programs or subroutines. Understanding the Operation Complete definition for the instrument is useful for programming synchronization.
REMOTE OPERATION Status Reporting 3 CHAPTER For example, the user may turn the current source on (LAS:OUT 1), enable an SRQ on Operation Complete (set *ESE 1 and *SRE 5), and have an SRQ handling routine in the user's software, that reads a new measurement after the output on state has been reached. This allows the use of the operation complete features of the LDX-3232, without the need for program looping or polling that can tie up the GPIB.
CHAPTER 3 REMOTE OPERATION Status Reporting Output Off Register The Output Off Enable Register allows you to determine that conditions and events in the LDX-3232 High Compliance Current Source can cause the current source output to be turned off. This reigster is configured in a manner similar to the status reporting registers. However, the register output is not reported in the Status Byte Register. Rather, it sets the hardware that controls the output switching.
REMOTE OPERATION Status Reporting CHAPTER 3 r 15 14 13 12 11 10 9 8 & 7 6 5 4 3 2 1 0 LASER Output Off Register & & & & & & Logical & & OR & & & & & & 15 14 13 12 11 10 9 8 Turn Output Off & 7 6 5 4 3 2 1 0 LASER Output Off Enable Register LASer:ENABle:OUTOFF LASer:ENABle:OUTOFF? Figure 3.
CHAPTER 3 REMOTE OPERATION Command Timing and Completion Command Timing and Completion This section describes, for each device-dependent command, whether that command is performed in an overlapped or sequential manner. In other words, it states whether the next command may begin while the current command is being executed, or if the next command must wait until the current command is completed before its execution begins.
REMOTE OPERATION Error Messages 3 CHAPTER (up to 10 may be stored). Reading the error queue via GPIB clears the error queue. Table 3.4 Error Code Classifications Error Code Range Area of Operation E-001 to E-099 Internal Program Errors E-100 to E-199 Parser Errors E-200 to E-299 Execution Control Errors E-300 to E-399 GPIB Errors E-500 to E-599 LASER Control Errors Table 3.
CHAPTER 34 LDX-3232 3 REMOTE OPERATION Error Messages Error Code Explanation E-501 LASER interlock disabled output E-503 LASER open circuit disabled output E-504 LASER current limit disabled output E-505 LASER voltage limit disabled output E-507 LASER power limit disabled output E-510 LASER out of tolerance disabled output E-511 LASER control error disabled output E-512 Analog section status is all 1’s or all 0’s (power down) E-513 Serial EEPROM checksum error E-515 Laser output mu
COMMAND REFERENCE CHAPTER CHAPTER 4 4 COMMAND REFERENCE This chapter is a guide to all of the device-dependent commands for the LDX-3232 High Compliance Current Source. This chapter is divided into two parts. The first part contains an overview of the remote commands used by the LDX-3232 High Compliance Current Source. The second part contains all of the LDX-3232 commands in alphabetical order. Figure 4.1 shows the format for the device command descriptions in this chapter.
CHAPTER 36 LDX-3232 4 COMMAND REFERENCE Name Parameters Function LAS:CAL:MDI? NONE Returns the ready state for entering the monitor photodiode current calibration value LAS:COND? NONE Returns the value of the LASER condition register LAS:DEC 0, 1 or 2 Used to decreate the laser current setpoint value by one or more steps LAS:DIS 1 Turns the LASER display on or off LAS:DIS? NONE Returns the LASER display value LAS:DIS:LDI NONE Turn on/off LASER display to show laser output current L
COMMAND REFERENCE 04_06 CHAPTER 4 Name Parameters Function LAS:LIM:I2 1 Used to set the LASER low range current source limit LAS:LIM:I2? NONE Used to return the LASER low range current source limit LAS:LIM:I4 1 Used to set the LASER high range current source limit LAS:LIM:I4? NONE Used to return the LASER high range current source limit LAS:LIM:MDP 1 Used to set the constant optical power (from monitor photodiode) limit value LAS:LIM:MDP? NONE Used to return the optical power (from m
CHAPTER 38 LDX-3232 4 COMMAND REFERENCE Name Parameters Function LAS:TOL? NONE Used to return the LASER setpoint tolerance value and time period value MES 1 Used to enter a string message of up to 16 bits MES? NONE Returns a previously stored ASCII message RAD 1 Sets the radix type for numerical data; decimal, binary, octal or hexadecimal RAD? NONE Used to return the radix type for numerical data TERM 1 Used to add a carriage return to the device terminator TERM? NONE Returns the
COMMAND REFERENCE LDX-3232 Device-Dependent Commands CHAPTER 4 LDX-3232 Device-Dependent Commands This section contains all of the device-dependent commands for the LDX-3232 High Compliance Current Source, listed in alphabetical order. Sub-sections for each path are presented, listing the commands that are legal for that path. See Figure 3.1 for command path tree structure. Command Path:Name Required letters are shown in upper case; lower case letters are optional.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LDX-3232 Device-Dependent Command Reference The following pages contain a reference for the device-dependent commands of the LDX-3232 High Compliance Current Source. This reference contains useful information for both local and remote operation of the LDX-3232. References to the front panel labels are capitalized in the following reference pages (as is done throughout this manual).
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference ERRors? CHAPTER 4 FRONT PANEL REMOTE The ERRors? query returns a list of command and device errors that have occurred since the last query. These errors are notated by a number that corresponds to the type of error that occurred. See Chapter 3 for information regarding error handling. Syntax Diagram : Parameters Notes Examples ERR ? None. The response data will be a list of the current errors.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:CALMD? FRONT PANEL REMOTE The LASer:CALMD? query returns the value of the laser's photodiode feedback responsivity (CAL PD parameter) setting. Syntax Diagram CALMD : LAS : ? CALPD Notes Examples If this value is 0, the LDX-3232 will be set to operate in constant IPD mode, and the IPD setpoint value will be in effect.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:CAL:LDI CHAPTER 4 FRONT PANEL REMOTE The LASer:CAL:LDI command is used to enter the LASER current setpoint, measurement, and limit (in low bandwidth mode) calibration mode. Syntax Diagram LDI : LAS : CAL : I Parameters Notes Examples 04_06 None Since the limit circuit is the same for both high and low bandwidth modes, it is only calibrated when low bandwidth mode is selected.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:CAL:LDI? FRONT PANEL REMOTE The LASer:CAL:LDI? query is used to determine that the LDX-3232 is ready for a value to be entered during the calibration cycle of the LASer:CAL:LDI mode. Syntax Diagram LDI : : LAS CAL : ? I Notes Examples After this query is issued and a response of 1 is received, the LDX-3232 will be ready for the user to enter a current value via the LASer:LDI command (see Chapter 6).
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:CAL:LDV? CHAPTER 4 FRONT PANEL REMOTE The LASer:CAL:LDV? query is used to determine that the LDX-3232 is ready for a value to be entered during the calibration cycle of the LASer:CAL:LDV mode. Syntax Diagram : Notes Examples LAS : CAL : ? LDV After this query is issued and a response of 1 is received, the LDX-3232 will be ready for the user to enter a voltage value via the LASer:LDV command (see Chapter 6).
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:CAL:MDI? FRONT PANEL REMOTE The LASer:CAL:MDI? query is used to determine that the LDX-3232 is ready for a value to be entered during the calibration cycle of the LASer:CAL:MDI mode. Syntax Diagram MDI : : LAS : CAL ? IPD Notes Examples After this query is issued and a response of 1 is received, the LDX-3232 be ready for the user to enter a photodiode current value via the LASer:MDI command (see Chapter 6).
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference Examples CHAPTER 4 Circuit condition is fleeting and may be missed via the LAS:COND? query. Therefore, the user should test for the Open Circuit Event via the LAS:EVEnt? query. The LASER condition status is constantly changing, while the event status is only cleared when the event status is read or the *CLS command is issued. "LAS:COND?" -response: 513, means that the LASER limit current and out of tolerance LASER conditions currently exist.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay FRONT PANEL REMOTE The LASer:DISplay command enables or disables (turns off) the display and some LEDs Syntax Diagram : Parameters Notes Examples LAS : DIS An ; -where 1 = on, 0 = off. Turning the display and LEDs off means that a message of all blank spaces is sent to the display, and most of the LEDs will be turned off.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay:LDI CHAPTER 4 FRONT PANEL REMOTE The LASer:DISplay:LDI command sets the laser display to show the constant current measurement. Syntax Diagram I : LAS : DIS : LDI Parameters Notes Examples None. The LDI measurement display mode is turned off automatically when another display selection is enabled. "LAS:DIS:LDI" -action: enables the display for current values.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay:LDV FRONT PANEL REMOTE The LASer:DISplay:LDV command sets the laser display to show the laser forward voltage measurement. Syntax Diagram V : LAS : DIS : LDV Parameters Notes Examples None The LDV measurement mode is turned off automatically when another display selection is enabled. "LAS:DIS:LDV" -action: enables the display for LDV measurement mode.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay:MDI 4 CHAPTER FRONT PANEL REMOTE The LASer:DISplay:MDI command sets the laser display to show the monitor photodiode current measurement. Syntax Diagram IPD : : LAS DIS : MDI Parameters Notes Examples None The MDI measurement display is turned off automatically when another display selection is enabled. "LAS:DIS:MDI" -action: enables the display for photodiode current measurement values.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay:MDP FRONT PANEL REMOTE The LASer:DISplay:MDP command sets the display to show the monitor photodiode power measurement. Syntax Diagram PPD : : LAS DIS : MDP Parameters Notes Examples None The MDP measurement display is turned off automatically when another display selection is enabled. "Las:Display:MDp" -action: enables the display for photodiode power measurement values.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay:PARAM CHAPTER 4 FRONT PANEL REMOTE The LASer:DISplay:PARAM command enables the display to show the parameter values. Syntax Diagram : Parameters Notes Examples : LAS : DIS PARAM None This command has the same effect as pressing the (PARAMETER) SELECT switch while in LASER mode. The selected parameter will be displayed for three seconds.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:DISplay:SET? FRONT PANEL REMOTE The LASer:DISplay:SET? query returns the status of the setpoint display mode. Syntax Diagram : Notes Examples LAS : : DIS SET ? - where the response is 0 or 1. The setpoint display will not time out when REMOTE operation is used. (It will be continuously displayed.) "LAS:DISPLAY:SET?" -response: 0, means the setpoint is not shown on the display.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference Examples CHAPTER 4 "LAS:ENAB:COND 129" -action: enables the LASER status condition register so that the Open circuit and LASER current limit conditions will be summarized in the status byte (bit 3). Laser:Enable:Cond #H0F9B" - action: enables the LASER status condition register so that any and all of the above conditions will be reported in the status byte register (bit 3).
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:ENABle:EVEnt FRONT PANEL REMOTE The LASer:ENABle:EVEnt command sets the status event enable register of the LASER operations. These events are summarized in bit 2 of the status byte register.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:ENABle:EVEnt? CHAPTER 4 FRONT PANEL REMOTE The LASer:ENABle:EVEnt? query returns the value of the status event enable register of the LASER operations.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:ENABle:OUTOFF FRONT PANEL REMOTE The LASer:ENABle:OUTOFF command sets the status outoff enable register of the LASER operations (things that will turn the LASER output off).
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference CHAPTER 4 . LASer:ENABle:OUTOFF? FRONT PANEL REMOTE The LASer:ENABle:OUTOFF? query returns the value of the status outoff enable register of the LASER operations.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:EVEnt? FRONT PANEL REMOTE The LASer:EVEnt? query returns the value of the status event register of the LASER operations.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:INC CHAPTER 4 FRONT PANEL REMOTE The LASer:INC command increments the selected laser control mode setpoint by one or more steps. Optional parameters allow multiple steps to be incremented and the time (in ms) between increments to be set, respectively. This is an overlapped command. Other commands may be executed while this function is in progress.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:LDI FRONT PANEL REMOTE The LASer:LDI command sets the laser control current. Syntax Diagram I : : LAS LDI Parameters Notes Examples An that represents the (laser) output current in mA. setpoint is the same for both low and high bandwidth output modes. "Las:LDI 400" -action: sets the laser output current to 400.00 mA. "LAS:ldi 100" -action: sets the laser output current to 100.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:LDV CHAPTER 4 FRONT PANEL REMOTE The LASer:LDV command sets the laser voltage for calibration of the laser voltage measurement. Syntax Diagram : Parameters Notes Examples LAS : LDV An that represents the (laser) output voltage, in volts. setpoint is the same for both low and high bandwidth output modes and is entered only for LDV calibration. "Las:LDV 4" -action: enters a value of 4.000 V.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:LIMit:I2 FRONT PANEL REMOTE The LASer:LIMit:I2 command sets the LASER current limit value for the 2000 mA range on the LDX-3232. Syntax Diagram : Parameters Notes Examples LAS : LIM : I2 An that represents the LASER limit current, in mA. The current limit is in effect in all modes of operation (ILBW, IHBW, or P).
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:LIMit:I4 CHAPTER 4 FRONT PANEL REMOTE The LASer:LIMit:I4 command sets the LASER current limit value for the 4000 mA range on the LDX-3232. Syntax Diagram : Parameters Notes Examples LAS : LIM : I4 An that represents the LASER limit current, in mA. The current limit is in effect in all modes of operation (ILBW, IHBW, or P).
CHAPTER COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference 4 LASer:LIMit:MDP FRONT PANEL REMOTE The LASer:LIMit:MDP command sets the laser monitor photodiode power limit value. Syntax Diagram MDP : : LAS : LIM P Parameters Notes Examples An that represents the laser monitor photodiode power limit in mW. When constant MDP mode is used, the output level is limited only by the LIM Ix value.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:LIMit:V CHAPTER 4 FRONT PANEL REMOTE The LASer:LIMit:V command sets the LASER compliance voltage limit value. Syntax Diagram : Parameters Notes Examples LAS : LIM : V An that represents the LASER limit voltage, in volts. The voltage limit setting is useful for laser protection.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:MDI FRONT PANEL REMOTE The LASer:MDI command sets the value of the optical power setpoint, in µA, if the CALMD (CAL PD) responsivity is 0. Syntax Diagram MDI : : LAS IPD Parameters Notes Examples An that represents the photodiode feedback current, in µA. If the CALMD (CAL PD) parameter is not set to 0, the LAS:MDI value will not be used.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:MDLN CHAPTER 4 FRONT PANEL REMOTE The LASer:MDLN command enables or disables (turns off) the front panel modulation input (BNC). Syntax Diagram : Parameters Notes Examples LAS : MDLN An - where 1=on, 0=off. After turning the modulation off, it will remain off until turned back on via this command or by resetting the instrument.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:MDP FRONT PANEL REMOTE The LASer:MDP command sets the value of the optical power setpoint in mW if the CALMD (CAL PD) responsivity is greater than 0. Syntax Diagram MDP : : LAS P Parameters Notes Examples An that represents the photodiode feedback power in mW. If the CALMD (CAL PD) parameter is set to 0, the LAS:MDP value will not be used.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:MODE? CHAPTER 4 FRONT PANEL REMOTE The LASer:MODE? query returns the selected laser control mode. : Notes Examples : LAS ? MODE IHBW mode is the same as I mode (low bandwidth), except that the output low bandpass filter is disabled in IHBW mode. "LAS:MODE?" -response: ILBW, means that constant I (current) mode is in effect for the laser output.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:MODE:ILBW FRONT PANEL REMOTE The LASer:MODE:ILBW command selects laser constant current mode. I : LAS : MODE : ILBW Parameters Notes Examples None Constant I mode (low bandwidth) enables the output low bandpass filter. "LAS:MODE:ILBW" -action: sets the laser output for constant I mode (low bandwidth). LASer:MODE:MDP FRONT PANEL REMOTE The LASer:MODE:MDP command selects laser constant power mode.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:OUTput CHAPTER 4 FRONT PANEL REMOTE The LASer:OUTput command turns the laser output on or off. : Parameters Notes Examples : LAS OUT An ; 1=on, 0=off. There is a two-second delay after the output is turned on before the output shorting relay is opened. Following this, the output current ramps up to the current setpoint slowly to protect the laser.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:RANge FRONT PANEL REMOTE The LASer:RANge command selects the laser's drive current output range. : Parameters Notes Examples LAS : RAN An that represents the laser current output range. 2 = 2000 mA, and 4= 4000 mA range This range setting effects the Laser Drive Current output current range only. The Laser Drive Current output should be “off” when this command is issued.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:SET:LDI? CHAPTER 4 FRONT PANEL REMOTE The LASer:SET:LDI? query returns the constant I value that is used for both output ranges and both bandwidths. : : LAS Examples ? I LDI Notes : SET - where the response is the constant I setpoint value, in mA. In local operation, the constant I setpoint is read by selecting I or IHBW mode, then pressing and holding down the SELECT switch in the DISPLAY area of the front panel.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference "LAS:Set:MDI?" -response: 100.0 means the laser monitor photodiode current is setpoint is 100 µA, for use in constant P mode with CALMD=0. LASer:SET:MDP? FRONT PANEL REMOTE The LASer:SET:MDP? query returns the laser monitor photodiode power setpoint value (when CALMD [CAL PD] is not zero), in mW. : : LAS SET P MDP Notes Examples : ? - where the response is the constand PPD setpoint, in mW.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:STEP? 4 CHAPTER FRONT PANEL REMOTE The LASer:STEP? query is used to read back the LASer STEP value. This value is used to increment or decrement the selected laser control mode setpoint by the given amount when used with the LASer:INC or LASer:DEC command. : Examples LAS : STEP ? - where the response is an integer value. "Las:Mode:LDI; Las:Step?" -response: 1 means the step size is 0.1 mA, since Const I mode is in effect.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference LASer:TOLerance? FRONT PANEL REMOTE The LASer:TOLerance? query allows the programmer to determine how the LASER current tolerance is set. : Notes Examples LAS : TOL ? - where the response consists of two values, the first is the current tolerance in mA and the second is the time window, in seconds.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference MESsage? CHAPTER 4 FRONT PANEL REMOTE The MESsage? query returns the previously stored message. This message will always be 16 bytes long and enclosed in quotes. The message is entered via the MESsage command. : Notes Examples MES ? - where the response is a 16-byte long character string. The response data will be a 16-byte long string. If there is no previously stored message, the response will be " ", all spaces.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference "rad hex; *ESR?" -action: the hexadecimal radix is selected; -response: #H80, means power-on was detected. RADix? FRONT PANEL REMOTE The RADix? query allows the programmer to determine that radix type for status, condition, and event query response data is currently selected. Decimal, binary, octal, and hexadecimal are allowed.
COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference TERM? CHAPTER 4 FRONT PANEL REMOTE The TERM? query allows the programmer to determine whether the default (IEEE488.2 standard) terminator has been altered to include a carriage return. : Notes Examples TERM ? - where the response is 0 or 1. An altered terminator will be in the form <^END>. This termination will be sent with all output until the "TERM 0" command is sent, or the LDX-3232 is powered off.
CHAPTER 4 COMMAND REFERENCE LDX-3232 Device-Dependent Command Reference TIMER? FRONT PANEL REMOTE The TIMER? query allows the programmer to determine how much time has passed since the last TIMER? query was issued. : Notes Examples 82 LDX-3232 TIMER ? - where the response is character data that represents hours:minutes:seconds. Each time the TIMER? query is issued, the timer is reset to 0 and the elapsed time since the last TIMER? query is returned.
FU N C T I O N S A N D FE A T U R E S Saving and Recalling from the Front Panel CHAPTER CHAPTER 5 5 FUNCTIONS AND FEATURES This chapter introduces you to the LDX-3232 High Compliance Current Source functions and operating features such as event triggering, analog modulation of laser injection current, and Save and Recall.
CHAPTER 5 FU N C T I O N S A N D FE A T U R E S Saving and Recalling Under Remote Operation To recall a previously saved instrument setup, press the SELECT switch until the RECALL indicator led becomes lit. The instrument will display a RECALL "bin" number on the display. If you desire to change the RECALL bin, press and hold the SET switch and rotate the adjust knob until the desired bin number is displayed. Releasing the SET switch completes the RECALL operation.
FU N C T I O N S A N D FE A T U R E S Using the LDX-3232 Current Source’s Trigger Function CHAPTER 5 Using the LDX-3232 Current Source’s Trigger Function For applications where you need to synchronously initiate a measurement task from a remote instrument with the LDX-3232 Current Source, the Current Source offers a trigger output signal. The TTL pulse is initiated with any remote change in setpoint of the laser current source.
CHAPTER 5 FU N C T I O N S A N D FE A T U R E S Using the LDX-3232 Current Sources’s BNC Interlock Connection Using the LDX-3232 Current Sources’s BNC Interlock Connection The LDX-3232 BNC interlock connection is designed to allow an external emergency input signal to turn the current output off. The BNC interlock is TTL compatible and configured to be normally closed (as opposed to the DB-9 interlock connection, that is normally open).
FU N C T I O N S A N D FE A T U R E S Modulating the Laser Current Source CHAPTER 5 Setting up the Current Source for a modulated laser injection current is easy. The (MOD) EXTERNAL connector (BNC) on the front panel is the input for the modulated signal. Connect a modulating voltage signal from a standard function generator, for example, to this connector. The modulation port input impedance is 1 kΩ. The transfer function for the low and high current ranges of the LDX-3232 are 200 mA/V and 400 mA/V.
CHAPTER 5 FU N C T I O N S A N D FE A T U R E S Modulating the Laser Current Source To disable the output, press the OUTPUT push button again. When the LDX-3232 current output is off, an internal short is placed across the output. This short will prevent the modulation signal from reaching the LED in our example experiment. Thus, it is safe to disconnect the test device (LED) when the LDX-3232's output is off, regardless of the presence of the modulation signal.
CALIBRATION AND TROUBLESHOOTING Calibration Overview CHAPTER CHAPTER 6 6 CALIBRATION AND TROUBLESHOOTING This chapter describes calibration of your LDX-3232 Series Current Source. Descriptions of the required test instruments, calibration conditions, and the detailed procedures for calibration of the instrument's Laser Diode Current Source are included. A troubleshooting guide is also offered for some of the more common failure symptoms.
CHAPTER 6 CALIBRATION AND TR OUBLESHOOTING Recommended Equipment Finally, the LDX-3232 Current Source should be allowed to warm up for at least one hour before calibration. Recommended Equipment Recommended test equipment for calibrating the LDX-3232 Current Source is listed in Table 6.1. Equipment other than that shown in the table may be used if the specifications meet or exceed those listed. Table 6.
CALIBRATION AND TROUBLESHOOTING Local Calibration of the LDX-3232 Current Source CHAPTER 6 9-Pin D-Sub LD C athode (5) LD Anode (9) R4 1M PD C athode + (6) PD Anode - (7) Voltm eter A R2 100 R1 49 V R3 U 1 TIL117 6 1 5 Ipd C urrent Am m eter 2 4 3 CA LIB RATIO N CIRCUIT Figure 6.1 IPD Calibration Circuit Local Calibration of the LDX-3232 Current Source There are three calibration adjustments required for the LASER current source of the LDX-3232 Current Source.
CHAPTER 6 CALIBRATION AND TR OUBLESHOOTING Local Calibration of the LDX-3232 Current Source a. Measure and record the resistance of a 1Ω, 20 W resistor (A 4-wire [Kelvin] resistance measurement is recommended.) Connect the load resistor across the LASER output terminals (Laser Anode and Laser Cathode) on the 9 pin connector of the rear panel. b. Connect the calibrated DMM across the load resistor. Configure the multimeter to measure voltage in volts.
CALIBRATION AND TROUBLESHOOTING Local Calibration of the LDX-3232 Current Source CHAPTER 6 LDX-3232 Series Current Source then automatically calibrates the LASER feedback circuits. Configure the Current Source in the following manner for the Laser Current Source calibration: Function State MODE P (constant power) CAL PD set equal to zero CURRENT LIMIT 90% of FS (full scale of range) IPD SETPOINT 80% of FS a.
CHAPTER 6 CALIBRATION AND TR OUBLESHOOTING Local Calibration of the LDX-3232 Current Source g. Release the (PARAMETER) SET switch to accept the second calibration point. After the (PARAMETER) SET switch is released, the LDX-3232 Series Current Source will calculate the calibration constants and store them to nonvolatile memory. Laser Forward Voltage Measurement Calibration The following procedure is for calibrating the LASER voltage measurement.
CALIBRATION AND TROUBLESHOOTING Remote Calibration of the LDX-3232 Current Source CHAPTER 6 Remote Calibration of the LDX-3232 Current Source The LDX-3232 Current Sources can be calibrated remotely via the GPIB Interface. All of the required calibration commands are listed in Table 4.1 in Chapter 4. The procedures below are general guidelines for writing a program to calibrate your instrument.
CHAPTER 6 CALIBRATION AND TR OUBLESHOOTING Remote Calibration of the LDX-3232 Current Source a. Measure and record the resistance of a 1 Ω, 20 W resistor. (A 4-wire [Kelvin] resistance measurement is recommended.) Connect the load resistor across the LASER output terminals (Laser Anode and Laser Cathode) on the 9 pin connector of the rear panel. b. Connect the calibrated DMM across the load resistor. Configure the multimeter to measure voltage in volts.
CALIBRATION AND TROUBLESHOOTING Remote Calibration of the LDX-3232 Current Source CHAPTER 6 Configure the current source in the following manner for the laser current source calibration: 04_06 Function State GPIB COMMAND LASER MODE I (constant current low bandwidth) LAS:MODE:ILBW RANGE Low (lowest per instrument model) LAS:RAN x LIMIT 90% of FS (full scale of range) LAS:LIM:Ix IPD SETPOINT 80% of FS LAS:LDI a.
CHAPTER 6 CALIBRATION AND TR OUBLESHOOTING Remote Calibration of the LDX-3232 Current Source Laser Forward Voltage Measurement Calibration The following procedure is for calibrating the LASER voltage measurement.
CALIBRATION AND TROUBLESHOOTING Troubleshooting Guide 6 CHAPTER Troubleshooting Guide This section is a guide to troubleshooting the LDX-3232 Current Sources. Some of the more common symptoms are listed here, and the appropriate troubleshooting actions are given. We recommend that the user start at the beginning of this guide. Read the symptom descriptions, and follow the steps for the corrective actions that apply.
CHAPTER 100 LDX-3232 6 CALIBRATION AND TR OUBLESHOOTING Troubleshooting Guide Symptom Corrective Actions Unable to adjust output Check the I LIMIT parameter for the output range in use, see that it is set above 0 mA. Power mode operation has high output current, but little or no power measured Check back panel PD BIAS; if set too low, may act as an open feedback loop; if in doubt, set the PD BIAS to mid range (2.5 V) Output exceeds power limit The “power limit” is not a hardware limit.
CALIBRATION AND TROUBLESHOOTING Error Messages CHAPTER 6 Error Messages In the event of a hardware error condition, error messages will be displayed on the display. In most cases, the error message will appear for three seconds. In some cases the error code display will remain until the user changes display modes. In the case of multiple error messages, the display may sequentially show each message for three seconds. In addition to the hardware errors, GPIB errors may be read via the ERR? query.
CHAPTER 102 LDX-3232 6 CALIBRATION AND TR OUBLESHOOTING Error Messages Error Code Explanation E-203 Security violation, command is not available without clearance E-205 is not a Boolean value or word E-207 will not convert to an unsigned 16-bit value E-209 will not convert to an unsigned 32-bit value E-210 will not convert to a floating point value E-211 will not convert to a character value E-213 i
