Lightwave Communications LDX-3232 manual Saving and Recalling Under Remote Operation

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C H A P T E R 5

FUNCTIONS AND FEATURES

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. The instrument is restarted and the front panel parameters are reconfigured to the new parameters saved under that bin number.

The factory default values for front panel parameters may be restored by recalling "bin" zero (0). See Table 2.1 for the default settings.

Saving and Recalling Under Remote Operation

For saving under remote operation, use the command *SAV x, where x is the desired "bin" number (1-10). For a recall under remote operation, use the command *RCL x, where x is the desired "bin" number (0 - 10).

Using the Laser Compliance Voltage Adjustment

For applications where you need to have critical protection of the laser, we recommend the following. Using a 1 Ω resistor or other non-critical load, set the LASER voltage limit as described in Chapter 2.

Then with the LASER output on, slowly increase the LASER current and watch the LASER voltage measurement. Press the (DISPLAY) SELECT push button to see the voltage. At about 0.25 V below the LASER voltage limit value, the VOLTAGE LIMIT warning indicator will become lit on the display. Continue to adjust the current upwards until the voltage limit is reached and the output is shut off. Record the voltage at that the LASER output shuts off. It should be within the specification of the LASER voltage limit accuracy. However, there is typically some offset error. For example, if the LASER voltage limit is set to 5.0 V, the actual voltage where it shuts off may be 4.9 V. This error term of 0.1 V should be considered when setting the LASER compliance voltage limit.

The closer the LASER voltage limit shut off point is to the operating voltage of your laser, the faster the circuit will work in the event of an open circuit. Some experimentation may be necessary for optimum results.

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Contents User’s Guide Page Table of Contents Remote Operation Command Reference Iv LDX-3232 List of Figures Vi LDX-3232 List of Tables Viii LDX-3232 Safety Information and the Manual General Safety ConsiderationsSafety Symbols Safety Marking SymbolsWarranty Claims for Shipping Damage Description of the problem Comments, Suggestions, and ProblemsModel Number Serial Number End-User Name Company Phone Fax Xiv LDX-3232 Introduction and Specifications Product OverviewInstalling Your LDX-3232 High Compliance Current Source AC Line Power RequirementsInitial Inspection Grounding RequirementsGpib Connector Tilt-Foot AdjustmentGpib Address Operating the LDX-3232 Precision Current SourceLDX-3232 Front View Maintenance Specifications TTL Type Pulse Width Delay13 µs 12 ms Available Options and Accessories Description Model NumberApplying Power to Your LDX-3232 Power On SequenceConnecting to the Laser Power On StateCommon Laser Cathode Photodiode Anode Back Panel LD Connector Interlock ConnectionsPhotodiode Connections Setting the PD BiasGrounding Considerations Front Panel Operation Operating a Laser in Constant Current I ModeDisplay Setting Up the Precision Current Source E R a T I O N Operating a Laser in Constant Power P Mode Entering Photodiode Responsivity ValuesMethod to calculate the responsivity is suggested below Error Indicators LDX-3232 Error IndicatorsError Indicators LDX-3232 Reading the Gpib Address Changing the Gpib AddressCommand Syntax LDX-3232 Current Source Command SetChanging Operation from Local to Remote OFF OLD NEW True False SET Reset LASLDI? Command Paths LDX-3232 Command Path StructureIEEE488.2 Command Commands None LDX-3232 Frequently Used CommandsLIM Event and Condition Registers Status ReportingOperation Complete Definition LDX-3232 Status Reporting Schematic Diagram Disabled 10 N/A Enabled 11 N/A 12 N/A 13 N/A 14 N/A 15 N/A Output Off RegisterLASerENABleOUTOFF nrf LASerENABleOUTOFF? Command Timing and Completion Error MessagesError Code Classifications Response MessageMode Used to create a delay in the execution of further CommandsUsed to enter the laser current calibration mode Used to enter the laser voltage calibration modeReturns status of photodiode monitor power display Enables Laser display to show parameter valuesSets the enable register for Laser conditions Returns the value of the LAS conditions enable registerUsed to return the optical power from monitor Used to set the constant optical power setpoint, ifUsed to enable/disable the front panel modulation input Or P optical powerReturns the status of the Term command Powered upReturns the elapsed time since the timer was last reset Used to return the Laser setpoint tolerance valueLDX-3232 Device-Dependent Commands Command Description FormatLDX-3232 Device-Dependent Command Reference DelayLASerCALMD ERRors?Calmd LAS Calpd Responsivity CAL PD parameter setting Syntax Diagram LASerCALMD?LASerCALLDI Selected. This procedure is outlined in ChapterCalibration for that bandwidth LASerCALLDI? LASerCALLDVLDI LAS CAL LAS CAL LDVLASerCALLDV? True measured value. This procedure is outlined in ChapterLASerCALMDI LASerCALMDI? LASerCOND?MDI LAS CAL IPDLASerDEC LASerDISplay LASerDISplay?LAS DIS LASDIS?LASerDISplayLDI LASerDISplayLDI?Lasdisldi LDIVoltage measurement Syntax Diagram LASerDISplayLDVLASerDISplayLDV? LASDISLDV?LASerDISplayMDI LASerDISplayMDI?LAS DIS MDI LAS DIS IPDLASerDISplayMDP LASerDISplayMDP?PPD LAS DIS MDPLASerDISplayPARAM LASerDISplaySETLAS DIS Param LAS DIS SETLASerDISplaySET? LASerENABleCONDLASDISPLAYSET? Bit LASerENABleCOND?LAS Enab Cond LASerENABleEVEnt An nrf value whose sum represents the bits that are enabledAction enables the Laser status event register so that LasenabeventLASerENABleEVEnt? LAS Enab EVELASerENABleOUTOFF LASerENABleOUTOFF? LAS Enab OutoffLASerENABleEVEnt command Command while the condition status is constantly changingLASerEVEnt? LAS EVELASerINC Function for the Laser outputThis measurement is updated approximately once every 600 ms LASerLDILASerLDI? LAS LDILASerLDV LASerLDV?For LDV calibration LAS LDVLASerLIMitI2 LASerLIMitI2?Limit in use depends on the Laser output range selection LAS LIMDisplayed, and then releasing the SET switch LASerLIMitI4LASerLIMitI4? LASLIMI4?LASerLIMitMDP? LASerLIMitMDPMDP LAS LIM LASerLIMitV LASerLIMitV?LASerMDI LASerMDI?MDI LAS IPD MDP P PD setpoint would be usedLASerMDLN? LASerMDLNLAS Mdln LASerMDP? LASerMDPMDP LAS LAS Mode LAS Mode IhbwLASerMODE? LASerMODEIHBWLAS Mode MDP LASerMODEILBWLASerMODEMDP LasmodeilbwLASerOUTput? LASerOUTputLAS OUT LASerRANge LASerRANge?LAS RAN LASRAN?Where the response is the constant I setpoint value, in mA 30 µA, for use in constant P mode with Calpd =LASerSETLDI? LASerSETMDI?Where the response is the constand PPD setpoint, in mW LASerSETMDP?LASerSTEP 100 µALASerTOLerance command LASerSTEP?LASerTOLerance LAS TOLLASerTOLerance? MESsageSecond is the time window, in seconds MESMESsage? RADixTerm 0 command is sent or the LDX-3232 is powered off RADix?RAD Means hexadecimal, and OCT means octalTime clock is independent of the Timer clock LDX-3232 was last powered upTime Since the last TIMER? query was issued TimerLast TIMER? query is returned Seconds since the last TIMER? query was issuedFunctions and Features Saving and Recalling from the Front PanelUsing the Laser Compliance Voltage Adjustment Saving and Recalling Under Remote OperationUsing the LDX-3232 Current Source’s Trigger Function LDX-3232 Rear PanelModulating the Laser Current Source BNC Interlock Usage ExampleModulating the Laser Current Source Functions and Features Calibration and Troubleshooting Calibration OverviewRecommended Equipment Description Manufacturer/Model SpecificationDMM Local Calibration of the LDX-3232 Current Source Current Source CalibrationRange Current LimitIPD Current Calibration Constant power CAL PDSet equal to zero IPD SetpointLaser Mode Laser Forward Voltage Measurement Calibration2000 mA Set to FS full scale of rangeRemote Calibration of the LDX-3232 Current Source Gpib CommandLimit Lasldi nrf value command IPD Setpoint Function State Gpib Command Troubleshooting Guide GeneralEEPROM, Lllll will be displayed on the display the laser Current source must be recalibratedFeature can be defeated via the Lasenableoutoff Command101 Response Message