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Lightwave Communications LDX-3232 manual Front Panel Operation, Display

Models: LDX-3232

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C H A P T E R 2

O P E R A T I O N

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. It will also display error codes that relate to LASER operation. Error indicators underneath the display indicate control errors and are explained in the section titled “ERROR INDICATORS”. All laser control parameters are displayed on this digital display with the appropriate annunciator illuminated.

Operating a Laser in Constant Current (I) Mode

Suppose you have an LDX-3232 and you want to run the instrument in Constant Current, low bandwidth mode, with a setpoint of 1500 mA and a current limit of 1750 mA. This particular mode uses a low-pass filter on the laser drive current output to significantly reduce noise. In this mode a modulation input of up to

10 kHz may be used via the front panel MOD EXTERNAL connector. Follow the instructions below in the sequence presented.

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Lightwave Communications LDX-3232 manual Front Panel Operation, Operating a Laser in Constant Current I Mode, Display

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 Considerations Safety Symbols Safety Marking Symbols Warranty Claims for Shipping Damage Comments, Suggestions, and Problems Description of the problemModel Number Serial Number End-User Name Company Phone Fax Xiv LDX-3232 Introduction and Specifications Product Overview Initial Inspection Installing Your LDX-3232 High Compliance Current SourceAC Line Power Requirements Grounding Requirements Gpib Address Gpib ConnectorTilt-Foot Adjustment Operating the LDX-3232 Precision Current Source LDX-3232 Front View Maintenance Specifications Type Pulse Width Delay TTL13 µs 12 ms Available Options and Accessories Description Model Number Applying Power to Your LDX-3232 Power On Sequence Connecting to the Laser Power On State Common Laser Cathode Photodiode Anode Back Panel LD Connector Interlock Connections Setting the PD Bias Photodiode ConnectionsGrounding Considerations Operating a Laser in Constant Current I Mode Front Panel OperationDisplay Setting Up the Precision Current Source E R a T I O N Operating a Laser in Constant Power P Mode Entering Photodiode Responsivity Values Method to calculate the responsivity is suggested below Error Indicators LDX-3232 Error Indicators Error Indicators LDX-3232 Reading the Gpib Address Changing the Gpib Address LDX-3232 Current Source Command Set Command SyntaxChanging Operation from Local to Remote OFF OLD NEW True False SET Reset LASLDI? Command Paths LDX-3232 Command Path Structure IEEE488.2 Command Commands LDX-3232 Frequently Used Commands NoneLIM Status Reporting Event and Condition RegistersOperation 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 Register LASerENABleOUTOFF nrf LASerENABleOUTOFF? Command Timing and Completion Error Messages Error Code Classifications Response Message Mode Used to enter the laser current calibration mode Used to create a delay in the execution of furtherCommands Used to enter the laser voltage calibration mode Sets the enable register for Laser conditions Returns status of photodiode monitor power displayEnables Laser display to show parameter values Returns the value of the LAS conditions enable register Used to enable/disable the front panel modulation input Used to return the optical power from monitorUsed to set the constant optical power setpoint, if Or P optical power Returns the elapsed time since the timer was last reset Returns the status of the Term commandPowered up Used to return the Laser setpoint tolerance value LDX-3232 Device-Dependent Commands Command Description Format LDX-3232 Device-Dependent Command Reference Delay ERRors? LASerCALMDCalmd LAS Calpd Responsivity CAL PD parameter setting Syntax Diagram LASerCALMD? Selected. This procedure is outlined in Chapter LASerCALLDICalibration for that bandwidth LDI LAS CAL LASerCALLDI?LASerCALLDV LAS CAL LDV True measured value. This procedure is outlined in Chapter LASerCALLDV?LASerCALMDI MDI LASerCALMDI?LASerCOND? LAS CAL IPD LASerDEC LAS DIS LASerDISplayLASerDISplay? LASDIS? Lasdisldi LASerDISplayLDILASerDISplayLDI? LDI LASerDISplayLDV? Voltage measurement Syntax DiagramLASerDISplayLDV LASDISLDV? LAS DIS MDI LASerDISplayMDILASerDISplayMDI? LAS DIS IPD PPD LASerDISplayMDPLASerDISplayMDP? LAS DIS MDP LAS DIS Param LASerDISplayPARAMLASerDISplaySET LAS DIS SET LASerENABleCOND LASerDISplaySET?LASDISPLAYSET? LASerENABleCOND? BitLAS Enab Cond Action enables the Laser status event register so that LASerENABleEVEntAn nrf value whose sum represents the bits that are enabled Lasenabevent LASerENABleEVEnt? LAS Enab EVE LASerENABleOUTOFF LASerENABleOUTOFF? LAS Enab Outoff LASerEVEnt? LASerENABleEVEnt commandCommand while the condition status is constantly changing LAS EVE LASerINC Function for the Laser output LASerLDI? This measurement is updated approximately once every 600 msLASerLDI LAS LDI For LDV calibration LASerLDVLASerLDV? LAS LDV Limit in use depends on the Laser output range selection LASerLIMitI2LASerLIMitI2? LAS LIM LASerLIMitI4? Displayed, and then releasing the SET switchLASerLIMitI4 LASLIMI4? LASerLIMitMDP LASerLIMitMDP?MDP LAS LIM LASerLIMitV LASerLIMitV? MDI LAS IPD LASerMDILASerMDI? MDP P PD setpoint would be used LASerMDLN LASerMDLN?LAS Mdln LASerMDP LASerMDP?MDP LAS LASerMODE? LAS ModeLAS Mode Ihbw LASerMODEIHBW LASerMODEMDP LAS Mode MDPLASerMODEILBW Lasmodeilbw LASerOUTput LASerOUTput?LAS OUT LAS RAN LASerRANgeLASerRANge? LASRAN? LASerSETLDI? Where the response is the constant I setpoint value, in mA30 µA, for use in constant P mode with Calpd = LASerSETMDI? LASerSTEP Where the response is the constand PPD setpoint, in mWLASerSETMDP? 100 µA LASerTOLerance LASerTOLerance commandLASerSTEP? LAS TOL Second is the time window, in seconds LASerTOLerance?MESsage MES MESsage? RADix RAD Term 0 command is sent or the LDX-3232 is powered offRADix? Means hexadecimal, and OCT means octal LDX-3232 was last powered up Time clock is independent of the Timer clockTime Last TIMER? query is returned Since the last TIMER? query was issuedTimer Seconds since the last TIMER? query was issued Functions and Features Saving and Recalling from the Front Panel Using the Laser Compliance Voltage Adjustment Saving and Recalling Under Remote Operation Using the LDX-3232 Current Source’s Trigger Function LDX-3232 Rear Panel Modulating the Laser Current Source BNC Interlock Usage Example Modulating the Laser Current Source Functions and Features Calibration and Troubleshooting Calibration Overview Description Manufacturer/Model Specification Recommended EquipmentDMM Range Local Calibration of the LDX-3232 Current SourceCurrent Source Calibration Current Limit IPD Current Calibration Set equal to zero Constant powerCAL PD IPD Setpoint 2000 mA Laser ModeLaser Forward Voltage Measurement Calibration Set to FS full scale of range Gpib Command Remote Calibration of the LDX-3232 Current SourceLimit Lasldi nrf value command IPD Setpoint Function State Gpib Command EEPROM, Lllll will be displayed on the display the laser Troubleshooting GuideGeneral Current source must be recalibrated Feature can be defeated via the Lasenableoutoff Command 101 Response Message