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Lightwave Communications LDX-3232 manual Calibration and Troubleshooting, Calibration Overview

Models: LDX-3232

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CA LI BRATION AND TR OUBLESHOOTING

Calibration Overview

C H A P T E R 6

C H A P T E R 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. This chapter is divided into three major sections, local (front panel) calibration, remote (through the GPIB Interface) calibration, and a troubleshooting guide.

Calibration Overview

There are several calibrations to be performed to completely calibrate your LDX-3232 Current Source. The Laser Diode Current Source calibration consists of calibrating the current source in both ranges and both modes (low and high bandwidth), calibrating the photodiode monitor feedback ammeter and finally the forward voltage measurement. The current limits are calibrated internally by the instrument as part of the calibration process.

Your LDX-3232 Current Source can be calibrated with the case closed. It should be calibrated every 12 months or whenever performance verification indicates that calibration is necessary, such as differences between setpoint and measurement display values that exceed the accuracy specification. Calibrate the instrument under laboratory conditions. We recommend calibration at 23°C ± 1.0°C. When necessary, however, the LDX-3232 Current Source may be calibrated at its intended use temperature if this is within the specified operating temperature range of 0 to 40°C.

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LDX-3232

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Lightwave Communications LDX-3232 manual Calibration and Troubleshooting, Calibration Overview

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 General Safety Considerations Safety Information and the Manual Safety Marking Symbols Safety 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 Product Overview Introduction and Specifications AC Line Power Requirements Installing Your LDX-3232 High Compliance Current SourceInitial Inspection Grounding Requirements Tilt-Foot Adjustment Gpib ConnectorGpib Address Operating the LDX-3232 Precision Current Source LDX-3232 Front View Maintenance Specifications Type Pulse Width Delay TTL13 µs 12 ms Description Model Number Available Options and Accessories Power On Sequence Applying Power to Your LDX-3232 Power On State Connecting to the Laser Common Laser Cathode Photodiode Anode Interlock Connections Back Panel LD Connector 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 Entering Photodiode Responsivity Values Operating a Laser in Constant Power P Mode Method to calculate the responsivity is suggested below LDX-3232 Error Indicators Error Indicators Error Indicators LDX-3232 Changing the Gpib Address Reading the Gpib Address LDX-3232 Current Source Command Set Command SyntaxChanging Operation from Local to Remote OFF OLD NEW True False SET Reset LASLDI? LDX-3232 Command Path Structure Command Paths IEEE488.2 Command Commands LDX-3232 Frequently Used Commands NoneLIM Status Reporting Event and Condition RegistersOperation Complete Definition LDX-3232 Status Reporting Schematic Diagram Output Off Register Disabled 10 N/A Enabled 11 N/A 12 N/A 13 N/A 14 N/A 15 N/A LASerENABleOUTOFF nrf LASerENABleOUTOFF? Error Messages Command Timing and Completion Response Message Error Code Classifications Mode Commands Used to create a delay in the execution of furtherUsed to enter the laser current calibration mode Used to enter the laser voltage calibration mode Enables Laser display to show parameter values Returns status of photodiode monitor power displaySets the enable register for Laser conditions Returns the value of the LAS conditions enable register Used to set the constant optical power setpoint, if Used to return the optical power from monitorUsed to enable/disable the front panel modulation input Or P optical power Powered up Returns the status of the Term commandReturns the elapsed time since the timer was last reset Used to return the Laser setpoint tolerance value Command Description Format LDX-3232 Device-Dependent Commands Delay LDX-3232 Device-Dependent Command Reference ERRors? LASerCALMDCalmd LAS Calpd LASerCALMD? Responsivity CAL PD parameter setting Syntax Diagram Selected. This procedure is outlined in Chapter LASerCALLDICalibration for that bandwidth LASerCALLDV LASerCALLDI?LDI LAS CAL LAS CAL LDV True measured value. This procedure is outlined in Chapter LASerCALLDV?LASerCALMDI LASerCOND? LASerCALMDI?MDI LAS CAL IPD LASerDEC LASerDISplay? LASerDISplayLAS DIS LASDIS? LASerDISplayLDI? LASerDISplayLDILasdisldi LDI LASerDISplayLDV Voltage measurement Syntax DiagramLASerDISplayLDV? LASDISLDV? LASerDISplayMDI? LASerDISplayMDILAS DIS MDI LAS DIS IPD LASerDISplayMDP? LASerDISplayMDPPPD LAS DIS MDP LASerDISplaySET LASerDISplayPARAMLAS DIS Param LAS DIS SET LASerENABleCOND LASerDISplaySET?LASDISPLAYSET? LASerENABleCOND? BitLAS Enab Cond An nrf value whose sum represents the bits that are enabled LASerENABleEVEntAction enables the Laser status event register so that Lasenabevent LAS Enab EVE LASerENABleEVEnt? LASerENABleOUTOFF LAS Enab Outoff LASerENABleOUTOFF? Command while the condition status is constantly changing LASerENABleEVEnt commandLASerEVEnt? LAS EVE Function for the Laser output LASerINC LASerLDI This measurement is updated approximately once every 600 msLASerLDI? LAS LDI LASerLDV? LASerLDVFor LDV calibration LAS LDV LASerLIMitI2? LASerLIMitI2Limit in use depends on the Laser output range selection LAS LIM LASerLIMitI4 Displayed, and then releasing the SET switchLASerLIMitI4? LASLIMI4? LASerLIMitMDP LASerLIMitMDP?MDP LAS LIM LASerLIMitV? LASerLIMitV LASerMDI? LASerMDIMDI LAS IPD MDP P PD setpoint would be used LASerMDLN LASerMDLN?LAS Mdln LASerMDP LASerMDP?MDP LAS LAS Mode Ihbw LAS ModeLASerMODE? LASerMODEIHBW LASerMODEILBW LAS Mode MDPLASerMODEMDP Lasmodeilbw LASerOUTput LASerOUTput?LAS OUT LASerRANge? LASerRANgeLAS RAN LASRAN? 30 µA, for use in constant P mode with Calpd = Where the response is the constant I setpoint value, in mALASerSETLDI? LASerSETMDI? LASerSETMDP? Where the response is the constand PPD setpoint, in mWLASerSTEP 100 µA LASerSTEP? LASerTOLerance commandLASerTOLerance LAS TOL MESsage LASerTOLerance?Second is the time window, in seconds MES RADix MESsage? RADix? Term 0 command is sent or the LDX-3232 is powered offRAD Means hexadecimal, and OCT means octal LDX-3232 was last powered up Time clock is independent of the Timer clockTime Timer Since the last TIMER? query was issuedLast TIMER? query is returned Seconds since the last TIMER? query was issued Saving and Recalling from the Front Panel Functions and Features Saving and Recalling Under Remote Operation Using the Laser Compliance Voltage Adjustment LDX-3232 Rear Panel Using the LDX-3232 Current Source’s Trigger Function BNC Interlock Usage Example Modulating the Laser Current Source Modulating the Laser Current Source Functions and Features Calibration Overview Calibration and Troubleshooting Description Manufacturer/Model Specification Recommended EquipmentDMM Current Source Calibration Local Calibration of the LDX-3232 Current SourceRange Current Limit IPD Current Calibration CAL PD Constant powerSet equal to zero IPD Setpoint Laser Forward Voltage Measurement Calibration Laser Mode2000 mA 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 General Troubleshooting GuideEEPROM, Lllll will be displayed on the display the laser Current source must be recalibrated Command Feature can be defeated via the Lasenableoutoff 101 Response Message