Lightwave Communications LDX-3232 manual Recommended Equipment, Dmm

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C H A P T E R 6

CALIBRATION AND TR OU BLESHOOTING

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 6.1 Recommended Test Equipment

Description

Manufacturer/Model

Specification

DMM

HP 3457A

DC Amps (@ 1.0 A): ±0.02%

 

 

Resistance (@ 10 Ω): ±0.02%

 

 

0.1 µA or 0.1 mV resolution

 

 

 

It will be necessary to connect various loads and circuits to the outputs of each current source for the calibration procedure. A schematic is shown in Figure 6.1 for the photodiode calibration circuit with the required components listed in Table 6.2. Also, the devices required for other calibration loads are listed in Table 6.2.

Table 6.2 Required Calibration Components

Laser Current Source Calibration

Current Source Calibration, all models

10

Ω, 20 W resistor, low TCR

 

 

 

Voltage Measurement Calibration

15

Ω, 5 W resistor, low TCR

 

 

 

PD Monitor Calibration (See Schematic in Figure 6.1)

 

 

 

 

PD Calibration Circuit

 

 

R1

 

49 Ω resistor, 1%, 1/4 W

R2

 

100 Ω resistor, 1%, 1/4 W

R4

 

1.0 MΩ resistor, 1%, 1/4 W

R3

 

5 Ω, 1%, 10W

U1

 

TIL 117 opto isolator

 

 

 

90 LDX-3232

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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 OverviewInitial Inspection Installing Your LDX-3232 High Compliance Current SourceAC Line Power Requirements Grounding RequirementsGpib Address Gpib ConnectorTilt-Foot Adjustment 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 enter the laser current calibration mode Used to create a delay in the execution of furtherCommands Used to enter the laser voltage calibration modeSets 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 registerUsed 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 powerReturns the elapsed time since the timer was last reset Returns the status of the Term commandPowered up 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 LDI LAS CAL LASerCALLDI?LASerCALLDV LAS CAL LDVLASerCALLDV? True measured value. This procedure is outlined in ChapterLASerCALMDI MDI LASerCALMDI?LASerCOND? LAS CAL IPDLASerDEC LAS DIS LASerDISplayLASerDISplay? LASDIS?Lasdisldi LASerDISplayLDILASerDISplayLDI? LDILASerDISplayLDV? Voltage measurement Syntax DiagramLASerDISplayLDV LASDISLDV?LAS DIS MDI LASerDISplayMDILASerDISplayMDI? LAS DIS IPDPPD LASerDISplayMDPLASerDISplayMDP? LAS DIS MDPLAS DIS Param LASerDISplayPARAMLASerDISplaySET LAS DIS SETLASerDISplaySET? LASerENABleCONDLASDISPLAYSET? Bit LASerENABleCOND?LAS Enab Cond Action enables the Laser status event register so that LASerENABleEVEntAn nrf value whose sum represents the bits that are enabled LasenabeventLASerENABleEVEnt? LAS Enab EVELASerENABleOUTOFF LASerENABleOUTOFF? LAS Enab OutoffLASerEVEnt? LASerENABleEVEnt commandCommand while the condition status is constantly changing LAS EVELASerINC Function for the Laser outputLASerLDI? This measurement is updated approximately once every 600 msLASerLDI LAS LDIFor LDV calibration LASerLDVLASerLDV? LAS LDVLimit in use depends on the Laser output range selection LASerLIMitI2LASerLIMitI2? LAS LIMLASerLIMitI4? Displayed, and then releasing the SET switchLASerLIMitI4 LASLIMI4?LASerLIMitMDP? LASerLIMitMDPMDP LAS LIM LASerLIMitV LASerLIMitV?MDI LAS IPD LASerMDILASerMDI? MDP P PD setpoint would be usedLASerMDLN? LASerMDLNLAS Mdln LASerMDP? LASerMDPMDP LAS LASerMODE? LAS ModeLAS Mode Ihbw LASerMODEIHBWLASerMODEMDP LAS Mode MDPLASerMODEILBW LasmodeilbwLASerOUTput? LASerOUTputLAS 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 µALASerTOLerance LASerTOLerance commandLASerSTEP? LAS TOLSecond is the time window, in seconds LASerTOLerance?MESsage MESMESsage? RADixRAD Term 0 command is sent or the LDX-3232 is powered offRADix? Means hexadecimal, and OCT means octalTime clock is independent of the Timer clock LDX-3232 was last powered upTime Last TIMER? query is returned Since the last TIMER? query was issuedTimer 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 Example Modulating the Laser Current Source Functions and Features Calibration and Troubleshooting Calibration OverviewRecommended Equipment Description Manufacturer/Model SpecificationDMM Range Local Calibration of the LDX-3232 Current SourceCurrent Source Calibration Current LimitIPD Current Calibration Set equal to zero Constant powerCAL PD IPD Setpoint2000 mA Laser ModeLaser Forward Voltage Measurement Calibration 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 EEPROM, Lllll will be displayed on the display the laser Troubleshooting GuideGeneral Current source must be recalibratedFeature can be defeated via the Lasenableoutoff Command101 Response Message
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