Lightwave Communications LDX-3232 manual Connecting to the Laser, Power On State

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C H A P T E R 2

O P E R A T I O N

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. See Chapter 3 for a list of error codes and actions to take when your instrument indicates these errors.

Table 2.1 LDX-3232 Default Settings

GPIB mode in LOCAL via front panel, or in REMOTE via GPIB

PARAMETERS not selected

CAL PD = 0 µA / mW

LIM I (high range) = 1000 mA

LIM I (low range) = 500 mA

LIM V = 15 volts

LIM P = 5000 mW

Output off

DISPLAY enabled, in I mode

Constant I, low bandwidth mode selected

I setpoint = 0 mA

IPD setpoint = 0 µA

PPD setpoint = 0 mW

RECALL BIN number = 0

Connecting to the Laser

When connecting your laser to the LDX-3232, we recommend that the instrument be powered up with the output off. In this condition, a low impedance shunt is active across the output terminals. When disconnecting devices, it is only necessary to turn the current source output off.

It is also recommended that the connections to the LDX-3232 output be made using twisted wire pairs with an earth-grounded shield (see Figures 2.1 - 2.4). The output terminals of the instrument are left floating relative to earth ground to suppress AC power-on/power-off transients that may occur through an earth- ground path. If the output circuit is earth-grounded at some point (such as through the laser package and mount), the user must be careful to avoid multiple earth

10 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 Model Number Serial Number End-User Name Company Phone Fax Comments, Suggestions, and ProblemsDescription of the problem 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 13 µs 12 ms Type Pulse Width DelayTTL 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 ConnectionsGrounding Considerations Setting the PD BiasPhotodiode Connections Display Operating a Laser in Constant Current I ModeFront Panel Operation 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 AddressChanging Operation from Local to Remote LDX-3232 Current Source Command SetCommand Syntax OFF OLD NEW True False SET Reset LASLDI? Command Paths LDX-3232 Command Path StructureIEEE488.2 Command Commands LIM LDX-3232 Frequently Used CommandsNone Operation Complete Definition Status ReportingEvent and Condition Registers 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 DelayCalmd LAS Calpd ERRors?LASerCALMD Responsivity CAL PD parameter setting Syntax Diagram LASerCALMD?Calibration for that bandwidth Selected. This procedure is outlined in ChapterLASerCALLDI LDI LAS CAL LASerCALLDI?LASerCALLDV LAS CAL LDVLASerCALMDI True measured value. This procedure is outlined in ChapterLASerCALLDV? 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 SETLASDISPLAYSET? LASerENABleCONDLASerDISplaySET? LAS Enab Cond LASerENABleCOND?Bit 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?MDP LAS LIM LASerLIMitMDPLASerLIMitMDP? LASerLIMitV LASerLIMitV?MDI LAS IPD LASerMDILASerMDI? MDP P PD setpoint would be usedLAS Mdln LASerMDLNLASerMDLN? MDP LAS LASerMDPLASerMDP? LASerMODE? LAS ModeLAS Mode Ihbw LASerMODEIHBWLASerMODEMDP LAS Mode MDPLASerMODEILBW LasmodeilbwLAS OUT LASerOUTputLASerOUTput? 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 LDX-3232 was last powered upTime clock is independent of the Timer clock 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 ExampleModulating the Laser Current Source Functions and Features Calibration and Troubleshooting Calibration OverviewDMM Description Manufacturer/Model SpecificationRecommended Equipment 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 rangeLimit Gpib CommandRemote Calibration of the LDX-3232 Current Source 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