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Installing the LDC-3916330 Series Laser Diode Controller Module

1. 79 Laser Forward Voltage Measurement Calibration 80 Remote Calibration of the LDC 3916330 Dual Current Source Module 81 Laser Current Source Calibration 81 EDI Calibration ees RR Rene ES e E ar 81 IPD Current 1 83 Laser Forward Voltage Measurement Calibration 85 Troubleshooting Guide 87 09 07 LDC 3916330Series iii pee ens 7 LDC 3916330 Series Lightwave LIST OF FIGURES E EB L a B El El B L L El El Figure 2 1 Common Laser Cathode Photodiode Cathode 8 Figure 2 2 Common Laser Cathode Photodiode Anode 9 Figure 2 3 Common Laser Anode Photodiode Cathode 9 Figure 2 4 Common Laser Anode Photodiode Anode 9 Figure 2 5 Back Panel LD 10 Figure 3 1 LDC 3916 and LDC 3916330 Series Command Pal cS DOLUS eo sua ek dace S ades fe e REDE Eas 26 Figure 3 2 LDC 3916330 Series Condition Registers 29 Figure 3 3 LDC 3916330 Series Event Registers 30 Figure 3 4 LDC 3916330 Series Laser Diode Controller LASER Output Register 51 21 ke Re 32 Figure 5 1 lpp Calibration Circuit 76 09 07 LDC 39
2. The CAUTION heading explains hazards that could damage your instrument Lightwave LDC 3916330 Series 1 INTRODUCTION AND SPECIFICATIONS _ Product Overview The NOTES heading gives information to the user that may be beneficial in the use of the instrument and to the devices being tested Product Overview The LDC 3916330 Series Laser Diode Current Source Modules consist of two dual output current source modules and one single output current source module The LDC 3916332 and LDC 3916334 dual modules have two independent current sources with a maximum output current of 500 mA and 1 Amp respectively while the LDC 3916338 single module has a single current source with a maximum output current of 3 Amps Each current source provides a high stability low noise output with fully redundant hardware current limits and multiple laser protection features such as intermittent contact protection adjustable compliance voltage limit slow turn on and shorting circuits The LDC 3916330 Series modules can be used in the LDC 3916 sixteen channel mainframe the LDC 3908 eight channel mainframe and the LDC 3926 high power sixteen channel mainframe Installing the LDC 3916330 Series Laser Diode Controller Module Installation into LDC 3916 Laser Diode Controller Mainframe If you are receiving this new module for installation into a previously purchased LDC 3908 LDC 3916 or LDC 3926 mainframe follow the instructions below If your
3. LD Cathode 5 LD Anode 9 PD Cathode 6 PD Anode 7 CALIBRATION CIRCUIT Figure 5 1 lpp Calibration Circuit 76 7 LDC 3916330 Series Lightwave TROUBLESHOOTING Calibration Overview Table 5 3 Components for lpp Calibration Circuit COMPONENTS FOR PHOTODIODE CURRENT lpp CALIBRATION CIRCUIT R1 490 resistor 1 1 4W R2 1000 resistor 196 1 4W R4 1 0 resistor 1 1 4W R3 resistor 1 5W U1 TIL 117 opto isolator Battery 9V battery Connector 9 pin D sub male 09 07 LDC 3916330 Series 77 78 J TROUBLESHOOTING Local Local Calibration of the Laser Current Source Calibration of the Laser Current Source There are three calibration adjustments for each current source of the 3916330 Series Current Source Module They are calibration of the constant current LDI sou rce calibration of the constant light power lpp feedback circuit and calibration of the laser forward voltage LDV measurement Current Source Calibration The following procedure is for calibrating the laser current source The internal calibration procedure sets the current to two values You must enter the exact Las er Diode current that you measure at both of these points The internal procedure will then use this information to calibrate the current source 1 LDC 3916330 Series With the output off connect a 19 20 W resistor across t
4. Examples Laser1 CAL MDI action the selected module enters the Laser1 photodiode current calibration mode 09 07 LDC 3916330 Series 43 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn CAL MEAS C DEVICE DEPENDENT FRONT PANEL The LASERn CAL MEAS command is used to enter measured values during the selected module s laser calibration procedure white nrf space value Parameters nrf value which represents the measured value expected for the present Laser1 calibration state Notes See the Service Reference portion of this manual for compete calibration instructions Examples Laser1 CAL MEAS 4 95 action the module uses the value 4 95 for the required measurement value LASERn CAL STATus DEVICE DEPENDENT The LASERn CAL STATus query is to determine whether the unit is ready for a calibration value and whether it is in a laser calibration mode POP S Parameters None The response will be an nrf value 0 not ready for measurement 1 ready for measurement 2 calibration completed 3 calibration aborted Notes If the calibration is aborted the status value will remain 3 until the calibration is started again Examples LASER1 CAL STAT response 1 means the module is ready for a calibration measurement to be entered using the LASER1 CAL MEAS command LASER1 CAL STAT response 2 means the module has completed calibration LAser1
5. First read the system errors and module error summary with the ERR query This allows you to error check the LDC 3916 as a whole If any module errors are present the corresponding bit of the error summary will be set For example if the ERR query returns 0 00010000001 00000 there are errors on channels 13 and 6 Then read the module errors using the MODERR query For example Chan 13 Moderr and Chan 6 Moderr queries could be sent For more information on LDC 3916 mainframe errors refer to Chapter 3 of the LDC 3916 Instruction Manual Table 3 3 LDC 3916330 Series Error Message Codes Error Code E 103 E 104 E 105 E 106 E 114 E 123 E 126 E 201 E 202 E 203 E 204 E 205 E 206 E 207 E 208 E 209 E 210 E 211 E 212 E 214 E 222 E 223 E 226 Explanation Length of arbitrary block is different from expected length Parameter is an undefined numeric type Parameter has an invalid exponent A digit was expected in the parameter but was not found Specified arbitrary block length is invalid Command is not found Wrong number of parameters for command Parameter value out of range Error in conversion of parameter type Command is a secure command but secure commands are disabled Suffix is invalid Expected Boolean parameter is invalid Error in conversion to signed 16 bit integer Error in conversion to unsigned 16 bit integer Error in conversion to signed 32 bit integer Error in convers
6. State Disabled Disabled Enabled Enabled Enabled Enabled Disabled Enabled Note Bit 7 is Laser Open Circuit in the Laser Condition and Event registers It is not available to disable in the Output Off Enable register because it is always active in the hardware LDC 3916330Series 31 32 REMOTE OPERATIONS Status Reporting Turn Output Off C gt UO I LOGICAL OR PEPEPEEEEEEEEEEE LASERn Output Off Register bit wise LOGICAL AND LASERn Output Off Enable Register LASERn Output Off Bit Reference Current Limit Voltage Limit n a Power Limit n a n a n a n a 8 z Out of Tolerance n a n a n a n a n a n a n a LASERn ENABle OUTOFF lt nrf gt LASERn ENABle OUTOFF Figure 3 4 LDC 3916330 Series Laser Diode Controller LASER Output Off Register LDC 3916330 Series Lightwave 09 07 REMOTE OPERATIONS Error Messages Error Messages This section contains descriptions of the errors which are specific to the LDC 3916330 Series modules These are the error codes that are returned from the MODERR query Refer to the LDC 3916 Laser Diode Controller Instruction Manual Chapter 3 for a list of LDC 3916 mainframe error codes and descriptions the codes returned from the ERR query During remote operation the recommended method for error testing is as follows
7. User s Guide Laser Diode Current Source Modules TN LDC 3916330 Series 5 A Newport Corporation Brand ILX Lightwave Corporation 31950 Frontage Road Bozeman MT U S A 59715 U S amp Canada 1 800 459 9459 International Inquiries 406 556 2481 Fax 406 586 9405 ilx custhelp com www ilxlightwave com 70028104 June 2013 TABLE OF CONTENTS E m L a Bl El El m Bl L El m L Safety Information and the vii General Safety Considerations vii Safety Marking Symbols viii Comments Suggestions and Problems x Chapter 1 Introduction and Specifications Safety Symbols and 1 Product Overview 2 Installing the LDC 3916330 Series Laser Diode Controller Module 2 Installation into LDC 3916 Laser Diode Controller Mainframe 2 General Shipping 5 3 Calibration and Repair Services 3 General Shipping 5 5 3 Specifications 22 22222 2 8 ERE ed A E a 4 Chapter 2 Operations Connecting to the Laser Current Source 8 interlock Connections dnt bo
8. This measurement is derived from the monitor photodiode current MDI it is calculated by dividing MDI by CalPD If CalPD is 0 this query returns 1 0 This measurement is updated approximately once every 600 msec Examples Laser1 MDp response 100 0 means Laser1 s optical power is calculated to be 100 mW 60 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn MODE Cc DEVICE DEPENDENT FRONT PANEL The LASERn MODE query returns the selected module s laser control mode TOPPO Parameters None The response is character data which represents the LAS operating mode Notes IHBW mode is the same as ILBW mode low bandwidth except that the output low bandpass filter is disabled in IHBW mode Examples LASER1 MODE response ILBW means that constant current low bandwidth mode is in effect for the selected module s Laser1 output Laser1 Mode response MDP means that constant optical power is in effect for the selected module s Laser1 output Laser1 Mode response MDI means that constant monitor current mode is in effect for the selected module s Laser1 output 1 response IHBW means that constant current high bandwidth mode is in effect for the selected module s Laser1 output LASERn MODE C DEVICE DEPENDENT FRONT PANEL The LASERn MODE command path is used access the selected module s las
9. To do this select the CalPD parameter and adjust it to the correct value The CalPD units are uL A mW A method to calculate the responsivity value CalPD is suggested here Measure with a calibrated detector the output power of the laser Measure the corresponding monitor photodiode current e Calculate the responsivity CalPD by dividing the photodiode current by the optical power noting the units required are pA mW Setting the Photodiode Bias Voltage Now push the DOWN soft key F4 to display LAS p 3 of the laser setup menu The Bias parameter setting controls whether or not a bias voltage is applied to the monitor photodiode Select the Bias parameter and adjust it ON or OFF depending on whether you want a 5 volt reverse bias on your photodiode or not Many laser diode modules are tested and characterized by the manufacturer with a 5 volt reverse bias on the photodiode This bias can decrease the response time and increase the linearity and or saturation level of the photodiode 09 07 LDC 3916330Series 21 OPERATIONS Operating a Laser in Constant Power P Mode Constant Power Mode if CalPD is Unknown em Ch 1 LAS 2 a OFF Ipdset nos vA Pset E P1 im 1 0 Ex 520 8 8 8 8 8 TE p on If you do not know the correct photodiode responsivity CalPD value the LDC 3916330 Series Modules can still drive your laser at a constant light powe
10. nrf value The response is in uA and is valid even when the unit is not in MDI mode This measurement is updated approximately once every 600 msec Laser1 MDi response 57 3 means 57 3 of photodetector current was measured in the selected module s Laser1 monitor photodiode circuit LDC 3916330 Series 59 4 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn MDP DEVICE DEPENDENT FRONT PANEL The LASERn MDP command sets the value of the selected module s laser optical power set point in mW white nrf space value Parameters nrf value which represents the selected module s optical power setpoint in mW Notes In constant optical power MDP mode the output current is controlled so that the optical power remains constant at the MDP setpoint See the LASERn Mode command for more information If CALPD is 0 the actual set point will be approximately 0 On the front panel the monitor photodetector power is referred to as PPD Examples Laser1 Mdp 40 action the selected module s Laser1 power setpoint is set to 40 mW LASERn MDP C DEVICE DEPENDENT FRONT PANEL The LASERn MDP query returns the value of the selected module s laser photodetector power measurement in mW Parameters None The response is an nrf value Notes The response is in mW The response is valid even when the unit is not in constant power mode
11. procedure will perform the calibration for the laser forward voltage measurement circuit The cal procedure will then set the status to the value 2 to indicate that it has finished 86 LDC 3916330 Series uix Lightwave TROUBLESHOOTING Troubleshooting Guide Troubleshooting Guide This section is a guide to troubleshooting the 3916330 Series Controller Modules Some of the more common symptoms are listed here and the appropriate troubleshooting actions are given We recommend that the user start at the beginning of this guide Read the symptom descriptions and follow the steps for the corrective actions which apply If you encounter problems which are beyond the scope of this guide contact ILX Lightwave Customer Service SYMPTOM CORRECTIVE ACTIONS GENERAL LDC 3916 Series instrument will not Check AC power line voltage and power word power up connection Power on but outputs have been shut off This may occur if the instrument loses power AC line Instrument may be locked up or briefly or line voltage drops below specification If instrument resets itself instrument is locked up power it off and then on to restart LASER CURRENT SOURCE Power on but no current output Check interlock pins on LASER input connector on instrument rear panel These pins must be shorted either directly or through a switch The front panel Laser Enable switch should also be on If Open Circuit is indicated E5
12. 20 Setting the Responsivity Value CalPD 21 Setting the Photodiode Bias Voltage 21 Constant Power Mode if CalPD is Unknown 22 Turning the Laser Current Source 22 Conditions Which Will Automatically Shut Off the Laser Output 23 Laser Error Indicators 24 Chapter 3 Remote Operations Remote Configuration 25 LDC 3916330 Series Laser Diode Controller Command Set 25 LDC 3916330 Series Laser Diode Controller Often Used Commands 27 Command Timing and Completion 27 Status Reporting 28 Status Registers fines ex kp Gua tetas pe XO RR 28 Outp t Off REGISIENS i c bU E DO ead d de 31 Error Messages ses Eh xe E eux Rhe xm oreet 33 ii LDC 3916330 Series Lightwave Chapter 4 Command Reference LDC 3916330 Series Device Dependent Command Reference 38 Chapter 5 Troubleshooting Calibration Overview 75 Recommended 75 Local Calibration of the Laser Current 78 Current Source Calibration 78 IPD Current
13. COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn SYNCLDV COMMON DEVICE DEPENDENT The LASERn SYNCLDV query returns the value of the selected channel s measured laser voltage in volts DX o o SYNCLDV gt Parameters None The response is an lt nrf value gt representing voltage in volts Notes This is a synchronized measurement the measurement system is connected to the voltage measurement signal when this query is received A voltage measurement is made and the result is returned as the response After the measurement is made the measurement system returns to its normal function switching between the various signals and measuring them The response time to this query is from 200 msec to 250 msec but the measurement is made as soon as the query is received In contrast the laser Idv query returns immediately but the measurement can be up to 600 msec old Examples LASER1 syncldv response 3 03 means the measured LASER output voltage is 3 03 volts LASERn SYNCMDI DEVICE DEPENDENT LASERn SYNCMDI query returns the value of the selected channel s measured monitor photodiode current in pA Parameters None The response is an nrf value representing current nA Notes This is a synchronized measurement the measurement system is connected to the monitor current measure signal when this query is received The photodiode current measureme
14. Cal Stat response 0 means the module is not yet ready for the LASER1 calibration measurement value to be entered 44 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn COND COMMON DEVICE DEPENDENT The LASERn COND query returns the contents of the selected module s laser condition status register TOPO Parameters None The response is the sum of the following 1 Current Limit 256 Output is Shorted 2 Voltage Limit 512 Output in Tolerance 4 N A 1024 Output On 8 Power Limit 2048 N A 16 Interlock Disabled 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit 32768 N A Notes The conditions which are reported to the 3916 status byte are set using the LASERn ENABle COND command for each channel See the Status Reporting section of the 3916 manual for more complete information The open circuit condition can only be present while a laser output is on when the hardware detects this condition it will turn that laser output off Therefore the open circuit condition is fleeting and may be missed with the LASERn COND query The user should test for the open circuit event using the LASERn EVEnt query The condition status is constantly changing while the event status is only cleared when the event status is read or the CLS or RST command is issued NOTE The voltage limit condition occurs as a warning when th
15. TROUBLESHOOTING _ Local Calibration of the Laser Current Source Laser Forward Voltage Measurement Calibration The following procedure is for calibrating the LASER forward voltage LDV measurement circuits The internal calibration procedure sets the current to two values You must enter the resulting forward voltage that you measure at both of these points The internal procedure will then use this information to calibrate the LDV measurement circuit 1 With the output off connect the specified load resistor see Table 5 2 to the LASER output terminals Laser Anode Pin 9 and Laser Cathode pin 5 2 Connect a voltmeter with at least a 15V range and an accuracy of at least 0 01V across the load resistor 3 Enter the LDV calibration mode by pushing the DISPLAY MAIN front panel button then the SYS CONFIG soft key then the CAL soft key For the 3916332 or 3916334 modules press Cal LAS1 or Cal LAS2 to choose which source to calibrate on the dual current source modules or Cal LAS for the 3916338 module single current source module Then press the LDV Cal soft key the module s LDV calibration screen will appear 4 Press the START soft key The internal calibration procedure will turn on the output and drive the LD current to approximately 25 of full range Allow the current to settle for at least 10 seconds 5 Then measure the voltage across the load resistor enter that value in Volts into the highlighted VReal adjust field on
16. about potentially dangerous situations which can result in death injury or damage to the instrument and other components Caution Visible and or refer to ground NU invisible laser manual Terminal radiation Caution risk Protective Frame or of electric Conductor E hot chassis shock Terminal Terminal dh On In position of a bistable push control The O Off Out position of a bistable push control or 1 slash 1 only denotes that mains are on or The circle only denotes that mains are off LDC 3916330 Series Lightwave WARRANTY ILX LIGHTWAVE CORPORATION warrants this instrument to be free from defects in material and workmanship for a period of one year from date of shipment During the warranty period ILX will repair or replace the unit at our option without charge Limitations This warranty does not apply to fuses lamps defects caused by abuse modifications or to use of the product for which it was not intended This warranty is in lieu of all other warranties expressed or implied including any implied warranty of merchantability or fitness for any particular purpose ILX Lightwave Corporation shall not be liable for any incidental special or consequential damages If a problem occurs please contact ILX Lightwave Corporation with the instrument s serial number and thoroughly describe the nature of the problem Returning
17. by selecting the P mode 18 7 LDC 3916330 Series Lightwave OPERATIONS Operating a Laser in Constant Power P Mode Setting the Current Limit DISPLAY j EL B4 0 8 88 Select the laser current limit Ilim parameter by pushing the DISPLAY UP DOWN ARROW keys until the Ilim value is highlighted with the cursor Adjust the current limit value with the numeric keypad the ADJUST knob or the ADJUST UP DOWN ARROW keys If you use the numeric keypad you mush push the ENTER key to store the value in memory within three seconds after entering the value or it will revert to the previous value The current limit protects your laser by never allowing the laser drive current to exceed the Ilim value independent of the current set point and the controller mode Constant Current or Constant Power A CAUTION Failure to set and ensure a proper current limit value could result in laser damage Setting the Voltage Limit Next select the laser voltage limit Vlim parameter using the DISPLAY UP DOWN ARROW keys Adjust this value to your desired laser voltage limit The voltage limit also protects your laser by shutting off the source driver if the laser 09_07 LDC 3916330 Series 19 y OPERATIONS Operating a Laser in Constant Power P Mode voltage exceeds the Vlim value The Vlim value should be set slightly above the operating voltage of the laser diode to provide maximum protect
18. file a claim with the carrier The factory will supply you with a quotation for estimated costs of repair You must negotiate and settle with the carrier for the amount of damage LDC 3916330 Series ix 7 Comments Suggestions and Problems To ensure that you get the most out of your ILX Lightwave product we ask that you direct any product operation or service related questions or comments to ILX Lightwave Customer Support You may contact us in whatever way is most convenient PHONG arae Reb eis 800 459 9459 or 406 556 2481 I CPU 406 586 9405 On the web http ilx custhelp com Or mail to ILX Lightwave Corporation P O Box 6310 Bozeman Montana U S A 59771 www ilxlightwave com When you contact us please have the following information Model Number Serial Number End user Name Company Phone Fax Description or sketch of what is connected to the ILX Lightwave instrument Description of the problem If ILX Lightwave determines that a return to the factory is necessary you are issued a Return Authorization RA number Please mark this number on the outside of the shipping box You or your shipping service are responsible for any shipping damage when returning the instrument to ILX Lightwave ILX recommends you insure the shipment If the original shipping container is not available place your instrument in a container wit
19. limit setting E404 E504 E504 Current Limit The current limit was reached This condition will cause an error indicator code and shut down the current source only when enabled through the GPIB interface otherwise a current limit will only limit the drive current at the limit value and indicate ILIM on the display E405 E505 E505 Voltage Limit The voltage on the laser current source is Warning approaching the limit value This condition will cause an error indicator code and shut down the current source only when enabled through the GPIB interface E407 E507 E507 Output Power Software calculated optical output power limit Limit was detected E408 E508 E508 TEC is off A TEC source such as a 3916558 which has been programmed to control this channel s laser module has turned off This condition will shut down the laser source only when enabled through the GPIB interface E409 E509 E509 TEC A TEC source such as a 3916558 which has Temperature been programmed to control this channel s laser Limit module has turned off due to a temperature limit condition This condition will shut down the laser source only when enabled through the GPIB interface E410 E520 E520 Tolerance Out of tolerance status forces LAS output off Event E411 E511 E511 Hardware Firmware has detected a hardware error error E429 E529 E529 Output off The laser source is off without hardware or when firmware indication controller detects on E435 E535 E535 M
20. low bandwidth Ilow Constant Optical Power P Constant Current high bandwidth Ihbw and Photodiode Current Ipd control modes Set the LDC 3916330 Series Controller Modules in Constant Current low bandwidth mode by selecting the Ilow mode Setting the Current Limit cont one Now select the current limit Ilim parameter using the DISPLAY UP DOWN ARROW keys Adjust the value to 175mA The current limit protects your laser by never allowing the laser drive current to exceed the llim value independent of the current set point and the controller mode Constant Current or Constant Power A CAUTION Failure to set and ensure a proper llim value could result in laser damage 14 7 LDC 3916330 Series Lightwave OPERATIONS Operating a Laser in Constant Current I Mode Setting the Constant Current Value Next select the Iset parameter on the setup menu using the DISPLAY UP DOWN ARROW keys This parameter sets the laser current source drive value when in or Ihbw modes Enter 150 mA using the numeric keypad the ADJUST knob or the ADJUST UP DOWN ARROW keys Push the ENTER key to store the value in memory within three seconds after entering the value using the numeric keypad or it will revert to the old value Setting the Voltage Limit mumm raam DISPLAY D i _ Select the voltage limit Vlim parameter and adjust it to 6 volts in the same manner as describe
21. lt 20 ppm lt 50 ppm Long Term Stability 24 hr lt 50 ppm lt 50 ppm lt 70 ppm Noise and Ripple 5 High Bandwidth Mode lt 10 uA rms lt 12 uA rms lt 36 uA rms Low Bandwidth Mode 5 pA rms lt 8 uA rms 24 uA rms Transients Operational 3mA 3mA 5mA 1kV EFT Surge 7 DRIVE CURRENT LIMIT SETTINGS 4 mA 8 mA 5mA 10 mA 5mA 10 mA Range 0 to 500 mA 0 to 1000 mA 0 to 3000 mA Resolution 0 2 mA 0 4 mA 1 025 mA Accuracy t mA 14mA 9mA Voltage Limit 0 to 6 0 V 0 to 6 0 V 0107 5 V Voltage Limit Resolution 02V 02V PHOTODIODE FEEDBACK Type Differential 100 Input Differential 100 Input Differential 100 Input Selectable Zero Bias or 5V Reverse Bias Selectable Zero Bias or 5V Reverse Bias Selectable Zero Bias or SV Reverse Bias PD Current Range 0 to 5 000 pA 0 to 5 000 uA 0 to 5 000 pA Output Stability 0 0196 X 0 0196 0 01 Accuracy set point of FS x 0 196 x 0 196 x 0 196 EXTERNAL ANALOG MODULATION Input 0 to 10V 50 Q 0 to 10 50 Q 0 to 8V 50 Q Transfer Function 50mA V 100 mA V 375 mA V 10 High Bandwidth Mode Small Signal Bandwidth DC to 1 2 MHz DC to 1 0 MHz DC to 0 6 MHz High Bandwidth Mode Large Signal Bandwidth DC to 1 0 MHz DC to 1 0 MHz DC to 0 6 MHz Low Bandwidth Mode DC to 30KHz DC to 30KHz DC to 30 kHz DRIVE CURRENT MEASUREMENT DISPLAY Output Current Range 0 to 500 00 mA 0 to 1000 0 mA 0 to 3000 0 mA Output Current Re
22. of the status menu displays laser diode current 1 LDI on line 1 and laser diode current 2 LDI on line 2 Examples STATMENU LINE1 response PPD means that optical power from laser 1 is selected to be displayed on line 1 STATMENU LINE2 response PPD means that optical power from laser 2 is selected to be displayed on line 2 STATMENU LINEn IPD DEVICE DEPENDENT The STATMENU LINE n IPD command sets the measurement that is to be displayed on line n of the status menu to photodiode current IPD PO OH SORE Parameters None Notes The default condition of the status menu displays laser diode current 1 LDI on line 1 and laser diode current 2 LDI on line 2 Examples STATMENU LINE1 IPD response photodiode current of laser 1 is displayed on line 1 of the status menu STATMENU LINE2 IPD response photodiode current of laser 2 is displayed on line 2 of the status menu 09 07 LDC 3916330Series 71 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference STATMENU LINEn LDI DEVICE DEPENDENT The STATMENU LINEn LDI command sets the measurement that is to be displayed line n of the status menu to LASER diode current LDI Ov SOE Parameters None Notes The default condition of the status menu displays laser diode current 1 LDI on line 1 and laser diode current LDI on line 2 Examples STATMENU LINE1 LDI response laser
23. photodiode is internally connected to either the laser anode or cathode The photodiode and laser connections to the LDC 3916330 Series Module are electrically isolated from ground and each other So if a 4 pin connection is made no common connections no additional jumpers are required Figures 2 1 2 4 show the recommended connections and shielding for 3 pin lasers where the common connection is internal to the device A 4 pin laser should be connected with the same shielding as shown in Figure 2 1 but the common connection between the photodiode and the laser is optional Grounding Considerations The LASER outputs of the LDC 3916330 Series Laser Diode Controller Module are isolated from chassis ground allowing either output terminal to be grounded at the user s option Figure 2 1 shows the proper earth ground shielding for laser diode photodiode connections 09 07 LDC 3916330Series 11 OPERATIONS _ Operating the Laser Current Source from the Front Panel Operating the Laser Current Source from the Front Panel The various laser current source control parameters can be set the same for all channels via the All Chnl menu which is accessed through the MAIN menu Alternatively the laser source control parameters for each individual channel can be set independently via channel setup menus which are accessed through the CHAN menu You can move between multiple pages of any setup menu by pushing the up and down arrow soft k
24. sensing the various limits can be controlled via the GPIB interface Most high limit responses can be set to either turn off the source or just give a limit warning through the GPIB interface See the LAS ENAB OUTOFF command in Chapter 4 of this manual for more information 09 07 LDC 3916330 Series 23 24 OPERATIONS Laser Error Indicators Laser Error Indicators The LDC 3916330 Series Laser Diode Current Source Controllers indicate general LASER operational error conditions When an error occurs the Error Indicator Code will appear on the status page the Chan page or the LAS setup pages for the respective current source Laser error indicator codes are summarized in Table 2 2 The error indicator code will clear if you exit any page that it appears on after the error has been corrected The output drive will shut off when and laser error code occurs Error codes that start with 4 are for the 51 current source Error codes that start with E5 are for the LAS2 current source Table 2 2 LASER Error Indicators Error Code Description Probable Cause LDC 3916332 334 LDC 3916338 LAS1 LAS2 LAS E401 E501 E501 Interlock Interlock pins not connected properly or LASER ENABLE key lock turned off on front panel E403 E503 E503 Voltage Limit The laser current source pins are open or some or Open condition caused the laser voltage to exceed the Circuit voltage
25. voltage regardless of control mode This measurement is updated approximately once every 600 msec Examples LASER1 Idv response 3 03 means the measured Laser1 output voltage is 3 03 volts LASER1 LDV response 1 0 means the measured Laser1 output voltage is 1 00 volts 09_07 LDC 3916330 Series 55 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn LIMIT C DEVICE DEPENDENT FRONT PANEL The LASERn LIMit command path is used to access the selected module s limit commands The following commands may be reached directly from the LASERn LIMit command path LASERn LIMit I LASERn LIMit MDP LASERn LIMit V LASERn LIMit I LASERn LIMit MDP LASERn LIMit V LASERn LIMit I DEVICE DEPENDENT FRONT PANEL The LASERn LIMit command sets the selected module s laser current limit value Parameters nrf value which represents the selected module s laser limit current in mA Notes The current limit is in effect in all modes of operation Examples LASER1 LIM I 80 action the selected module s Laser1 current limit is set to 80 mA Laser1 Limit 160 action the selected module s Laser1 current limit is set to 160 mA LASERn LIMit I DEVICE DEPENDENT FRONT PANEL The LASERn LIMit I query returns the value of the selected module s laser current limit Parameters None The response in an nrf value Notes The current limit is valid fo
26. volts The llbw mode uses a low pass filter on the laser drive current output to significantly reduce noise In this mode a low bandwidth modulation input may be used via the back panel MODULATION connector Follow the instructions below in the sequence presented to program the current source for a single channel Entering the Laser Channel Setup Menu a Lok T p Push the CHAN key display the single channel menu From this menu you see the measured parameters enter the LAS1 or LAS2 channel setup menus 8916332 334 modules or the LAS setup menu 3916338 or turn the current sources on and off Use the ADJUST UP DOWN ARROW keys or the ADJUST knob to select the desired channel number highlighted at the top of the display For the 3916332 334 modules push the DISPLAY LAS1 soft key F2 to enter page 1 of the laser channel setup menu Push the LAS2 soft key F4 to program the second current source in this module For the 3916338 module push the display down arrow soft key F4 to enter page 1 of the laser channel set up menu 09 07 LDC 3916330 Series 13 OPERATIONS Operating a Laser in Constant Current I Mode Setting the Mode of Control DISPLAY ont ono Select the Mode parameter by pushing the DISPLAY UP DOWN ARROW keys until the Mode parameter is highlighted Repeatedly pushing the ADJUST UP DOWN ARROW keys or turning the ADJUST knob will cycle through the Constant Current
27. 03 check the load connections and cable and then try again Be sure the cable connector is securely fastened to the back of the module s Also check that the Voltage Limit setting is above the laser s operating voltage Unable to adjust output Check the OUTPUT ON soft key It should read ON Check the instrument mode the channel number and the laser current limit Output current at limit can t be lowered If IPD or PPD mode is used check the monitor diode feedback connections Try reversing the polarity of the monitor photodiode Also check if the photodiode bias is off If in lj gyy or mode check the current set point and LIMIT setting Setting the output below the limit may require several turns of the adjust knob if the set point is much greater than the desired limit setting Output goes off intermittently Check the interlock circuit An intermittent interlock will turn the output off Check that the AC power cord connection is secure Power line drop outs may reset the unit and when power is restored the output will be off 09 07 LDC 3916330 Series 87 TROUBLESHOOTING Troubleshooting Guide Unable to adjust output Make sure that the ISET adjust parameter is highlighted Check the ILIMIT parameter it should be set above 0 and above the laser operating current Check the VLIMIT parameter it should be set above the voltage condition of your laser load Power Mode operatio
28. 09 07 LDC 3916330 Series 49 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn ENABl1le EVEnt COMMON DEVICE DEPENDENT The LASERn ENABle EVEnt query returns the contents of the selected module s laser event status enable register POP Parameters None The response is the sum of the following 1 Current Limit Changed State 256 Output Shorted Changed State 2 Voltage Limit Changed State 512 Output Changed Tolerance State 4 N A 1024 Output On Changed State 8 Power Limit Changed State 2048 N A 16 Interlock Changed State 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit Changed State 32768 N A Notes The register is set using the LASERn ENABle EVEnt command The selected module s laser event status can be monitored by the LASERn EVEnt query Examples LASER1 ENAB EVE 256 means that the selected module s Laser1 output shorted changed state event is the only event that will be reported to the 3916 status byte 50 LDC 3916330 Series uix Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn ENABle OUTOFF DEVICE DEPENDENT The LASERn ENABle OUTOFF command sets the selected module s laser output off enable register The bits in this register specify the conditions that will cause the Laser1 current source to automatically turn off HO Parameters nrf val
29. 1 CAL Default action the selected module sets all of its Laser1 calibration constants to default values LASERn CAL LDI COMMON DEVICE DEPENDENT FRONT PANEL The LASERn CAL LDI command is used to initiate the calibration procedure for the selected module s laser current setpoint measurement and current limit TOPPO e Parameters None Notes Both low and high bandwidth modes along with current limit are calibrated during this procedure See the Service Reference portion of this manual for complete calibration instructions Examples Laser1 CAL Ldl action the selected module enters calibration mode for Laser1 current 42 7 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn CAL LDV DEVICE DEPENDENT FRONT PANEL The LASERn CAL LDV command is used to initiate the calibration procedure for the selected module s laser voltage measurement POP pOr pore Parameters None Notes See the Service Reference portion of this manual for complete calibration instructions Examples Laser1 CAL Ldv action the selected module enters calibration mode for Laser1 voltage measurement LASERn CAL MDI OMMC DEVICE DEPENDENT FRONT PANEL The LASERn CAL MDI command is used to enter the photodiode current calibration mode porte Parameters None Notes See the Service Reference portion of this manual for complete calibration instructions
30. 16330Series v vi 7 LDC 3916330 Series Lightwave SAFETY AND WARRANTY INFORMATION E El El El El a L m El L El El El Ei The Safety and Warranty Information section provides details about cautionary symbols used in the manual safety markings used on the instrument and information about the Warranty including Customer Service contact information Safety Information and the Manual Throughout this manual you will see the words Caution and Warning indicating potentially dangerous or hazardous situations which if not avoided could result in death serious or minor injury or damage to the product Specifically A CAUTION Caution indicates a potentially hazardous situation which can result in minor or moderate injury or damage to the product or equipment Warning indicates a potentially dangerous situation which can result in serious injury or death WARNING Visible and or invisible laser radiation Avoid direct exposure to the beam General Safety Considerations If any of the following conditions exist or are even suspected do not use the instrument until safe operation can be verified by trained service personnel Visible damage e Severe transport stress Prolonged storage under adverse conditions Failure to perform intended measurements or functions If necessary return the instrument to ILX Lightwave or authorized local ILX Lightwave distributor for Service or repai
31. 330 Series modules Note The LDC 3916332 and 3916334 modules each contain two fully independent laser diode current sources The top connector on the back of the module is for the source called LAS1 and the bottom connector is for the current source called LAS2 Each of these two sources must be programmed separately before turning the respective source on Table 2 1 LDC 3916330 Series Controllers Default Settings Lightwave LASER CURRENT CONTROLLER LASER output off ISET 50 mA ILIM 150 mA VLIM 5 0 V Constant I low bandwidth mode Modulation off PPD Set Point 3 0 W CAL PD 0 0 uLA mW PLIM 500 mW PD Bias off LASER STEP value 0 1mA LASER Tolerance values 10 mA 1 0 seconds IPD Set Point 100 pA LDC 3916330 Series El OPERATIONS _ Connecting to the Laser Current Source Connecting to the Laser Current Source When connecting your laser diode or any other sensitive devices to the LDC 3916330 Series Dual Current Source Modules we recommend that the instrument be powered up and the LASER outputs be off In this condition a low impedance shunt is active across the output terminals When disconnecting devices it is only necessary to turn the LASER outputs off It is also recommended that the connections to the LDC 3916330 Series module output be made using twisted wire pairs with an earth grounded shield see Figures 2 1 2 4 We recommend using our CC 303 Shielded Laser Cable which is
32. 5 of full range Allow the current to settle for at least 10 seconds Calculate or measure the actual current through the load resistor enter that value in mA into the highlighted IReal adjust field on the screen and press ADJUST ENTER Do not enter more than eight characters including the decimal point The internal cal procedure will then set the LD current to approximately 75 of full range Allow the current to settle for at least 10 seconds Measure the actual current and enter that value into the IREAL adjust field Lightwave TROUBLESHOOTING Local Calibration of the Laser Current Source After you have entered the second value the internal cal procedure calibrates the LD current measurement circuit the LD current source for both low and high bandwidths and the LD current limit circuit IPD Current Calibration The following procedure is for calibrating the LASER Ipp photodiode monitor measurement circuits The internal calibration procedure sets the current to two values You must enter the resulting lpp photodiode monitor current that you measure at both of these points The internal procedure will then use this information to calibrate the Ipp measurement circuit 1 With the output off connect the IPD calibration circuit Figure 5 1 to the appropriate laser connector 2 Connect an ammeter with at least 5000 pA range and at least 0 1 pA accuracy as shown in Figure 5 1 This ammeter is in serie
33. 6330 Series 29 REMOTE OPERATIONS ud Status Reporting LASER Event Status Register LASER 1 EVEnt 6 5 4 3 2 1 0 421025001017 eee FEEFEE LASER1 Event Status Enable Register LASERT ENABIe EVEnt lt nrf gt LASER1 ENABle EVEnt I rods LOGICAL OR Register LASER2 Event Status Register LASER2 EVEnt 71615 413 2 10 1 E i i i i i E 1 H H OR LOGICAL AND LASER2 Event Status Enable Register LASER2 ENABlIe EVEnt lt nrf gt LASER2 ENABle EVEnt LASER 1 Event Bit Reference LASER2 Event Bit Reference 0 Current Limit 8 Output Shorted 0 Current Limit 8 Output Shorted 1 Voltage Limit 9 Tolerance Change 1 Voltage Limit 9 Tolerance Change 2 n a 10 Output On 2 n a 10 Output On 3 Power Limit 11 n a 3 Power Limit 11 4 Interlock Error 12 4 Interlock Error 12 n a 5 n a 13 n a 5 n a 13 6 14 6 n a 14 n a 7 Open Circuit 15 n a 7 Open Circuit 15 n a Figure 3 3 LDC 3916330 Series Event Registers 30 LDC 3916330 Series uix Lightwave REMOTE OPERATIONS Status Reporting Output Off Registers The Output Off Enable Registers allow you to determine which conditions and events in the TEC and LASER controllers can cause their outputs to be turned off These regi
34. 916330 Series uix Lightwave CHAPTER 5 TROUBLESHOOTING El a E El w a E El mH E Li EH Li a This chapter describes calibration of your LDC 3916330 Series Dual Laser Diode Controller Module Descriptions of the required test instruments calibration conditions and the detailed procedures for calibration of the instrument s Temperature Controller and the 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 on each of the two current sources to completely calibrate the 3916330 Series Module The calibration for each source consists of calibrating the current source the photodiode monitor feedback ammeter and the forward voltage measurement The current limits are calibrated internally by the instrument using measurements supplied by the user as part of the calibration process Your 3916330 Series Module can be calibrated while installed in the 3908 3916 or 3926 mainframe with the case closed It should be calibrated every 12 months or whenever performance verification indicates that calibration is necessary such as differences between set point and measurement display values which exceed the accuracy specification Calibrate t
35. AL CLS XESE ESE ESR gt XDN OPC OPC PSC PSC PUD PUD ARCL ARST AS AV XSRE XSTB TST WAI 26 ALLCOND MODERR ALLEVE MODIDN BEEP MODPUD BEEP MODPUD CHAN STATMENU LINEn CHAN STATMENU LINEnLDI CHECKSUM STATMENU LINEnPPD DELAY STATMENU LINE nIPD ERR STATMENU LINEnVF MENU 10 2 MES MES RAD RAD SECURE TERM TERM TIME TIMER root LASERT or LASER2 BIAS ENAB MODE 5 BIAS CALPD COND HBW LDI CALPD COND 1 MDI DEFAULT COND EVE MDP LDI DEC EVE MDP MDI QUTOFF MEAS INC OUTOFF V MDI 101 STAT VALUE LDV LDV MDI MDI MODE MOD MOD OUT OUT STEP STEP SYNCLDI SYNCLDV SYNCMDI SYNCMDP TOL TOL Figure 3 1 LDC 3916 and LDC 3916330 Series Command Path Structure LDC 3916330 Series Lightwave REMOTE OPERATIONS kg LDC 3916330 Series Laser Diode Controller Often Used Commands CHAPTER S LDC 3916330 Series Laser Diode Controller Often Used Commands Table 3 1 LDC 3916330 Series Often Used Commands NAME PARAMETERS FUNCTION CHAN Sets the channel or ALL channels for further commands Returns Mainframe errors generated since the last query followed by a binary representation of existing module
36. ASERn DEVICE DEPENDENT FRONT PANEL The LASERn command path is used to get to the LDC 3916330 Series Laser Diode Current Source s laser current source commands The following command paths may be reached from the LASER command path LASERn CAL LASERn MODE LASERn ENABle LASERn SET LASERn LIMit The following commands may be reach directly from the LASER1 command path LASERn BIAS LASERn LDV LASERn STEP LASERn BIAS LASERn MDI LASERn STEP LASERn CALPD LASERn MDI LASERn SYNCLDI LASERn CALPD LASERn MDP LASERn SYNCLDV LASERn COND LASERn MDP LASERn SYNCMDI LASERn DEC LASERn MODE LASERn SYNCMDP LASERn EVEnt LASERn MODulation LASERn TOL LASERn INC LASERn MODulation LASERn TOL LASERn LDI LASERn OUTput LASERn LDI LASERn OUTput 38 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn BIAS COMMON DEVICE DEPENDENT FRONT PANEL The LASERn BIAS command turns the selected channel s laser photodiode bias on or off rO EHE Parameters nrf value 1 on 0 off Notes When the BIAS is on a bias of 5 volts is placed across the photodiode terminals Examples LASER1 BIAS ON action sets Laser1 photodiode bias output on LASER BIAS ON action sets the laser photodiode bias on LDC 3916338 only LASERn BIAS COMMON DEVICE DEPENDENT FRONT PANEL The LASERn BIAS query returns the status of the selected module s photodio
37. L MDI LASERn CAL MEAS LASERn CAL STATUS LASERn CAL VALUE LASERn CAL ABORT COMMON DEVICE DEPENDENT FRONT PANEL The LASERn CAL ABORT command is used to exit the selected module s laser calibration procedure without changing the calibration values 0090 0 09 Parameters Notes If this command is issued while the LDC 3916330 Series Dual Laser Diode Current Source is in a laser calibration the calibration will be terminated and the module will operate with the same calibration values as before the calibration mode was started This command is intended for use after a false or invalid calibration is entered or to exit calibration mode before any values have been entered Examples Laser1 CAL ABORT action module exits calibration mode 09 07 LDC 3916330 Series 41 4 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn CAL DEFAULT C DEVICE DEPENDENT FRONT PANEL The LASERn CAL DEFAULT command sets all of the selected module s laser calibration constants to default values vor eoo Parameters None Notes This command should only be used in the case in which the calibration has become corrupted and circumstances make calibration impossible Measurements and setpoints on the laser current source are not guaranteed to meet accuracy specifications after this command is issued Accuracy will remain unspecified until calibration is performed on the module Examples Laser
38. LAS2 output off E 511 Laser 2 Hardware Error forces output off e g low power line voltage E 529 Laser 2 Output is off but Laser 2 status thought it was on E 535 Laser 2 Mode changed while output on E 601 Internal error recalled bin has incorrect checksum Settings do not match bin E 602 Internal error task synchronization error E 620 Internal error resource unavailable E 621 Internal error message undeliverable to task E 622 Internal error could not send message to mainframe E 710 Internal error AC power low error detected E 711 Internal error AC power low error detected E 712 Internal error Over temperature error detected on internal sensor E 713 Internal error Power brown out error detected E 714 Internal error Writing to display E 802 Calibration error measurement entered before calibration was ready 34 LDC 3916330 Series Lightwave CHAPTER COMMAND REFERENCE El a E El w Li E B E a a El El L This chapter is a guide to all of the device dependent commands for the LDC 3916330 Series Dual LASER Diode Controller module The first part contains an overview of the remote commands used by the LDC 3916330 Series The second part contains all of the LDC 3916330 Series commands in alphabetical order Table 4 1 lists the commands for the LDC 3916330 Series modules It uses the nomenclature LASER in places to indicate that a command can be sent either to the LASER1 current sou
39. LDC 3916330 Series Device Dependent Command Reference LASERn SET DEVICE DEPENDENT FRONT PANEL The LASERn SET command path is used to access the selected module s laser set point queries The following commands may be reached directly from the LASERn SET command path LASERn SET LDI LASERn SET MDI LASERn SET MDP LASERn SET LDI C DEVICE DEPENDENT FRONT PANEL The LASERn SET LDI query returns the selected module s laser constant current setpoint This value is used for both bandwidth modes IHBW and ILBW vOpee pore PO Parameters Notes Examples None The response is an lt nrf value gt which represents the selected module s constant set point value in mA The LDI set point is only in effect when the operating mode is IHBW or ILBW LASER1 SET LDI response 50 0 means the selected module s LASERn output current set point value is 50 0 mA LASERn SET MDI DEVICE DEPENDENT FRONT PANEL The LASERn SET MDI query returns the selected module s photodiode current setpoint value pore por Parameters Notes Examples LDC 3916330 Series None The response is an nrf value which represents the selected module s constant MDI set point in uA The monitor photodiode current is dependent on the laser optical output power Therefore the set point may be used to control optical output of the laser Laser1 set mdi response 30 0 means the selected module
40. Which Will Automatically Shut Off the Laser Output Conditions Which Will Automatically Shut Off the Laser Output When the LASER output is off an internal short is placed across the LASER output The default condition for the current source output is OFF when the instrument is first powered up With the laser output enabled the channel or status displays should be indicating measured laser current If the output won t function or an error code appears check the conditions shown below or table 2 3 LASER Error Indicators The following conditions will automatically force the laser current source to turn off 1 LASER High Power Limit Plim E507 LASER High Voltage Limit Vlim E503 or E505 LASER ENABLE Interlock E501 LASER ENABLE Key Lock turned off on the front panel E501 LASER Open Circuit E503 a PN High Temperature Limit Condition E509 In addition the LASER Current Limit setting llim will clip the laser drive current at the llim set point when the signal is being modulated When the LASER current limit Ilim is reached an ILIM warning will appear on the CHAN menu display The current limit setting is independent of the voltage drop of the device connected to the LASER output Furthermore since the current limit circuitry is fully independent of the main current control the current limit can be adjusted safely even while the LASER output is active The LDC 3916330 Series Modules response to
41. a unique twisted pair cable with braided outer shield designed to provide the best possible rejection of most transient noise signals 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 grounds in the circuit Multiple earth grounds may provide circuit paths that induce spurious currents in the photodiode feedback circuit and output leads Note Experience indicates that should an inadvertent open circuit occur during laser operation while the LASER is ON your laser may be damaged by a momentary circuit break and remake before the final circuit break Your new LDC 3916330 Series Module has circuitry designed to detect open circuits and will shut the output off under most conditions However we recommend that cable connections to the laser be secure enough that they won t open circuit should they be jostled or bumped Note Use appropriately shielded cabling to reduce coupling of potentially laser damaging transients Do not bundle the current source cables with other cables in your system or laboratory See Application Note 3 Laser Diode Protection Strategies for more detailed discussions on connecting to your laser Figures 2 1 2 4 show the possible configurations of conn
42. an Instrument If an instrument is to be shipped to ILX Lightwave for repair or service be sure to 1 Obtain a Return Authorization number RA from ILX Customer Service 2 Attach a tag to the instrument identifying the owner and indicating the required service or repair Include the instrument serial number from the rear panel of the instrument 3 Attach the anti static protective caps that were shipped with the instrument and place the instrument in a protective anti static bag 4 Place the instrument in the original packing container with at least inches 7 5 cm of compressible packaging material Shipping damage is not covered by this warranty 5 Secure the packing box with fiber reinforced strapping tape or metal bands 6 Send the instrument transportation pre paid to ILX Lightwave Clearly write the return authorization number on the outside of the box and on the shipping paperwork ILX Lightwave recommends you insure the shipment If the original shipping container is not available place your instrument in a container with at least 3 inches 7 5 cm of compressible packaging material on all sides Repairs are made and the instrument returned transportation pre paid Repairs are warranted for the remainder of the original warranty or for 90 days whichever is greater Claims for Shipping Damage When you receive the instrument inspect it immediately for any damage or shortages on the packing list If the instrument is damaged
43. annel the laser current may be modulated by connecting a modulation signal onto the back panel MODULATION connector BNC The modulation bandwidth depends on the operating mode and the module used Refer to Chapter 1 Specifications for more information on bandwidth specification Examples LASER1 LDI 20 LASER1 MOD ON action sets the selected module s Laser1 output current to 20 mA and then turns the selected module s Laser1 modulation switch on Laser1 Mod 0 action disables modulation of the selected module s Laser1 current source LASERn MODulation DEVICE DEPENDENT FRONT PANEL The LASERn MODulation query returns the status of the selected module s laser modulation switch 9 Parameters None The response is an lt nrf value 1 on enabled 0 off disabled Notes More than one channel at a time may be modulated via the modulation signal if desired Examples Laser1 MODULATION response 0 means that the selected module s Laser1 modulation switch is disabled LASER1 MOD response 1 means that the selected module s Laser1 modulation switch is enabled A signal applied to the back panel modulation connector will modulate the selected module s Laser1 current 64 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn OUTput COMMON DEVICE DEPENDENT FRONT PANEL The LASERn OUTput command turns
44. ata from the module MODPUD 1 Used at factory to set calibration information MODPUD NONE Returns factory set calibration information STATMENU LINEn NONE Returns the name of the measurement that is displayed on line n of the status menu n can be either 1 or 2 STATMENU LINEn LDI NONE Sets line n of the status menu to display LASER current STATMENU LINEn VF NONE Sets line n of the status menu to display LASER forward voltage STATMENU LINEn IPD NONE Sets line n of the status menu to display photodiode current STATMENU LINEn PPD NONE Sets line n of the status menu to display optical power 09 07 LDC 3916330 Series 37 4 COMMAND REFERENCE _ LDC 3916330 Series Device Dependent Command Reference LDC 3916330 Series Device Dependent Command Reference This section contains all of the device dependent commands for the LDC 3916330 Series Laser Current Source Modules listed in alphabetical order Sub sections for each path are presented listing the commands which are legal for that path See Chapter 3 Figure 3 1 for command path tree structure The following pages contain a reference for the device dependent commands Contained is useful information for the remote operation of the modules The pages also contain the commands for only the LASERn current source The commands for the LASERn are identical merely replace LASER1 with 4 2 Note For 3916338 modules the n LASERn is not required L
45. d above The voltage limit also protects your laser by shutting off the source driver if the laser voltage exceeds the Vlim value The Vlim value should be set slightly above the operating voltage of the laser diode to provide maximum protection Note There is also a laser optical power limit Plim safety feature explained in this manual under the section titled Operating a Laser in Constant Power P Mode The laser optical power limit can be disabled by setting the CalPD value to zero on page 2 of the laser setup menu 09_07 LDC 3916330 Series 15 OPERATIONS Operating a Laser in Constant Current I Mode 4 Change the display to LAS p 3 of the laser setup menu to set the next parameter Do this by pushing the DOWN soft key F4 twice The Modulation parameter on this page controls whether the MODULATION connector input is active or not Select the Modulation parameter by pressing the DISPLAY UPIDOWN ARROW keys until the Modulation parameter is highlighted Adjust the value to ON or OFF as desired with the ADJUST UP DOWN ARROW keys or the ADJUST knob Refer to the LDC 3916330 Series Controller Module specifications for modulation input specifications and limitations Turning the Laser Current Source On Now you are ready to enable the current source output for your laser diode The top soft key F1 on any of the three pages of the LAS setup menu will toggle the laser current source on and off You can also turn t
46. de bias selection EON OKON o Parameters None The response is an lt nrf value gt Notes Photodiode bias is turned off when a RST command is issued Examples Laser1 BIAS response 0 means that the selected module s Laser1 photodiode bias is off 09 07 LDC 3916330 Series 39 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn CALPD DEVICE DEPENDENT FRONT PANEL The LASERn CALPD command sets the selected module s laser photodiode feedback responsivity the CAL PD parameter vore Parameters nrf value in microamps milliwatt uA MW Notes The module calculates optical power by dividing the monitor feedback current by its CALPD value Photodiode PD responsivity is frequently provided by manufacturers of packaged lasers with built in power monitors and is typically called Monitor Detector Responsivity The monitor produces a current when the laser illuminates it and this current will increase with increasing laser optical power Manufacturers of laser modules with integrated monitors may specify the responsivity of the monitor in terms of the laser optical power and the resulting monitor current Fox example a responsivity may be specified as 5 i A mW meaning that to produce a monitor current or 5 uA the laser optical power must be 1 mW Typically the specified responsivity is entered into the current source as CalPD using the LASERn CALPD command If this paramet
47. des of operation Examples LASER1 LIM V response 4 0 means the selected module s Laser1 voltage limit is 4 0 volts 09 07 LDC 3916330 Series 57 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn LIMit MDP DEVICE DEPENDENT FRONT PANEL The LASERn LIMit MDP command sets the laser optical power limit If the measured optical power exceeds this value the current source output will be shut off and a power limit error will be generated Parameters nrf value which represents the selected module s laser monitor photodiode power limit in mW Notes The monitor photodiode power limit condition normally shuts the output off but this can be disabled using the LASERn ENABIe OUTOFF command The laser optical power is a calculated value The module derives the optical power by dividing the monitor diode current MDI by CalPD The optical power limit is in effect for all operating modes with the following exceptions if CalPD is set to 0 0 the power is not calculated and the limit test is not performed The limit test is also not performed during calibration Examples LASER1 LIM MDP 200 action sets the selected module s Laser1 monitor photodiode power optical power limit to 200 mW LASERn LIMit MDP DEVICE DEPENDENT FRONT PANEL The LASERn LIMit MDP query returns the value of the selected module s laser optical power limit setpoint POP PO por Por Parameters None Th
48. diode current of laser 1 is displayed on line 1 of the status menu STATMENU LINE2 LDI response laser diode current of laser 2 is displayed on line 2 of the status menu STATMENU LINEn PPD SOMMON DEVICE DEPENDENT NT PANI FANE The STATMENU LINEn PPD command sets the measurement that is to be displayed on line n of the status menu to optical power PPD Ov SO Parameters None Notes Photodetector power is calculated via the CALPD conversion factor The measurement is only as accurate as the user s CALPD value Examples STATMENU LINE1 PPD response optical power is displayed on line 1 of the status menu STATMENU LINE2 PPD response optical power is displayed on line 2 of the status menu 72 7 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference bo STATMENU LINEn VF COMMON DEVICE DEPENDENT FRONT PANEL The STATMENU LINEn VF command sets the measurement that is to be displayed on line n of the status menu to laser diode forward voltage VF POT Oo SO Parameters None Examples STATMENU LINE1 VF response laser diode forward voltage of laser 1 is displayed on line 1 of the status menu STATMENU LINE2 VF response laser diode forward voltage of laser 2 is displayed on line 2 of the status menu 09 07 LDC 3916330 Series 73 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference 74 LDC 3
49. dule s laser constant current setpoint white nrf space value Parameters nrf value which represents the setpoint in mA Notes The setpoint is the same for both low and high bandwidth output modes The setpoint is read using the LASERn SET LDI query Examples Las LDI 400 action sets the selected module s Laser1 output current to 400 00 mA LASER1 Idi 100 action sets the selected module s Laser1 output current to 100 00 mA 54 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn LDI Cc DEVICE DEPENDENT FRONT PANEL The LASERn LDI query returns the value of the selected module s measured laser current vor t O pO Parameters None The response is an lt nrf value gt Notes Response is the selected module s measured LASERn output current regardless of control mode This measurement is updated approximately once every 600 msec Examples LASER1 Idi response 30 0 means the selected module s measured Laser1 output current is 30 0 mA LASER1 LDI response 149 6 means the selected module s measured Laser1 output current is 149 6 mA LASERn LDV OMMON DEVICE DEPENDENT FRONT PANEL The LASERn LDV query returns the value of the selected module s measured laser voltage Opt PO Parameters None The response is an lt nrf value gt Notes Response is the selected module s measured laser output
50. e E eaves 10 Four Wire Voltage Sense 10 Photodiode Connections 11 Grounding Considerations 11 Operating the Laser Current Source from the Front Panel 12 Operating a Laser in Constant Current I Mode 13 09 07 LDC 3916330Series i Ld n dM Entering the Laser Channel Setup Menu 13 Setting the Mode of Control 14 Setting the Current 14 Setting the Constant Current Value 15 Setting the Voltage 15 Enabling the Modulation Input 16 Turning the Laser Current Source 16 Operating a Laser in Constant Power P Mode 17 Calculating Photodiode Responsivity Values 17 Entering the Laser Channel Setup Menu 17 Selecting the Mode of Control 18 Setting the Current 19 Setting the Voltage 19 Setting the Power 20 Adjusting the Constant Power Setting
51. e laser diode voltage is about 0 25 volts below the VLim setting The open circuit condition occurs when the laser diode voltage is equal to or exceeds the VLim setting Examples LASER1 COND response 1027 means that the Laser1 output is on 1024 it is in voltage limit 2 and it is in current limit 1 LASER1 COND response 272 means that the Laser 1 output is shorted turned off 256 and its interlock pins are not connected 16 09 07 LDC 3916330 Series 45 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn DEC DEVICE DEPENDENT The LASERn DEC command decrements the selected module s laser constant current set point by one or more steps Parameters allow multiple steps to be decremented and the time in milliseconds between decrements to be set respectively lt white gt nrf Parameters Two nrf values are required The first one represents the number of steps and the second is the number of milliseconds between steps Notes The step size can be edited via the LASERn STEP command Its default value is 1 0 mA The first parameter number of steps must be an integer between 1 and 50000 The minimum time to complete one decrement is about 10 to 20 msec Therefore values for the second parameter time between decrements have a practical minimum of 20 The maximum number of msec is 65535 Only the LASERn LDI set point is decremented via this command regardless of m
52. e laser output to be enabled a short must exist between the Interlock pins pins 1 and 2 of the connector The short can be a direct short across the pins or a switch to prevent laser operation until the switch is closed If a short does not exist between these two pins and you attempt to turn on the LAS output an error will be indicated on the display for the respective channel on any of the Laser set up pages or on the status screen furthermore the output will be turned off The error is E401 if LAS1 s interlock is disconnected and the error is E501 if LAS2 s interlock is disconnected A CAUTION The interlock terminals on the LASER connector pins 1 and 2 must be kept isolated from all other connections including earth ground Four Wire Voltage Sense The LDC 3916330 Series Modules have a 4 wire voltage sense feature The laser voltage is sensed through a pair of connections pins 4 and 8 that is separate from the laser current drive connections pins 5 and 9 This allows a more accurate laser voltage reading for the voltage limit feature All four of these pins 10 7 LDC 3916330 Series Lightwave OPERATIONS Connecting to the Laser Current Source 4 5 8 9 must be connected for the module to operate See Tech Note TN3916 2 for more information on 4 wire Voltage Sense Photodiode Connections Many laser diode modules contain an internal photodiode that monitors the back facet emission of the laser Usually this
53. e response is an lt nrf value gt Examples LASER1 LIM MDP response 300 0 means the selected module s monitor PD power limit is set to 300 0 mW 58 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn MDI Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The LASERn MDI commands sets the selected module s laser monitor photodiode current setpoint white lt nrf space gt value gt An lt nrf value gt which represents the selected module s photodiode current setpoint in In constant monitor diode current MDI mode the output current is controlled so that the monitor diode current remains constant at the MDI setpoint See the LASERn Mode command for more information Monitor diode current is sometimes referred to as photodiode feedback current On the front panel monitor diode current is referred to as IPD Laser1 Mdi 40 action the selected module s Laser1 monitor photodiode current setpoint is set to 40 pA Laser1 MDI 200 5 action the selected module s Laser1 constant monitor photodiode current setpoint is set to 200 5 pA LASERn MDI Parameters Notes Examples 09 07 DEVICE DEPENDENT FRONT PANEL The LASERn MDI query returns the value of the selected module s laser photodetector monitor photodiode current measurement in None The response is an
54. ecting laser diodes and photodiodes with the LDC 3916330 Series Laser Diode Controller Modules OUTPUT Module Earth Ground Figure 2 1 Common Laser Cathode Photodiode Cathode 8 7 LDC 3916330 Series Lightwave OPERATIONS Connecting to the Laser Current Source Module OUTPUT Earth Ground Figure 2 2 Common Laser Cathode Photodiode Anode OUTPUT Module Earth Ground Figure 2 3 Common Laser Anode Photodiode Cathode OUTPUT Module Earth Ground Figure 2 4 Common Laser Anode Photodiode Anode 09_07 LDC 3916330 Series 9 OPERATIONS Connecting to the Laser Current Source Connectors on the rear panel of the LDC 3916330 Series modules provide laser anode and cathode photodiode anode and cathode chassis ground interlock and laser forward voltage connections pin out diagram for these connectors is shown in Figure 2 2 The LDC 3916332 and LDC 3916334 modules are dual current source modules and have two 9 pin connectors one for each laser source The top connector is for the current source called LAS1 while the bottom connector is for the current source called LAS2 1 2 Interlock es 3 Chassis Ground e o 4 Cathode Voltage Sense e 5 Laser Cathode e ud Ls 6 PD Cathode e 7 PD Anode 2 E 8 Anode Voltage Sense 4 e 9 Laser Anode Figure 2 5 Back Panel LD Connector Interlock Connections In order for th
55. er is set to 0 the module will not calculate the optical power It will display on the front panel and GPIB queries of the optical power using the LASERn MDP query will return 1 0 Examples LASER1 CALPD 0 action sets the CAL PD parameter to 0 Laser1 Calpd 10 0 action sets the CAL PD parameter to 10 0 microamp milliwatt A photodiode feedback current of 10 uA will cause the measured optical power to be 1 milliwatt LASERn CALPD DEVICE DEPENDENT FRONT PANEL The LASERn CALPD query returns the value of the selected module s laser photodiode feedback responsivity CalPD parameter setting Parameters None The response is nrf value Notes If this value is 0 the front panel Ppd will display and measured optical power read with GPIB using the Laser1 mdp query will be 1 0 Examples LASER1 CALPD response 1 1 means the selected module s Laser1 CalPD is set to 1 10 uA mW a photodiode feedback current of 2 2 uA represents 2 mW of optical power 40 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn CAL COMMON DEVICE DEPENDENT FRONT PANEL The LASERn CAL command path is used to get to the selected module s laser calibration commands The following commands may be reached directly from the LASER CAL command path LASERn CAL ABORT LASERn CAL DEFAULT LASERn CAL LDI LASERn CAL LDV LASERn CA
56. er mode selection commands The following commands may be reached directly from the LASERn MODE command path LASERn MODE IHBW LASERn MODE ILBW LASERn MODE MDI LASERn MODE MDP 09 07 LDC 3916330 Series 61 62 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn MODE IHBW COMMON Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The LASERn MODE IHBW command selects high bandwidth constant current mode for the selected module s laser current source None In high bandwidth mode the modulation bandwidth is increased Laser1 mode ihbw action enables the high bandwidth constant current mode for the selected module s Laser1 current source LASERn MODE ILBW Parameters Notes Examples LDC 3916330 Series DEVICE DEPENDENT FRONT PANEL The LASERn MODE ILBW command selects low bandwidth constant current mode for the selected module s laser current source Op eoo None Constant ILBW mode low bandwidth enables the selected module s output low bandpass filter Laser1 mode ilbw action enables the low bandwidth constant current mode for the selected module s Laser1 current source Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn MODE MDI Cc DEVICE DEPENDENT FRONT PANEL The LASERn MODE MDI command selects constant monitor diode current MDI mode for the selected module s laser cur
57. errors MODERR NONE Returns module errors generated since the last error query to LIEN LEN EDEN pu LASER ooo Sets the constant current source set point po Command Timing and Completion All commands for the LDC 3916330 Series modules are sequential except for the LAS OUT LAS INC and LAS DEC commands LAS OUT command is overlapped to allow the user to abort it with the LAS OUT OFF command during a two second interval after the output is told to be on The LAS INC and LAS DEC commands are overlapped to allow the user to monitor the other functions while in an automatic ramping mode For more information on the use of operation complete commands such as WAI and OPC refer to the LDC 3916 User s Manual Chapter 3 09 07 LDC 3916330 Series 27 REMOTE OPERATIONS Status Reporting Status Reporting Refer to the LDC 3916 Laser Diode Controller Instruction Manual Chapter 3 Operating in Remote Control for information on standard status structures mainframe related commands and for understanding the Operation Complete definition The following sections discuss the LDC 3916330 Series module dependent aspects of the status reporting including the OUTOFF commands and queries The Output Off Register section also contains information on specifying some of the conditions that will force the laser current source and or TEC output off Status Registers The LDC 3916330 Serie
58. eys F3 and F4 while in the setup menu Which parameter to adjust can be selected with the DISPLAY UP DOWN ARROW keys In general the selected parameter value can be adjusted with the numeric keypad the ADJUST knob or the ADJUST UP DOWN ARROW keys The ENTER key must be pressed within three seconds after entering a numeric value with the keypad or the value will revert to the previous value The DISPLAY is used to show both the set point and measured value of laser control parameters such as laser drive current Iset and lo laser current limit Ilim laser forward voltage Vf forward voltage limit Vlim mode of control Mode monitor photodiode current Ipdset and and laser optical power Plim and It will also display error codes which relate to LASER operation Error codes indicate control errors and are explained below in the section titled LASER ERROR INDICATORS The following sections describe fundamentals of single channel operation for your LDC 3916330 Series Laser Diode Current Sources in two operating modes Constant Current I and Constant Power P 12 8 LDC 3916330 Series uix Lightwave OPERATIONS Operating a Laser in Constant Current I Mode Operating a Laser in Constant Current I Mode Suppose you have an LDC 3916330 Series Module and you want to run the instrument in Constant Current low bandwidth mode Ilbw with a set point of 150 mA a current limit of 175 mA and a voltage limit of 6
59. h at least 3 inches 7 5 cm of compressible packaging material on all sides We look forward to serving you even better in the future x 7 LDC 3916330 Series Lightwave CHAPTER INTRODUCTION AND SPECIFICATIONS El E El a El mH mH El El El B E El E This chapter is an introduction to the LDC 3916330 Series Laser Diode Current Source Modules for use in the LDC 3908 LDC 3916 and LDC 3926 LD Controller Mainframes It covers model numbers LDC 3916332 500 mA Dual Current Source Module LDC 3916334 1A Dual Current Source Module and LDC 3916338 Single Current Source Module Chapter 1 contains unpacking information instructions on how to install and apply power and safety considerations and instructions It also contains some maintenance information and specifications warnine If any of the following symptoms exist or are even suspected remove the LDC 3916330 Series Controller Module from service Do not use the modules until safe operation can be verified by trained service personnel Visible damage Severe transport stress Prolonged storage under adverse conditions Failure to perform intended measurements or functions If necessary return the modules to ILX Lightwave for service and repair to ensure that safety features are maintained Safety Symbols and Terms The following safety terms are used in this manual The WARNING heading explains dangers that could result in personal injury or death
60. he LASER output terminals Laser Anode pin 9 and Laser Cathode pin 5 Current will flow from the anode to the cathode The top 9 pin connector on the back of the module is for LAS1 and the bottom 9 pin connector is for LAS2 Connect a calibrated DMM across the load resistor You will be calculating laser current LDI in the following manner using Ohm s Law E R where E is the accurately measured voltage across the resistor and R is the accurately measured load resistance a 4 point probe resistance measurement is recommended is the calculated current in Amps Note We recommend that the load resistor be temperature controlled during the calibration Alternatively the current may be measured directly using an ammeter with a range of at least 2 A and accurate to 0 001 mA If you use the ammeter approach you should connect the ammeter in series with a load resistor with a nominal value of 10 Enter the LDI calibration mode by pushing the DISPLAY MAIN front panel button then the SYS CONFIG soft key then the CAL soft key For the 3916332 or 3916334 modules press Cal LAS1 or Cal LAS2 to choose which source to calibrate on the dual current source modules or Cal LAS for the 3916338 module single current source module Then press the LDI Cal soft key the module s LDI calibration screen will appear Press the Start soft key The internal calibration procedure will turn on the output and drive the LD current to approximately 2
61. he Laser output current to approximately 25 of its full range Allow the current to settle for at least 10 seconds If this calibration value is to be measured and entered remotely via a GPIB controlled DMM for example the actual value of the current should not be entered until the cal procedure is ready to receive it 5 Check to see if the internal cal procedure is ready for the measurement Send the following query LASERn CAL STATUS The cal procedure is ready for a measurement if it returns the value 1 Query the status until the value that is returned is 1 6 Enter the measured voltage in Volts by sending the following command LASERn CAL MEAS voltage in Volts e g LASER1 CAL MEAS 3 76 7 Thecal procedure will set the output current to approximately 75 of its output range Allow the current to settle for at least 10 seconds 8 Check to see if the internal cal procedure is ready for the measurement Send the following query to the module LASERn CAL STATUS The cal procedure is ready for a measurement if it returns the value 1 Query the status until the value that is returned is 1 9 Enter the second measured voltage in Volts by sending the following command LASERn CAL MEAS voltage in Volts e g LASER1 CAL MEAS 11 24 09 07 LDC 3916330 Series 85 TROUBLESHOOTING Remote Calibration of the LDC 3916330 Dual Current Source Module After you have entered the second measured voltage the internal calibration
62. he current source on and off with the top soft key F1 on the CHAN menu The ON toggle has a two second delay before the current source is enabled in compliance with safety requirements Each current source can be turned on or off independently as described above or you can turn on all the channels at the same time from the All Chnl menu See the LDC 3908 LDC 3916 or LDC 3926 Mainframe Instruction Manual for more information on the all channel operation 16 7 LDC 3916330 Series Lightwave OPERATIONS Operating a Laser in Constant Power P Mode Operating a Laser in Constant Power P Mode Suppose you want to operate a 3 mW laser in constant optical power at 1 mW The LDC 3916330 Series Controller Modules allow you to operate the instrument current source drivers in Constant Optical Power P mode In the P mode the controller drives current to the laser to reach a set power value in mW The control loop feedback parameter is monitor photodiode current which the controller converts to optical power via a user defined photodiode responsivity number CalPD If laser power changes due to internal or environmental conditions the controller will increase decrease the current to the laser to maintain the power set point The following paragraphs detail the instrument configuration in Constant Power Mode Calculating Photodiode Responsivity Values The photodiode responsivity CalPD is used to convert between photodiode curren
63. he figure This ammeter is in series with the Photodiode Anode input to the module and directly measures the photodiode current 3 Enter the Laser Current Source calibration mode by sending the following command over GPIB LASERn CAL MDI 4 The internal cal procedure will turn on the output and drive the laser current until the PD current is approximately 15 of full range Allow the current to settle for at least 10 seconds If this calibration value is to be measured and entered remotely via a GPIB controlled DMM for example the actual value of the current should not be entered until the cal procedure is ready to receive it 5 Check to see if the internal cal procedure is ready for the measurement Send the following query to the module LASERn CAL STATUS The cal procedure is ready for a measurement if it returns the value 1 Query the status until the value that is returned is 1 6 Enter the measured current in pA by sending the following command LASERn CAL MEAS current in uA e g LASER1 CAL MEAS 745 321 7 controller will drive the laser current until the PD current to approximately 65 of full range Allow the current to settle for at least 10 seconds 8 Check to see if the internal cal procedure is ready for the measurement Send the following query to the module LASERn CAL STATUS The cal procedure is ready for a measurement if it returns the value 1 Query the status until the value that is returned
64. he instrument under laboratory conditions We recommend calibration at 23 C 1 0 C When necessary however the 3916330 Series Module may be calibrated at its intended use temperature if this is within the specified operating temperature range of 0 to 40 C Recommended Equipment Recommended test equipment for calibrating the 3916330 Series Laser Diode Controller module is listed in Table 5 1 Equipment other than that shown in the Lightwave LDC 3916330 Series 75 TROUBLESHOOTING Calibration Overview table may be used if the specifications meet or exceed those listed Table 5 1 Recommended Test Equipment Description Mfg Model Specification DMM HP 3457A DC Amps 1 0A 0 02 Resistance 9 10 0 02 0 1 or 0 1 mV resolution It will be necessary to connect various loads and circuits to the outputs of the module for the calibration procedure The devices required for most of the calibration loads are listed in Table 5 2 A schematic is shown in Figure 5 1 for the photodiode calibration circuit with the required components listed in Table 5 3 Table 5 2 Required Calibration Components LASER CURRENT SOURCE CALIBRATION Current Source Calibration 10 20W resistor low TCR Voltage Measurement Calibration 3916332 334 15Q 20W resistor low TCR Voltage Measurement Calibration 3916338 50W resistor low TCR PHOTODIODE MONITOR CALIBRATION See schematic in Figure 5 1
65. ime to this query is from 200 msec to 250 msec but the measurement is made as soon as the query is received In contrast the LASER mdp query returns immediately but the measurement can be up to 600 msec old Examples LASER1 syncmdp response 5 5 means the calculated optical power is 5 5 mW STATMENU LINEn DEVICE DEPENDENT The STATMENU LINE n command path is used to get to the selected channel s status menu display selection commands n can be either 1 or 2 Line 1 only displays measurement from laser source 1 and line 2 displays measurements from laser source 2 The following commands may be reached directly from the STATMENU LINE n command path STATMENU LINEn IPD STATMENU LINE r LDI STATMENU LINEn PPD STATMENU LINEn VF 70 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference STATMENU LINEn COMMON DEVICE DEPENDENT The STATMENU LINEn query returns the name of the measurement that is currently being displayed on line n of the status menu n can be either 1 or 2 o LO Parameters None The response is character data which represents the measurement that is currently being displayed on line 1 of the selected channel s portion of the status menu Notes The possible responses are 1 LDI LASER diode current 2 IPD photodiode current 3 PPD optical power 4 VF LASER diode forward voltage The default condition
66. imit 256 Output Shorted 2 Voltage Limit 512 Output In Tolerance 4 N A 1024 Output On 8 Power Limit 2048 N A 16 Interlock Disabled 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit 32768 N A Notes This register be read using the LASERn ENABle COND query See the Status Reporting section of the 3916 manual for more information regarding condition reporting Examples LASER1 ENAB COND 9 action the only conditions from the selected module that will be reported to the 3916 status byte are the power limit 8 and current limit 1 conditions 09 07 LDC 3916330 Series 47 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn ENAB1le COND COMMON DEVICE DEPENDENT FRONT PANEL The LASERn ENABle COND query returns the value of the selected module s laser condition status enable register POP Parameters None The response is the sum of the following 1 Current Limit 256 Output Shorted 2 Voltage Limit 512 Output In Tolerance 4 N A 1024 Output On 8 Power Limit 2048 N A 16 Interlock Disabled 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit 32768 N A Notes The selected module s enabled laser conditions can be set by using the LASERn ENABle COND command The laser condition status can be monitored by the LASERn COND query Examples LASER1 ENAB COND response 258 means that only the follo
67. ion Note Be sure to push the ENTER key within three seconds after using the keypad to adjust any numeric values in the setup menus otherwise the value will revert to the previous setting Setting the Power Limit Now push the DOWN soft key F4 to advance to LAS p 2 of the laser setup menu Before the laser is enabled the power limit for the laser under test should be set To do this push the DISPLAY UP DOWN ARROW keys to select the power limit Plim parameter Adjust this value to your desired laser optical power limit The responsivity value CalPD must be set to the correct value for the power limit feature to work properly This is a software limit only The LASER output is normally turned off if this limit is reached Adjusting the Constant Power Setting 9 ecc Manr Use the DISPLAY UP DOWN ARROW keys to select the power Pset parameter and adjust the value to 1 mW The Controller Module will divide the measured photodiode current by the CalPD value to calculate the laser optical power The current source will automatically adjust the laser drive current to keep the calculated laser power at the Pset value 20 7 LDC 3916330 Series Lightwave OPERATIONS Operating a Laser in Constant Power P Mode Setting the Responsivity Value CalPD Im m m mtn 8 8 0 8 LB T m m The correct responsivity value CalPD must be set for the constant power mode to operate properly
68. ion to unsigned 32 bit integer Error in conversion to floating point number Error in conversion to character pointer Error in conversion to byte pointer Response is too long to output Set value is over range Set value is under range Error in arbitrary block specification LDC 3916330 Series 33 o REMOTE OPERATIONS E Error Messages Error Code Explanation E 401 Interlock Open forces Laser 1 output off E 403 Laser 1 Voltage Limit forces output off Open Circuit error E 404 Laser 1 Current Limit forces output off E 405 Laser 1 Voltage Limit forces output off E 407 Laser 1 Monitor Diode Power Limit forces output off E 408 External TEC Output Off Status forces LASI output off E 409 External TEC Temperature Limit forces LAS1 output off E 410 Out of Tolerance status forced LAS1 output off E 411 Laser 1 Hardware Error forces output off e g low power line voltage E 429 Laser 1 Output is off but Laser 1 Status thought it was on E 435 Laser 1 Mode changed while output on E 501 Interlock Open forces Laser 2 output off E 503 Laser 2 Voltage limit forces output off Open Circuit error E 504 Laser 2 Current Limit forces output off E 505 Laser 2 Voltage Limit forces output off E 507 Laser 2 Monitor Diode Power Limit forces output off E 508 External TEC Output Off Status forces LAS2 output off E 509 External TEC Temperature Limit forces LAS2 output off E 510 Out of Tolerance status forced
69. is 1 09 07 LDC 3916330 Series 83 TROUBLESHOOTING Remote Calibration of the LDC 3916330 Dual Current Source Module 9 Enter the measured current in uA by sending the following command LAS CAL MEAS current in pA e g LAS CAL MEAS 3573 344 After you have entered the second measured photodiode current the internal calibration procedure will perform the calibration for the photodiode current measurement circuit The cal procedure will then set the status to the value 2 to indicate that it has finished 84 LDC 3916330 Series uix Lightwave TROUBLESHOOTING Remote Calibration of the LDC 3916330 Dual Current Source Module Laser Forward Voltage Measurement Calibration The following procedure is for remotely calibrating the laser forward voltage measurement circuit The module s internal calibration procedure sets the current to two values You must measure and enter the forward voltage at both of these points The module s internal cal procedure will then use this information to calibrate the voltage measurement system 1 With the output off connect the specified load resistor see Table 5 2 across the LASER output Laser Anode pin 9 and Laser Cathode pin 5 2 calibrated voltmeter across the load resistor plus lead to Anode 3 Enter the Laser voltage measurement calibration mode by sending the following command over GPIB LASERn CAL LDV 4 Theinternal cal procedure will begin by setting t
70. k to the factory for repair be sure that the module is packages in an anti static bag and an enclosure with cushioning material to prevent damage to the module during shipment use the original shipping containers and accessories if possible Re install the ESD protective caps on the rear panel over the 9 pin connector Shipping damage is not covered under warranty Attach to the module a copy of the completed service form see Safety and Warranty section We suggest that you insure the shipment 09 07 LDC 3916330 Series 3 INTRODUCTION AND SPECIFICATIONS Specifications Specifications The following specifications are for when the modules are used in the LDC 3916 16 Channel Laser Diode Controller Mainframe or the LDC 3908 8 Channel Laser Diode Controller Mainframe Please see the LDC 3926 16 Channel High Power Laser Diode Controller Mainframe brochure for specifications when the modules are used in the LDC 3926 MODEL NUMBER 3916332 Dual 500mA 3916334 Dual 1A 3916338 Single 3A DRIVE CURRENT OUTPUT Output Current Range 0 to 500 mA 0 to 1000 mA 0 to 3000 mA Set Point Resolution 10 pA 20 pA 80 pA Set Point Accuracy Compliance Voltage 0 1 of full scale 6 V maximum adjustable voltage limit X 0 1 of full scale 6 V maximum adjustable voltage limit 0 196 of full scale 2 4 5 V adjustable voltage limit Temperature Coefficient lt 50 ppm C lt 50 ppm C lt 100 ppm C Short Term Stability 1 hr lt 20 ppm
71. l Shipping Instructions If you need to ship your LDC 3916330 Series Laser Diode Controller Module back to the factory for repair be sure that the module is packaged in an anti static bag and an enclosure with cushioning material to prevent damage to the module during shipment use the original shipping containers and accessories if possible Re install the ESD protective caps on the rear panel over the 9 pin connectors Shipping damage is not covered under warranty Attach a tag to the module identifying the owner and indicating the service or repair needed Include the model number serial number and return authorization number We suggest that you insure the shipment See your mainframe manual for instructions on where to ship the module Calibration and Repair Services You may have to return your current source module to an ILX Lightwave facility at some time for repair calibration or service whether it is under warranty or not There is a charge for repairs after the warranty period has expired Contact an ILX Lightwave service representative for shipping instructions prior to returning the instrument Have the above information available when you call A return authorization number will be given to you at the time of your request for repair or service Please use this number in all communications concerning your instrument General Shipping Instructions If you need to ship your LDC 3916330 Series Laser Diode Current Source Module bac
72. module LASERn CAL STATUS The cal procedure is ready for a measurement if it returns the value 1 Query the status until the value that is returned is 1 9 Enter the second measured current in mA by sending the following command LASERn CAL MEAS current in mA e g LASER1 CAL MEAS 527 986 After you have entered the second measured current the internal calibration procedure will perform the calibration for the laser current setpoint current measurement and current limit circuits The cal procedure will then set the status to the value 2 to indicate that it has finished LDC 3916330 Series Lightwave TROUBLESHOOTING Remote Calibration of the LDC 3916330 Dual Current Source Module IPD Current Calibration The following procedure is for remotely calibrating the LASER lpp photodiode monitor measurement circuit The module s internal calibration procedure sets the current to two values You must enter the resulting lpp photodiode monitor current that you measure at both of these points The module s internal cal procedure will then use this information to calibrate the Ipp measurement circuit The GPIB commands use the nomenclature MDI which means Monitor Diode Current and is synonymous with IPD 1 With the output off connect the IPD calibration circuit Figure 5 1 to the appropriate laser connector 2 Connect an ammeter with at least 5000 uA range and at least 0 1 uA accuracy as shown in t
73. n has high output Check the photodiode bias If it is off the circuit may act current but little or no power is measured as an open feedback loop Set the bias to on 5V Output exceeds power limit It is possible via GPIB to disable turning off the output when the power limit is exceeded Ensure that this is not the case Default at power up is to enable this safety feature The Power Limit is not a hardware limit It serves as a warning that the power measurement has exceeded the limit set point Open Circuit Error occurs during Check load connections Check that measuring meter calibration does not auto range use non auto ranging modes Calibration is aborted unintentionally Calibration modes will be aborted if an open circuit is detected or if entered measurements are invalid 88 LDC 3916330 Series Lightwave
74. nsient resulting from a 1000V power line transient spike Tested to ILX Lightwave Technical Standard LDC 00196 Request ILX Application Note 3 Maximum monitor photodiode current drift over any 30 minute period Assumes zero drift in responsivity of photodiode Modulation input is 50 Q terminated inside the mainframe 250 mA set point 50 mA modulation current 1Q load High bandwidth mode 50 modulation at mid scale output 10 load High bandwidth mode Responsivity value is user defined and is used to calculate the optical power Four wire voltage measurement Voltage measurement accuracy while driving calibration load Accuracy is dependent upon load and cable used In keeping with our commitment to continuing improvement ILX Lightwave reserves the right to change specifications without notice or liability for such changes 09 07 LDC 3916330 Series 5 INTRODUCTION AND SPECIFICATIONS Specifications 6 7 LDC 3916330 Series Lightwave CHAPTER OPERATIONS E El w a E El E B Ej a This chapter introduces you to the operation of the LDC 3916330 Series Dual LD Current Source s control functions It offers instructions for connecting your lasers to the current sources This chapter also contains step by step procedures that teach you how to operate your module in Constant Current Mode or Constant Power Mode We recommend that you review the contents of this chapter at a minimum before operating your new LDC 3916
75. nt is made and the result is returned as the response After the measurement is made the measurement system returns to its normal function switching between the various signals and measuring them The response time to this query is from 200 msec to 250 msec but the measurement is made as soon as the query is received In contrast the LASER mdi query returns immediately but the measurement can be up to 600 msec old Examples LASER1 syncmdi response 145 5 means the measured photodiode current is 145 5 uA J 09 07 LDC 3916330 Series 69 4 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn SYNCMDP DEVICE DEPENDENT LASERn SYNCMDP query returns the value of the selected channel s measured optical power in mW O gt Parameters None The response is an lt nrf value gt representing optical power in mW Notes Optical power is derived from photodiode current Optical power is defined as photodiode current divided by CalPD the photodiode responsivity This is a synchronized measurement the measurement system is connected to the monitor current measure signal when this query is received The photodiode current measurement is made optical power is calculated and the result is returned as the response After the measurement is made the measurement system returns to its normal function switching between the various signals and measuring them The response t
76. ode setting or output status Examples LASER1 STEP 0 3 LASER1 DEC 1 100 action the Laser1 constant current setpoint is decremented by 0 3 mA LASER1 STEP 0 5 LASER1 DEC 4 100 action the step size is set to 0 5 mA the setpoint is decremented by 4 steps of 0 5 mA separated in time by 100 msec for a total decrement of 2 0 mA laser1 step 1 0 laser1 dec 10 1000 action the step size is set to 1 0 mA the setpoint is decremented by 1 0 mA 10 times with 1 second between decrement steps The Laser1 output is decremented a total of 10 mA over a period of 10 seconds LASERn ENABle DEVICE DEPENDENT The LASERn ENABle command path is used to get to the selected module s laser status enable commands and queries The following commands be reached directly from the LASER1 ENABle command path LASERn ENABle COND LASERn ENABle EVEnt LASERn ENABle COND LASERn ENABle OUTOFF LASERn ENABle EVEnt LASERn ENABle OUTOFF 46 LDC 3916330 Series uix Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn ENABl1le COND COMMON DEVICE DEPENDENT FRONT PANE The LASERn ENABle COND command sets the selected module s laser condition status enable register The bits in this register determine which bits in the Laser1 condition status register are summarized in the 3916 status byte Parameters nrf value whose sum represents the enabled bits 1 Current L
77. ode changed Operating mode of the module was changed while output while the laser output enabled enabled LDC 3916330 Series Lightwave CHAPTER 3 REMOTE OPERATIONS El a gl El w E Li mH E El Everything you do from the front panel can also be done remotely and in some cases with more flexibility For example in remote mode you can enable or disable conditions that will cause the laser current source or the TEC controller to automatically shut off The following sections show you the fundamentals of operating your LDC 3916330 Series module remotely through the GPIB and RS 232 interfaces Remote Configuration Refer to the LDC 3916 Instruction Manual Chapter 3 Operating in Remote Control for information concerning setup of GPIB or RS 232 remote communications That section also describes the use of IEEE 488 2 common commands LDC 3916 mainframe commands and syntax LDC 3916330 Series Laser Diode Controller Command Set The LDC 3916330 Series module utilizes its own module specific commands as well as the commands for the LDC 3916 mainframe see LDC 3916 User s Manual Chapter 3 Operating in Remote Control Figure 3 1 shows all of the commands which are usable by the LDC 3916 in conjunction with the LDC 3916330 Series modules Lightwave LDC 3916330 Series 25 LDC 3916330 Series Laser Diode Controller Command Set 00 LDC 9916330 Series Laser Dio C
78. ommand Reference LASERn STEP DEVICE DEPENDENT The LASERn STEP query is used to read back the selected module s laser setpoint step size This value is the amount the setpoint will change in response to a LASERn Inc or LASERn Dec command Parameters None The response is an lt nrf value of the selected module s step amount Notes The step of 1 corresponds to 1 0 mA Examples Laser1 Step response 1 0 means the selected module s Laser1 step size is 1 0 mA LASERn SYNCLDI DEVICE DEPENDENT The LASERn SYNCLDI query returns the value of the selected channel s measured laser current in mA O gt Parameters None The response is an lt nrf value gt representing current in mA Notes This is a synchronized measurement the measurement system is connected to the current measure signal when this query is received A current measurement is made and the result is returned as the response After the measurement is made the measurement system returns to its normal function switching between the various signals and measuring them The response time to this query is from 200 msec to 250 msec but the measurement is made as soon as the query is received In contrast the laser ldi query returns immediately but the measurement can be up to 600 msec old Examples LASER1 syncldi response 54 1 means the measured LASER current is 54 1 mA 68 LDC 3916330 Series Lightwave
79. ource calibration of the laser forward voltage LDV measurement and calibration of the constant light power lpp feedback circuit LDI Calibration The following procedure is for remotely calibrating the laser current sources The module s internal calibration procedure sets the current to two values You must measure and enter the exact Laser Diode current at both of these points The module s internal cal procedure will then use this information to calibrate the current source 1 With the output off connect a 19 20 W resistor across the LASER output terminals Laser Anode pin 9 and Laser Cathode pin 5 The top 9 pin connector on the back of the module is for LAS1 and the bottom 9 pin connector is for LAS2 2 Connect a calibrated DMM across the load resistor You will be calculating laser current LDI in the following manner using Ohm s Law E R where E is the accurately measured voltage across the resistor and R is the accurately measured load resistance a 4 point probe resistance measurement is recommended is the calculated current in Amps Note We recommend that the load resistor be temperature controlled during the calibration Alternatively the current may be measured directly using an ammeter with a range of at least 2 A and accurate to 0 001 mA If you use the ammeter approach you should connect the ammeter in series with a load resistor with a nominal value of 10 3 Enter the Laser Current Source calibra
80. r The Constant Photodiode Current Ipd mode will control the laser drive current so the monitor photodiode current remains at a constant set point To do this adjust the Mode on LAS p 1 of the laser setup menu and set the photodiode current Ipdset parameter on the LAS p 2 menu to your desired value In this case you may want to set the power limit Plim value high or set CalPD to zero which will disable the power limit feature Turning the Laser Current Source On Now this channel is configured to operate in Constant Power Mode The Controller s laser current source will drive the laser to the Constant Power set point and maintain closed loop control with the monitor photodiode current measurement You can enable this channel now or set all of the other channels first The top soft key F1 on any of the three pages of the LAS setup menu will toggle the laser current source on and off You can also turn the current source on and off with the top soft key F1 on the channel menu The ON toggle has a two second delay before the current source is enabled in compliance with safety requirements Each current source can be turned on or off independently as described above or you can turn on all 16 channel sources at the same time from the All Chnl menu See the LDC 3908 LDC 3916 or LDC 3926 Mainframe Instruction Manual for more information on all channel operation 22 7 LDC 3916330 Series uix Lightwave OPERATIONS Conditions
81. r all modes of operation Examples LASER1 LIM 1 response 40 means the selected module s Laser1 current limit is 40 mA Laser1 LIM I response 300 means the selected module s Laser1 current limit is 300 mA 56 LDC 3916330 Series Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn LIMit V COMMON DEVICE DEPENDENT FRONT PANEL LASERn LIMit V command sets the selected module s laser voltage limit VLim value If the laser diode voltage exceeds this value the output will automatically turn off and an open circuit error will be generated Parameters nrf value which represents the selected module s laser limit voltage in volts Notes Voltage limit is in effect in all modes of operation If the laser diode voltage exceeds this value the current source will automatically turn off and generate an open circuit error The range for the voltage limit is 0 1 to 7 5 volts Examples LASER1 LIM V 4 6 action the selected module s Laser1 voltage limit is set to 4 6 volts Laser1 Limit v 6 1 action the selected module s Laser1 voltage limit is set to 6 1 volts LASERn LIMit V DEVICE DEPENDENT FRONT PANEL LASERn LIMit V query returns the value of the selected module s laser voltage limit setpoint A A PO Parameters None The response is an nrf value Notes The selected module s voltage limit is valid for all mo
82. r to ensure that safety features are maintained see the contact information on page x All instruments returned to ILX Lightwave are required to have a Return Authorization Number assigned by an official representative of ILX Lightwave Corporation See Returning an Instrument on page ix for more information Lightwave LDC 3916330 Series vii SAFETY SYMBOLS This section describes the safety symbols and classifications Technical specifications including electrical ratings and weight are included within the manual See the Table of Contents to locate the specifications and other product information The following classifications are standard across all ILX Lightwave products Indoor use only Ordinary Protection This product is NOT protected against the harmful ingress of moisture Class Equipment grounded type Mains supply voltage fluctuations are not to exceed 10 of the nominal supply voltage Pollution Degree 2 Installation overvoltage Category II for transient overvoltages Maximum Relative Humidity lt 80 RH non condensing Operating temperature range of 0 xC to 40 xC Storage and transportation temperature of 40 xC to 70 xC e Maximum altitude 3000 m 9843 ft This equipment is suitable for continuous operation Safety Marking Symbols This section provides a description of the safety marking symbols that appear on the instrument These symbols provide information
83. rameters Function LAS MODE NONE Returns the mode current IHBW high bandwidth P optical power or MDI constant monitor current LAS MODE IHBW NONE Sets the mode to constant current high bandwidth LAS MODE ILBW NONE Sets the mode to constant current low bandwidth mode LAS MODE MDP NONE Sets the mode to constant optical power mode LAS MOD 1 Enables or disables the channel s modulation output LAS MOD NONE Returns the status of the channel s modulation output LAS OUT 1 Enables disables the current source output LAS OUT NONE Returns the current source output status LAS SET LDI NONE Returns the LASER constant current set point LAS SET MDI NONE Returns the LASER constant optical power set point LAS SET MDP NONE Returns the constant P optical power set point LAS STEP 1 Sets the LASER set point step value LAS STEP NONE Returns the LASER set point step value LAS SYNCLDI NONE Synchronized measurement returns the LASER current in mA LAS SYNCLDV NONE Synchronized measurement returns the LASER voltage in volts LAS SYNCMDI NONE Synchronized measurement returns the monitor photodiode current in pA LAS SYNCMDP NONE Synchronized measurement returns the optical power LAS TOL 2 Sets the LASER set point tolerance value and time period value LAS TOL NONE Returns the LASER set point tolerance value and time period value MODERR NONE Returns the error codes up to 10 from the module MODIDN NONE Returns identification d
84. rce or to the LASER current source To send command to LASER 1 replace LASERn with LASER1 LASER will cause command to go to LASER2 Lightwave LDC 3916330Series 35 4 COMMAND REFERENCE Table 4 1 GPIB Command Summary Reference List Name Parameters Function LAS BIAS 1 Enables or disables the 5 volt photodiode bias LAS BIAS NONE Returns the status of the photodiode bias control LAS CALPD 1 Used to set the CAL PD monitor responsivity constant LAS CALPD NONE Returns the CAL PD monitor responsivity constant LAS CAL ABORT NONE Aborts a calibration LAS CAL DEFAULT NONE Restores all calibration values to their defaults LAS CAL LDI NONE Enters the LASER current calibration mode LAS CAL LDV NONE Enters the LASER voltage calibration mode LAS CAL MDI NONE Enters the monitor photodiode current calibration mode LAS CAL MEAS 1 Enters a calibration value LAS CAL STAT NONE Returns a value which represents the calibration status LAS CAL VALUE 1 Used for factory calibration testing only LAS COND NONE Returns the value of the LASER condition register LAS DEC 2 Decreases the LASER set point value by one or more steps with user programmable delay between steps LAS ENAB COND 1 Sets the enable register for LASER conditions LAS ENAB COND NONE Returns the value of the LAS conditions enable
85. register LAS ENAB EVE 1 Sets the enable register for LAS events LAS ENAB EVE NONE Returns the value of the LAS event enable register LAS ENAB OUTOFF 1 Sets the enable register for LAS conditions which turn the LAS output off LAS ENAB OUTOFF NONE Returns the value of the LAS outoff enable register LAS EVE NONE Returns the value of the LAS event register LAS LDI 1 Sets the LASER constant current source set point value LAS LDI NONE Returns the constant current source measured value LAS INC 2 Increases the LASER set point value by one or more steps with user programmable delay between steps LAS LDV NONE Returns the measured LASER voltage value LAS LIM I 1 Sets the LASER current source limit LAS LIM I NONE Returns the LASER current source limit LAS LIM MDP 1 Sets the constant optical power from monitor PD limit value LAS LIM MDP NONE Returns the optical power from monitor PD limit value LAS LIM V 1 Sets the LASER compliance voltage limit value LAS LIM V NONE Returns the LASER compliance voltage limit value LAS MDI 1 Sets the monitor current set point LAS MDI NONE Returns the monitor PD current measured value LAS MDP 1 Sets the constant optical power set point LAS MDP NONE Returns the actual monitor PD power value LDC 3916330 Series Lightwave COMMAND REFERENCE Table 4 1 GPIB Command Summary Reference List Name Pa
86. rent source Parameters Notes On the front panel constant monitor diode current mode is referred to as IPD mode In this mode the control set point is entered with the LASn MDI command Examples Laser1 Mode MDi action sets the selected module s LASER1 operating mode to constant monitor diode current mode LASERn MODE MDP COMMON DEVICE DEPENDENT FRONT PANEL The LASERn MODE MDP command selects constant optical power mode MDP for the selected module s laser current source Ope oo Parameters None Notes On the front panel photodetector power mode is referred to as P mode This mode of operation uses the monitor photodiode feedback to maintain constant laser optical power The actual set point will be a monitor photodiode current value calculated with the CALPD conversion factor Therefore in this mode the set point is only as accurate as the user s CALPD value Examples LASER1 MODE MDP action sets the selected module s Laser1 operating mode to constant optical power mode 09 07 LDC 3916330 Series 63 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn MODulation C DEVICE DEPENDENT FRONT PANEL The LASERn MODulation command turns the selected module s laser modulation switch on or off white nrf space gt value gt Parameters nrf value 1 on enabled 0 off disabled Notes When the modulation switch is enabled for a ch
87. s LASERn monitor photodiode current setpoint is 30 uA for use in constant MDI mode Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn SET MDP C DEVICE DEPENDENT FRONT PANEL The LASERn SET MDP query returns the selected module s monitor PD power set point value Ope o 9o Parameters None The response is an nrf value which represents the constant power set point in mW Notes This set point is used in constant MDP P mode only Examples LASER1 Set MDP response 10 0 means the selected module s laser monitor PD feedback set point is 10 0 mW LASERn STEP DEVICE DEPENDENT The LASERn STEP command specifies the amount the selected module s laser constant current setpoint will change when the LASERn Inc or Lasern Dec command is issued white nrf space value Parameters nrf value representing the step amount in mA in the range 0 1 to 100 0 Notes The step applies to the constant current ILBW or IHBW mode setpoint Examples LASER1 STEP 10 action sets the selected module s Laser1 step size to 10 0 mA Laser1 ldi 20 Laser1 Step 10 0 Laser1 Inc 2 50 action sets the selected module s Laser1 setpoint to 20 mA sets the step size to 10 mA and performs two increments separated by 50 mSec After the increments the setpoint is 40 mA 09 07 LDC 3916330 Series 67 4 COMMAND REFERENCE LDC 3916330 Series Device Dependent C
88. s modules provide status registers which are summarized in the LDC 3916 mainframe These summaries are accessed by the ALLCOND and ALLEVE remote queries Refer to the LDC 3916 Instruction Manual for details on remote status reporting Each channel of the LDC 3916 may contribute to the ALLCOND and registers For the LDC 3916330 Series modules the enabled conditions of both the LAS and TEC functions are logically ORed and the summary is passed to the appropriate bit of the ALLCOND register see Figure 3 2 Likewise the enabled events of both the LAS and TEC functions are logically ORed and the summary is passed to the appropriate bit of the ALLEVE register see Figure 3 3 For example you may wish to have the LDC 3916 create an interrupt to the host PC in the event of the TEC output shutting off To do this you would first enable the event with the TEC ENAB EVE 1024 command This would allow the event to be passed to the ALLEVE register on the 3916 mainframe The ALLEVE status can be read by the ALLEVE query and the summary be monitored with the STB query To generate the SRQ interrupt for our example you must also set the Service Request Enable Register e g SRE 1 to allow the ALLEVE summary to generate the interrupt See the LDC 3916 Instruction Manual Chapter 3 for details on status structures Note When the laser voltage reaches the voltage limit setting LAS LIM V the hardware will always sh
89. s with the Photodiode Anode input to the module and directly measures the photodiode current 3 Enter the LDI calibration mode by pushing the DISPLAY MAIN front panel button then the SYS CONFIG soft key then the CAL soft key For the 3916332 or 3916334 modules press Cal LAS1 or Cal LAS2 to choose which source to calibrate on the dual current source modules or Cal LAS for the 3916338 module single current source module Then press the IPD Cal soft key the module s IPD calibration screen will appear 4 Press the Start soft key The internal calibration procedure will turn on the output and drive the LD current to approximately 15 of full range Allow the current to settle for at least 10 seconds 5 Use the ammeter and measure the actual photodiode current enter that value in uA into the highlighted IPDReal adjust field on the screen and press ADJUST ENTER Do not enter more than seven characters including the decimal point 6 The internal calibration procedure will then drive the LD current to approximately 65 of full range Allow the current to settle for at least 10 seconds 7 Measure the actual photodiode current enter that value in uA into the highlighted PDReal adjust field on the screen and press ADJUST ENTER After you have entered the second value the internal cal procedure calibrates the IPD current measurement circuit and displays a Completed message on the screen 09_07 LDC 3916330 Series 79
90. solution 0 01 mA 0 01 mA 0 01 mA Output Current Accuracy 25 C 0 05 of Full Scale 0 05 of Full Scale 0 07 of Full Scale Photodiode Current Range 0 to 5 000 pA 0 to 5 000 uA 0 to 5 000 pA PD Current Resolution 0 1 pA 0 1 pA 0 1 WA PD Current Accuracy 25 C 2 2 2 PD Responsivity Range 0 00 to 1000 00 uA mW 0 00 to 1000 00 mW 0 00 to 1000 00 mW PD Responsivity Resolution 0 01 uA mW 0 01 uA mW 0 01 uA mW Optical Power Range 0 00 to 500 00 mW 0 00 to 500 00 mW 0 00 to 5000 00 mW Optical Power Resolution 100 uW 100 uW 100 uW Forward Voltage Range 0 00 to 6 0 V 0 00 to 6 0 V 0 00 to 7 5 V Forward Voltage Resolution 1 1 10 mV 1 mV GPIB Forward Voltage Accuracy 13 2 mV 2 mV 7 mV 2 mV GPIB LDC 3916330 Series Lightwave INTRODUCTION AND SPECIFICATIONS Specifications CURRENT SOURCE NOTES D 7 8 9 10 11 12 13 values relate to a one hour warm up period Accuracy is 0 1596 above 2 5 Amps after 1 hour warm up period Over any 1 hour period half scale output Over any 24 hour period half scale output Measured optically evaluating noise intensity of a laser diode into a photodetector with 150 kHz Bandwidth Maximum output current transient resulting from normal operational situations e g power on off current on off as well as accidental situations e g power line plug removal Maximum output current tra
91. sters are configured in a manner which is similar to the status reporting registers However their values are not reported in the Status Byte Register These registers are used by the firmware to control the output enable for that function LASER or TEC The events and conditions which may be set to cause the TEC and LASER outputs to be turned off are shown in Figures 3 4 and 3 5 The default settings for these registers for an LDC 3916330 Series module are shown in Table 3 2 The registers take on these values at power up as the result of a RST command or when you choose Default from the Save Recall menu These settings are not affected by the PSC Power On Status Clear command Table 3 2 LDC 3916330 Series Default Settings for Output Off Registers t S ect mi ee P2 LASER Output Off Register Name Current Limit Voltage Limit N A Power Limit N A N A N A N A see Note 1 below N A Out of Tolerance TEC Output Off TEC High Temp Limit N A N A N A N A State Disabled Disabled Enabled Disabled Disabled Enabled w o 00 10 amp _ L o UN TEC Output Off Register Name Current Limit Voltage Limit High Temperature Limit Sensor Open TE Module Open Circuit Sensor Type changed Out of Tolerance Sensor Shorted
92. system was configured at the factory with your desired modules skip this section A CAUTION Static discharge can damage your new Laser Diode Controller Module Be certain you use proper grounding procedures before you unpack and install your controller module s into the mainframe Inspect the module for any visible shipping damage that may have occurred before inserting the module into the mainframe Pay special attention to the copper shielding material on the back edge of the module Be sure that the mainframe power is off before inserting your new laser diode controller module Damage from hot swapping is not included under the warranty Unwrap the module from the anti static bag it was packaged in 2 7 LDC 3916330 Series Lightwave INTRODUCTION AND SPECIFICATIONS Installing the LDC 3916330 Series Laser Diode Controller Module L Insert the module into the desired slot from the rear of the mainframe Each module is supported by two plastic card guides inside of the mainframe Insert the module 40 pin connector first by lining up the edges of the module frame with the appropriate card guides one on top and one on the bottom Carefully slide the module into the mainframe slot until the connector is seated Push firmly to fully seat the module until the rear panel of the module is flush with the mainframe Fasten the module to the mainframe with two screws located at the top and bottom of the module rear panel Genera
93. t and optical power of the laser diode A method to calculate the responsivity is suggested below 1 Measure with a calibrated detector the output power of the laser 2 Measure the corresponding monitor photodiode current 3 Calculate the responsivity CalPD by dividing the photodiode current by the optical power noting the units required are A mW Entering the Laser Channel Setup Menu DISPLAY ooor on To enter the setup menu push the CHAN key which displays the channel menu Select the correct channel number at the top of the display by pushing the ADJUST UP DOWN ARROW keys or turning the ADJUST knob For the 3916332 334 modules push the DISPLAY LAS soft key F2 to enter page 1 of the laser setup menu See image above 09_07 LDC 3916330 Series 17 OPERATIONS Operating a Laser in Constant Power P Mode For the 3916338 module push the display down arrow soft key F4 to enter page 1 of the laser setup menu See image above Selecting the Mode of Control DISPLAY Select the Mode parameter by pushing the DISPLAY UP DOWN ARROW keys until the Mode parameter is highlighted Repeatedly pushing the ADJUST UP DOWN ARROW keys or turning the ADJUST knob will cycle through the Constant Current low bandwidth Constant Optical Power P Constant Current high bandwidth Inbw and Photodiode Current Ipd control modes Set the LDC 3916330 Series Controller Module in Constant Optical Power mode
94. the condition status however is constantly changing Examples LASER1 EVE response 131 means that an open circuit changed state event 128 a voltage limit changed state event 2 and a current limit changed state event 1 have occurred since the last LASER1 EVEnt query 09 07 LDC 3916330 Series 53 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn INC DEVICE DEPENDENT The LASERn INC command increments he selected module s laser constant current set point by one or more steps A second parameter allows the time in milliseconds between increments to be set white nrf nrf space value value Parameters Two nrf values are required The first represents the number of steps and the second is the time in milliseconds between steps Notes The step size can be set using the LASERn STEP command Its default value is 1 0 mA The first parameter number of steps must be an integer between 1 and 50000 The minimum time to complete one increment is about 10 to 20 msec Therefore values for the second parameter time between increments have a practical minimum of 20 The maximum number of msec is 65535 Examples LASER1 STEP 0 5 LASER1 INC 10 50 action the step size is set to 0 5 mA and the set point is incremented by 0 5 mA ten times each increment being separated by 50 msec LASERn LDI DEVICE DEPENDENT FRONT PANEL The LASERn LDI command sets the selected mo
95. the screen and press ADJUST ENTER Do not enter more than seven characters including the decimal point 6 The internal calibration procedure will then drive the LD current to approximately 75 of full range Allow the current to settle for at least 10 seconds 7 Measure the actual voltage across the load resistor enter that value in Volts into the highlighted VReal adjust field on the screen and press ADJUST ENTER After you have entered the second value the internal cal procedure calibrates the laser forward voltage measurement circuit and displays a Completed message on the screen Be sure to calibrate both sources LAS1 and LAS2 for each module This ends the section on front panel local calibration of your current source The next section discusses calibration through the IEEE488 2 GPIB interface LDC 3916330 Series Lightwave TROUBLESHOOTING Remote Calibration of the LDC 3916330 Dual Current Source Module Remote Calibration of the LDC 3916330 Dual Current Source Module The 3916330 Controller Modules can be calibrated remotely via the GPIB Interface All of the required calibration commands are listed in Table 4 1 in Chapter 4 The procedures below are general guidelines for writing a program to calibrate your instrument Laser Current Source Calibration There are three calibration adjustments for each current source of the 3916330 Series Module They are calibration of the constant current LDI s
96. the selected module s laser output on or off white nrf space gt value gt Parameters nrf value 1 on 0 off Notes After the selected module s laser output is turned on it may be useful to wait until the output is fully on before performing further operations but it is not necessary When the output is turned on there is a two second delay before the output is actually enabled This delay is a safety requirement When a current source output is off an internal short is placed across the output terminals Examples LASER1 LDI 20 Laser1 out on action sets the selected module s Laser1 output current to 20 mA and then turns the selected module s Laser1 output on Laser1 Out 0 action turns off the selected module s Laser1 current source LASERn OUTput OMMON DEVICE DEPENDENT FRONT PANEL The LASERn OUTput query returns the status of the selected module s laser output switch Parameters None The response is nrf values Notes Although the status of the switch is on the output may not have reached the set point value Examples Laser1 OUT response 0 means that the selected module s Laser1 output switch is disabled devices may be safely disconnected or connected at the selected module s Laser1 output terminal LASER1 OUT response 1 means that the selected module s Laser1 output switch is enabled 09 07 LDC 3916330 Series 65 66 COMMAND REFERENCE
97. tion mode by sending the following command over GPIB LASERn CAL LDI 4 The internal cal procedure will begin by setting the Laser output current to approximately 25 of its full range Allow the current to settle for at least 10 seconds If this calibration value is to be measured and entered remotely via a GPIB controlled DMM for example the actual value of the current should not be entered until the LDC 3916 controller is ready to receive it 09_07 LDC 3916330 Series 81 82 TROUBLESHOOTING V Remote Calibration of the LDC 3916330 Dual Current Source Module 5 Check to see if the internal cal procedure is ready for the measurement Send the following query to the module LASERn CAL STATUS The cal procedure is ready for a measurement if it returns the value 1 Query the status until the value that is returned is 1 6 Enter the measured current in mA by sending the following command LASERn CAL MEAS current in mA e g LASER1 CAL MEAS 267 878 Note The internal cal procedure will store this value and briefly change its measurement status to 0 to indicate that it is not yet ready for another measurement This will occur after each time a new measurement is entered 7 Thecal procedure will set the output current to approximately 75 of its output range Allow the current to settle for at least 10 seconds 8 Check to see if the internal cal procedure is ready for the measurement Send the following query to the
98. ue whose sum represents the enabled bits 1 Current Limit 256 N A 2 Voltage Limit 512 Output Out of Tolerance 4 N A 1024 N A 8 Power Limit 2048 N A 16 N A 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 N A 32768 N A Notes This register is read using the LASERn ENABle OUTOFF query The factory default value for this register is 8 only power limit will shut off the output Enabling voltage limit will cause the output to shut off when the laser diode voltage reaches a level that is about 0 25 volts below the VLim setpoint Regardless of how this register is set the current source will shut off when the laser diode voltage exceeds the VLim setpoint this is an open circuit error Examples LASER1 ENAB OUTOFF 9 action sets the selected module s LASER1 output off enable register so that either a power limit or a current limit condition will cause the LASER1 output to be turned off NOTE Open circuit or interlock open conditions will always turn off the current source They are not included in the output off enable register because they cannot be disabled 09 07 LDC 3916330Series 51 COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn ENAB1e OUTOFF COMMC DEVICE DEPENDENT FRONT PANE The LASERn ENABle OUTOFF query returns the contents of the selected module s laser output off enable register OP Parameters None The response is the sum of the follo
99. ut the laser off The Laser Voltage Limit referred to in the Event Condition and Output Off Registers occurs when the voltage is about 0 25 volts less than the voltage limit setting This feature can be used for a warning before the actual voltage limit is reached 28 LDC 3916330 Series Lightwave 09 07 REMOTE OPERATIONS Status Reporting LASER1 Condition Status Register LASER1 COND 5 pap pone JE dl 5 JE 0 E fuss TOM Eu ice shpe JE ve 5 js 0 LASER1 Condition Status Enable Register LASER1 ENABle COND lt nrf gt LASER 1 ENABle COND To ALLCOND LOGICAL OR Register LASER2 Condition Status R egister LASER2 COND OSS EEEE 06 is papam pamope pe 2 e 4 3 2 119 LASER2 Condition Status Enable Register LASER2 ENABIe COND gt LASER2 ENABle COND LASER1 Condition Bit Reference LASER 2 Condition Bit Reference 0 Current Limit 8 Output Shorted 0 Current Limit 8 Output Shorted 1 Voltage Limit 9 In Tolerance 1 Voltage Limit 9 In Tolerance 2 n a 10 Output On 2 n a 10 Output On 3 Power Limit 11 n a 3 Power Limit 11 n a 4 Interlock Error 12 n a 4 Interlock Error 12 n a 5 13 n a 5 13 n a 6 n a 14 n a 6 14 n a 7 Open Circuit 15 n a 7 Open Circuit 15 Figure 3 2 LDC 3916330 Series Condition Registers LDC 391
100. wing 1 Current Limit 256 N A 2 Voltage Limit 512 Output Out of Tolerance 4 1024 N A 8 Power Limit 2048 N A 16 N A 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 N A 32768 N A Notes The register can be set by using the LASERn ENABle OUTOFF command The selected module s laser output status can be monitored by the LASERn EVEnt query Examples LASER1 ENAB OUTOFF response 8 means that the selected module s power limit condition will cause the selected module s Laser1 output to be turned off 52 7 LDC 3916330 Series uix Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn EVEnt DEVICE DEPENDENT FRONT PANE The LASERn EVEnt query returns the contents of the selected module s laser event status register Parameters The response is the sum of the following 1 Current Limit Changed State 256 Output Shorted Changed State 2 Voltage Limit Changed State 512 Output Changed Tolerance State 4 N A 1024 Output On Changed State 8 Power Limit Changed State 2048 N A 16 Interlock Changed State 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit Changed State 32768 N A Notes The events in this register will not be reported to the 3916 s status byte unless they are selected using the LASERn ENABle EVEnt command The event status register is only cleared when it is read or by the CLS command
101. wing two conditions will be reported in summarized form to the 3916 s status byte output shorted 256 and voltage limit 2 Note that the output shorted condition is the same as output off 48 LDC 3916330 Series uix Lightwave COMMAND REFERENCE LDC 3916330 Series Device Dependent Command Reference LASERn ENAB1le EVEnt COMMON DEVICE DEPENDENT The LASERn ENABle EVEnt command sets the selected module s laser event status enable register The bits in this register determine which bits in the laser event status register are summarized in the 3916 status byte vor roo EHE Parameters nrf value whose sum represents the bits which are enabled 1 Current Limit Changed State 256 Output Shorted Changed State 2 Voltage Limit Changed State 512 Output Changed Tolerance State 4 N A 1024 Output On Changed State 8 Power Limit Changed State 2048 N A 16 Interlock Changed State 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit Changed State 32768 N A Notes The register is read with the LASERn ENABle EVEnt query The selected module s laser event status can be monitored by the LASERn EVEnt query See the Status Reporting section of the 3916 manual for more information regarding condition reporting Examples LASER1 ENAB EVENT 136 action only the open circuit changed state 128 and power limit changed state 8 events will be reported in summarized form to the 39165 status byte

Installing the LDC-3916330 Series Laser Diode Controller Module

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