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LDC-3900 Front Panel - Newport Corporation

1. 50 00 40 00 30 00 20 00 10k 25 k 100k 10 00 0 00 60 40 20 0 20 40 60 80 100 120 140 160 TEMPERATURE DEGREES C Figure A 1 Thermistor Resistance vs Temperature Once the constants A and B are determined the LDC 3900 Laser Diode Controller is programmed with the following values of C1 and C2 C1 A 10 8 G2 B8 10 Computer Program We have included a computer program called STEIN1 that uses a least squares curve fitting routine to determine the values of C1 and C2 The program is written in IBM s advanced BASICA You must create a data file for your thermistor that describes the resistance at various temperatures The temperature verses resistance calibration data can be obtained from the thermistor manufacturer Enter the resistance at various temperatures as data points into an ASCII file You can write the data file on a word processor but you must use non document mode so special word processing characters are not inserted into the data file Format the data with one temperature resistance pair per line and at least one space separating the two numbers Temperatures should be in centigrade and resistances in ohms For an LDC 3900 Series 187 carrer A The Steinhart Hart Equation accurate determination of the coefficients we recommend that you use at least twenty data points uniformly spread over the intended range of use Enter a 1 to signify the end of the resistance data and
2. TEC MODE ITE action sets the TEC controller for constant TEC current operation for the selected TEC channel Tec Mode lte action sets the TEC controller for constant TEC current operation for the selected TEC channel TEC MODE R COMMON Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT FRONT PANEL The TEC MODE R command selects TEC constant thermistor resistance linear sensor reference mode for the selected TEC channel None Since sensor resistance or linear sensor reference is a function of temperature this mode also controls the TEC output load temperature but it bypasses the use of the conversion constants for set point calculation This allows finer control of temperature in cases where the sensor s temperature model and therefore the constants is not known Changing modes causes the selected TEC s output to be forced off and the new mode s set point value will be displayed In local operation the TEC control mode is set by pressing the TEC MODE SELECT switch until the desired mode is indicated by corresponding LED lit ON TEC MODE R action sets the TEC controller for constant thermistor resistance linear sensor reference operating mode for the selected TEC channel Tec Mode R action sets the TEC controller for constant thermistor resistance linear sensor reference operating mode for the selected TEC channel MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands
3. 0 00 cece eee eee 5 Tilt Foot Adjustment o oooccccocc 6 Rack MOUNDO ici outa e ee ob i ald ee eee de ea eee 6 Im IL Lightwave LDC 3900 Series E i Power Up Sequence 0 00 c cece ete eens 6 LDC 3900 Front Panel 00 0 0000 a 9 Front Panel a eee eae ee 9 General FunctionS arora asni 000 0c cece eee ees 10 TEC Functions 0 00 000 ccc eee 12 Conditions Which Will Automatically Shut Off a TEC Output 14 Laser Functions 0 0 0 0 0000 cc ccc eee ees 14 Automatic Laser Shutoff Conditions oooooooo 16 GPIB Section viii aed ale Bod de lew adie wee wide Bee dae eds 16 Adjust S CHON viso rascar beet ee ch eRe eed Beddoes 17 Automatic Set Point Adjustment 0 0 00 cece eee 17 Output Section sears weed ewe teedae Ved aden es E eee eke s 18 TEC Mode Section 0 00 000 ccc eee ee 18 TEC Mode Select 2 000000 000 eee 19 TEC Mode Indicators 0 0 0 0 0000 ccc ee 19 TEC Display Switch Section 0 0 00 ccc ees 19 TEC Display S6 ira ra a wed Ya ewe ee ad ea 20 TEC Display Indicators and Switches 000 cence eee 20 TEC Parameter Section 0 0 0 0 0c ccc ee 21 TEC Parameter Select 0 00000000 ccc ee 21 TECG Parameter Set unos a Geared y dei aah Ga dade 22 LIMITE ta ad 22 LIMITA liceo it e aed 22 CONSI A A ed te tet 23 A ete ated oie ke eae es eh See ES Sete 23 TEC Channel Indicators 0 000 000 ce
4. 420 CMDS Tec Tol 0 5 0 5 GOSUB 1000 Set the toleranc to 0 5xC for 0 5 seconds 430 CMDS Tec Gain 100 GOSUB 1000 Set control loop gain 440 CMDS Tec Step 100 Tec Mode T GOSUB 1000 Temperature mode with 10xC step 450 CMDS Tec T 30 Output ON GOSUB 1000 Start laser temperature at 30xC 460 CMDS Las Tol 1 0 4 GOSUB 1000 470 CMDS LAS LIM I 100 GOSUB 1000 Set output current limit to 100 mA 480 CMDS Las Step 0 5 Las Output ON GOSUB 1000 Turn LASER output on and set 0 5 mA step 490 500 TAKE DATA 520 FOR X 1 TO 3 Gather data over 3 temperatures 530 d 540 CMDS Las LDI 0 WAI GOSUB 1000 Reset output to O mA wait for temperature 550 and current to reach tolerance levels 560 FOR Y 1 TO 100 Step drive current from 0 to 50 mA 570 j 178 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Programming Examples 580 CMD Las Inc WAI GOSUB 1000 Wait until drive current is within tolerance 590 CMDS Las MDI GOSUB 1000 Take the monitor photodiode current measurement 600 INPUT 2 LS Input the value 610 CMD Las LDI GOSUB 1000 Take the drive current measurement 620 INPUT 2 IS Input the value 630 CMDS Tec T GOSUB 1000 Take the temperature measurement 640 INPUT 2 TS Input the value 650 700 j PRINT OUT RESULTS T10
5. 0 eee eee 74 Common Commands coco 75 LDC 3900 Device Dependent Commands 0000055 75 Command Paths ws eeens das de bers dead bees dee ares a 83 LDC 3900 Device Command Reference 0000e eee eeee 85 Error Messages ooooocooocrr ee ete 174 LDC 3900 Programming Examples anunua naaa 175 TEC Step and Delay Example Program ocoocccccccccooo o 175 iv LDC 3900 Series ML Lightwave Laser Constant Power Mode Example Program 175 L l vs Temperature Example Program 0 0 00 eae 176 Chapter5 Error Messages Appendix A Steinhart Hart Equation The Steinhart Hart Equation 0 0000 eee 185 Computer Program 0000 ete 187 Appendix B AD590 and LM335 Sensor Calibration INtFOdUCHION eet ick eee rr ais 191 AD590 SENSOM 2x6 fc be Garena ler deeded es 191 LM335 SCNSOP iaa ad N 193 One Point Calibration Method 000200 cee eee ee 194 Two Point Calibration Method 0 000 e eee eee 194 INdOX ici es fe dae 2 Hila b Phe ee ek Sle daw ele PRS Index i 04_10 LDC 3900 Series v vi LDC 3900 Series ML Lightwave MmiLxX Lightwave Figure 2 1 Figure 2 2 Figure 2 3 Figure 2 4 Figure 2 5 Figure 2 6 Figure 2 7 Figure 2 8 Figure 2 9 Figure 2 10 Figure 2 11 Figure 2 12 Figure 2 13 Figure 2 14 Figure 2 15 Figure 2 16 Figure 2 17 Figure 2 18 Figure 2 19 Figure 2 20 Figure 2 21 Figure 2 22 Figure 2
6. 720 T VAL TS I VAL IS L VAL LS Convert data types 720 IMAGES Hitt HEH HH Hit tH 730 PRINT USING IMAGES T 1I L 740 750 NEXT Y 760 770 CMDS Tec Inc GOSUB 1000 Increment the temperature 780 790 NEXT X 820 04_10 LDC 3900 Series 179 COMMAND REFERENCE LDC 3900 Programming Examples 830 CMDS Las Output OFF Tec Output OFF Turn off outputs 840 END 850 1000 OUTPUT SUBROUTINE 1010 1020 PRINT 1 OUTS ADS CMDS RETURN Output the command and return 180 LDC 3900 Series MIL Lightwave CHAPTER 5 ERROR MESSAGES 5 B E a t8 a a El E El a E E a E E Error messages may appear on the TEC or Laser displays when error conditions occur in the respective functions of the LDC 3900 Modular Laser Diode Controller For example a current limit error in the TEC side of the LDC 3900 will be displayed on the TEC display In most cases the error message will appear for three seconds and then the display will revert to its former state In the case of multiple error messages the LDC 3900 will show each message for up to three seconds each In remote operation the current error list can be read by issuing the ERR query When this is done a string will be returned containing all of the error messages which are currently in the error message queue Table 5 2 on page 182 contains all of the error messages which may be generated by the LDC 3900 M
7. NUMBER OF NAME PARAMETERS EXPECTED FUNCTION LAS STEP NONE Returns the present channel s LAS step value LAS TOL 2 Used to set the present channel s LAS set point tolerance value and time period value for validation i e used to determine if a set point has been reached must be within tolerance for the time period LAS TOL NONE Used to return the present channel s LAS set point tolerance value and time period value for validation i e used to determine if a set point has been reached must be within tolerance for the time period MES 1 Used to enter a string message of up to 16 bits MES NONE Returns a previously stored ASCII message RAD 1 Used to set the radix type for numerical data Decimal binary octal and hexadecimal are allowed RAD NONE Used to return the radix type for numerical data Decimal binary octal and hexadecimal are allowed SECURE 1 To be used by authorized service personnel only to gain access to protected data TEC ALL CONST 3 Used to enter the Steinhart Hart constants for R T conversion one set is used for all TEC channels Also used to enter constants for AD590 LM335 and RTD TEC ALL CONST NONE Used to read back all the channels Steinhart Hart constants for R T conversion Also used to read back constants for AD590 LM335 and RTD TEC ALL GAIN 4 Used to set all the channels TEC control loop gain parameters TEC ALL GAIN NONE Used to return all the channels TEC control loop gain para
8. TEC STB response 0 means the selected TEC channel s condition and event registers did not cause summary bits 1 or O of the Status Byte Register to be set LDC 3900 Series 167 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC STEP Parameters Notes Examples DEVICE DEPENDENT The TEC STEP command is used to increment or decrement the selected TEC control mode set point by the given amount when used with the TEC INC or TEC DEC command An integer value of the step amount in the range 1 9999 The step of 1 corresponds to the smallest incremental change of the mode For example a step of 1 means 0 1 C 1 W THERM 0 01 mA AD590 0 1 mV LM335 0 01 W RTD or 1 mA ITE mode TEC Mode t TEC t 20 TEC Step 10 TEC Inc TEC Set t sets the selected TEC s step to 1 C so the TEC Set t query will return a value of 21 mA Tec Step 100 sets the selected TEC s step size to 100 could mean 10 0 C 100 W THERM 1 mA AD590 10 mV LM335 1 00 W RTD or 100 mA ITE mode TEC STEP Parameters Notes Examples DEVICE DEPENDENT The TEC STEP query is used to read back the TEC STEP value for the selected TEC channel This value is used to increment or decrement the selected TEC control mode set point by the given amount when used with the TEC INC or TEC DEC command None The response is an lt nrf value gt The step of 1 corresponds to the smallest incremental change of the mode
9. Ta V Then C1 and C2 can be determined by the following Cin U V C1 C2 V C2 6 Replace C1 with C1 by selecting the C1 parameter and entering the new C1 value Replace C2 with C2 by selecting the C2 parameter and entering the new C2 value 04_10 LDC 3900 Series 195 onarte BD Two Point Calibration Method 196 LDC 3900 Series MIX Lightwave
10. 157 158 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC GAIN COMMON DEVICE DEPENDENT FRONT PANEL The TEC GAIN query returns the value of the control loop gain for the selected TEC channel Parameters None The response value is one of the following values 1 0 3 0 10 0 30 0 100 0 or 300 0 Notes If a value between 1 and 300 other than 1 3 10 30 100 or 300 is entered via the GAIN command the nearest valid value will be stored If an entered value is greater than 300 an error E222 will be generated and the GAIN parameter will not be changed If an entered value is less than 1 an error E223 will be generated and the GAIN parameter will not be changed In local operation the gain value is queried by selecting the GAIN parameter and visually reading the display Examples TEC Gain response 30 0 means the control loop gain for the selected TEC channel is set to 30 Tec GAIN response 100 0 means the control loop gain for the selected TEC channel is set to 100 TEC INC DEVICE DEPENDENT The TEC INC command increments the selected control mode set point by one step for the selected TEC channel Parameters None Notes The incremental amount is one step The step size can be edited via the STEP command its default value is 0 1 C 1 mA ITE 1 W THERM 0 01 mA AD590 0 1 mV LM335 or 0 01 W RTD depending on the mode of operation Examples TEC MODE T TEC STEP 2 TEC I
11. Tec Mode R TOLer 2 2 5 action the selected TEC channel s TEC controller will be in tolerance when the thermistor resistance assuming the sensor is a thermistor is within 20 ohms of the set point value for a period of 2 500 seconds 170 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC TOLerance COMM DEVICE DEPENDENT The TEC TOLerance query allows the programmer to determine how the selected TEC s temperature tolerance is set Parameters None The response consists of two data units the first represents the set point tolerance and the second represents the time window in seconds Refer to the description of these parameters in the TEC TOL command Notes The TEC tolerance specification is used in the TEC status event and condition registers and so entering or exiting TEC tolerance may be tested by polling via the TEC COND query or used to generate service requests Examples Tec Tol response 0 2 5 means the selected TEC channel has a TEC tolerance setting of 0 2 C when in T mode with a time window of 5 000 seconds TEC TOL response 1 0 20 means the selected TEC channel has a TEC tolerance setting of 1 0 C when in T mode or 10 ohms when in R mode using a thermistor sensor with a time window of 20 000 seconds TEC V COMMON DEVICE DEPENDENT The TEC V command sets the TEC s voltage value during calibration of the selected TEC channel 39034 only P
12. 1 step equals 0 1 C 1 mA ITE 1 Q Therm 0 1 mV LM335 0 01 uA AD590 or 0 01 Q RTD Range is 1 9999 steps TEC STEP NONE Returns the value of the present channel s TEC step TEC T 1 Used to set the present channel s TEC constant T temperature set point TEC T NONE Returns the present channel s TEC measured temperature value measured about every 600 msec TEC TOL 2 Used to set the present channel s TEC set point tolerance value and time period value for validation i e used to determine if a set point has been reached must be within tolerance for the time period TEC TOL NONE Used to return the present channel s TEC set point tolerance value and time period value for validation i e used to determine if a set point has been reached must be within tolerance for the time period TEC V 1 Used for calibration of TEC voltage measurement 39034 only TEC V NONE Returns the TEC voltage measurement 39034 only TERM 1 Sets the program message terminator TERM NONE Returns the value of the program message terminator 82 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION TIME NONE Returns the elapsed time since the LDC 3900 Modular Laser Diode Controller was last powered up TIMER NONE Returns the elapsed time since the timer was last reset C
13. Examples las set mdi response 30 0 means the selected channel s laser monitor PD current is set point is 30 mA for use in constant P mode with CALPD 0 LAS Set MDI response 100 0 means the selected channel s laser monitor PD current is set point is 100 mA for use in constant P mode with CALMD 0 124 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer SET MDP COMM DEVICE DEPENDENT FRONT PANEL The LASer SET MDP query returns the selected channel s laser monitor PD power set point value when CALMD CAL PD is not zero in mW Parameters None The response is an lt nrf value gt which represents the selected channel s constant PPD set point in mW Notes This set point is used in constant MDP mode only In local operation the constant PPD set point is read by selecting P mode when CAL PD gt 0 then pressing the LASER DISPLAY SET switch and then visually reading the LASER display Examples LAS Set MDP response 10 0 means the selected channel s laser monitor PD feedback set point is 10 0 mW CALPD gt 0 Laser Set MDP response 25 0 means the selected channel s laser monitor PD feedback set point is 25 0 mW CALPD gt 0 LASer STB Comm DEVICE DEPENDENT The LASer STB query is used to read back the selected LAS channel s status summaries for conditions and events This value is used to determine which LAS channel s have conditions and or events wh
14. If an error occurs on a TEC or Laser channel which is not presently selected the corresponding Channel Indicator will blink In most cases the error message will appear for three seconds and then the display will revert to its former state In the case of multiple error messages the LDC 3900 will display the highest priority message whenever possible However all error messages even those not displayed on the front panel will be available via the ERR query In remote operation the present error list can be read by issuing the ERR query When this is done a string will be returned containing the previously unread error messages up to 10 which are currently in the error message queue Chapter 5 Error Messages contains an explanation of the error messages that are reported by the LDC 3900 on the display or via remote operation 174 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Programming Examples LDC 3900 Programming Examples This section is intended as a simple example of programming the LDC 3900 over the GPIB The first short examples contain sections of a BASIC program These examples are not complete programs and therefore cannot be used by themselves However they illustrate the simplicity of programming the LDC 3900 and show some possible uses of its features but the initialization of variable and files has been omitted for simplicity The last example contains a complete BASIC program whic
15. LDC 3900 Series im IL Lightwave COMMAND REFERENCE TITER 4 LDC 3900 Device Dependent Commands CHARTER Ts Table 4 2 on page 75 lists all of the LDC 3900 s device dependent commands with the full path shown for each command and a brief explanation of its usage For more information see LDC 3900 Device Dependent Commands on page 75 LDC 3900 Device Dependent Commands on page 75 presents a more detailed look at the LDC 3900 device dependent commands including syntax diagrams and example usage Common Commands Another type of command is the common command These commands are common to instruments which support the ANSI IEEE 488 2 standard and are not necessarily reflected by front panel operations Some of the common commands are useful for advanced programming techniques such as generating service requests However common commands are not necessary for remote operation and the beginning programmer may chose to ignore them entirely The common commands for the LDC 3900 are documented in Chapter 3 Two common commands which are reflected by front panel operations are SAV and RCL These commands remotely perform the same operations as when the Save and Recall parameters are changed during Local front panel operation LDC 3900 Device Dependent Commands This section contains all of the device dependent commands for the LDC 3900 Modular Laser Diode Controller listed in alphabetical order Sub sections for each path are pr
16. Notes This command is useful with combination modules when the LAS and TEC outputs need to be controlled separately For combination modules this command effects only the LAS output With combination modules when only the TEC or LAS output is on the corresponding output LED will blink After a channel s output is turned on it may be useful to wait until the output is stable within tolerance before performing further operations but it is not necessary When the LASER output is off it is safe to connect or disconnect devices to the LASER output terminals When aLASER output is off an internal short is placed across the output terminals If this occurs for the selected LAS channel it causes the OUTPUT SHORTED light to come on Examples Las Only Out 1 action turns ON the laser output for the selected LAS channel TEC output on the selected channel is not effected LAS only OUT 0 action turns OFF the laser output for the selected LAS channel The TEC output on the selected channel is not effected LASer OUTput COMMON DEVICE DEPENDENT FRONT PANEL The LASer OUTput command turns the selected channel s laser output on or off Parameters An lt nrf value gt 1 on O off Notes After the selected channel s output is turned on it may be useful to wait until the output is stable within tolerance before performing further operations but it is not necessary When the LASER output is off it is safe to connect or disconnect devices to
17. T R be SET ar 1P0 P Po pmm LASER ENABLE mum LASER MODE MM poes OUTPUT TT PA TEC MODE TECE PARAMETER GIEEMDLASER OFF on LMI te um z Fi aw oT O UMT H ime o qn a a a o mai SELECT oN ON ON ON E CONST CALPD o Diw SELECT O GAIN O 1 mew SELECT O SAVE SET RECALL m TEC DISPLA LASER MODE UTPUT Externa iteh Sect Modulat TEC MODE PARAME TEI Figure 2 1 LDC 3900 Front Panel General Functions This section gives a brief synopsis of functions which effect both TEC and Laser controller operation The GPIB section is used when the optional remote GPIB operations are implemented For more information see GPIB Section on page 16 GPIB REMOTE TALK LISTEN Figure 2 2 GPIB Section MIL Lightwave 10 LDC 3900 Series 04 10 OPERATION LDC 3900 Front Panel The Laser Enable switch is used to enable disable the Laser output Note the interlock pins 1 and 2 of the Laser output connector must be shorted also see module manual for details LASER ENABLE Figure 2 3 Laser Enable Switch The Adjust section contains the Adjust Knob for entering values and it contains the Adjust LAS TEC switches for selecting the adjustment mode for each of the modules Available LAS and TEC channels are indicated by the corresponding TEC Cha
18. TEC MODE T COMMON DEVICE DEPENDENT FRONT PANEL The TEC MODE T command selects TEC constant temperature mode for the selected TEC channel Parameters None Notes Since TEC load temperature is derived from sensor resistance reference constant R and T modes are related In T mode the set point is converted to resistance or reference using the appropriate constants and conversion model Changing modes causes the selected TEC channel s output to be forced off and the new mode s set point value will be displayed In local operation the TEC control mode is set by pressing the TEC MODE SELECT switch until the desired mode is indicated by corresponding LED lit ON Examples TEC MODE T action sets the TEC controller for constant load temperature operating mode for the selected TEC channel tec mode T action sets the TEC controller for constant load temperature operating mode for the selected TEC channel TEC ONLY DEVICE DEPENDENT The TEC ONLY command path is used to get to the TEC only commands The following commands may be reached directly from the TEC ONLY command path TEC ONLY OUTput TEC ONLY OUTput DEVICE DEPENDENT The TEC ONLY OUTput command turns the TEC output only on or off for the selected channel Parameters An lt nrf value gt 1 non zero on O off Notes This command is useful with combination modules when the LAS and TEC outputs need to be controlled separately For combination
19. The response will be the sum of all of the enabled bits as represented in Figure 3 9 on page 50 The syntax for the ESE query is OA HOP ESR This query will cause the LDC 3900 to return the value of the Standard Event register This allows the user to determine which type of error has occurred for example The value of the response will be the sum of the bits as represented in Figure 3 9 on page 50 The syntax for the ESR query is OO A HOH This query will cause the LDC 3900 to return the following identification string IDN 04_10 LDC 3900 Series 51 3 REMOTE OPERATION 2 Common Commands and Queries ILX Lightwave 3900 8 digit serial number 3 digit software version number This identifies the specific device for the user The manufacturer model serial number and version number are listed in order The syntax for the IDN query is QOL HC OPC The OPC command causes the LDC 3900 to generate the operation complete message in the Standard Event Status Register when all pending overlapped commands have been completed The syntax for the OPC command is 950 i OPC This query places an ASCII character 1 into the LDC 3900 Modular Laser Diode Controller s Output Queue when all pending operations have been finished See also Operation Complete Definition on page 66 52 LDC 3900 Series MIL Lightwave 04 10 REMOTE OPERATION Common Commands and Queries i The syntax for t
20. and SET indicators in the LASER DISPLAY area of the front panel The status of the switch is on if its indicator is lit and the SET indicator is not lit Examples LAS DIS LDI response 0 means that the LASER DISPLAY switch is not currently active laser current is not displayed Las dis ldl response 1 means that the LASER DISPLAY switch is currently active laser current may be displayed for the present channel LASer DISplay LDV Go DEVICE DEPENDENT FRONT PANEL The LASer DISplay LDV command sets the laser display to show the constant current measurement for the present LAS channel Parameters None Notes The actual LASER V display is turned off automatically when another LASER DISPLAY selection is enabled In local operation the LASER V value is displayed by pressing the V switch in the LASER DISPLAY area of the front panel Examples LAS DIS LDV action enables the LASER display for voltage values Laser Dis LDV action enables the LASER display for voltage values LASer DISplay LDV COMM DEVICE DEPENDENT FRONT PANEL The LASer DISplay LDV query returns the status of the LASER DISPLAY V switch Parameters None The response will be either O off or 1 on Notes In local operation the status of the V switch is determined by visually inspecting the V and SET indicators in the LASER DISPLAY area of the front panel The status of the V switch is on if its indicator is lit and the SET indi
21. apply to that channel If an invalid LAS CHAN is selected an E533 error will be generated and the LAS channel will not be changed Examples las chan 1 Idi action selects channel 1 for LASER display and adjustment the response will be the measured laser diode current from channel 1 assuming channel 1 contains a LASER module Laser Chan 4 Laser Out On action selects channel 4 for LASER display and adjustment turns on the output of the LASER module in channel 4 if possible LAS CHAN COMMON DEVICE DEPENDENT FRONT PANEL The LASer CHAN query returns the channel number of the LASER module which has been selected for display and adjustment Parameters None The response will be the channel number of the selected LASER module Notes If no LASER channels exist the response will be 0 In local mode the user would read the LASER channel selection visually The selected channel would have the corresponding orange LAS LED lit in the ADJUST section Examples LAS CHAN response 1 means the LASER module in channel 1 is selected for adjustment and display Laser CHan response 2 means the LASER module in channel 2 is selected for adjustment and display 04 10 LDC 3900 Series 101 102 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer COND COMMON Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT RON The LASer COND query returns the value of the status conditio
22. commands are described in Chapter 4 Overview of the LDC 3900 Syntax Generally a command or query is entered spelled as shown in Table 4 1 on page 74 The command query MUST CONTAIN all of the letters which are shown in upper case in Table 4 1 on page 74 However the LDC 3900 Modular Laser Diode Controller s command parser is NOT CASE SENSITIVE so upper or lower case may be used in any combination The lower case letters shown with the commands in Table 4 2 on page 75 are optional letters and may be used for clarity For example the following commands are equal and only the first three letters DIS are required while the other letters play are optional LAS DISp1 LAS Display 1 and LAS DisP1 are equivalent The syntax of the LDC 3900 commands follows the rules laid out in the IEEE 488 2 standard Colons indicate the start of anew command path while semicolons indicate a separation of commands within a command string A leading semicolon on a command may be used to return the LDC 3900 command parser to the command path root 46 LDC 3900 Series im IL Lightwave 04 10 REMOTE OPERATION Getting Started with GPIB Spaces or white space see White Space on page 39 for a definition may be placed anywhere in a command string after the command header or query question mark and must be used to separate the command header from the first parameter or program data The following examples show valid syntax
23. depending on the modules installed in the LDC 3900 The default factory settings for these registers are shown in Table 3 2 on page 70 These settings are not effected by the PSC Power On Status Clear command Logical Enable Register Turn Output Off LASer ENABle OUTOFF lt nrf gt LASer ENABle OUTOFF Figure 3 12 An LDC 3900 LASER Module Output Off Register 68 LDC 3900 Series im IL Lightwave REMOTE OPERATION N Q CHAPTER 3 Status Reporting i Bit Reference 0 LASER Current Limit 8 N A 1 LASER Voltage Limit 9 LASER Output Changed to be out of Tolerance 2 TEC Output is Off Channel 1 10 TEC Output is Off Channel 4 Event Event 3 LASER Power Limit output on 11 TEC High Temperature Limit Channel 1 Condition 4 N A 12 Hardware Error 5 TEC Output is Off Channel 2 13 TEC High Temperature Limit Channel 2 Condition Event 6 TEC Output is Off Channel 3 14 TEC High Temperature Limit Channel 3 Condition Event 7 N A 15 TEC High Temperature Limit Channel 4 Condition TEC Output Off Register Logical TEC Output Off Enable Register Turn Output Off TEC ENABle OUTOFF lt nrf gt TEC ENABle OUTOFF Figure 3 13 An LDC 3900 TEC Module Output Off Register 04_10 LDC 3900 Series 69 REMOTE OPERATION _ Status Reporting Bit Reference 0 TEC Current Limit 8 Sensor Type Change while output on Event 1 TEC Voltag
24. response 1040 means that the Output on off state change and Interlock changed LASER events for the selected channel will be reported in summarized form to the status byte register bit 2 Radix Hex Las Enab Eve response HFF9B means that all of the above events will be reported in summarized form to the status byte register bit 2 for the selected channel 04 10 LDC 3900 Series 111 112 COMMAND REFERENCE LDC 3900 Device Dependent Commands LDC 3900 Series LASer ENABle OUTOFF Parameters Notes Examples DEVICE DEPENDENT The LASer ENABle OUTOFF command sets the status outoff enable register of the selected channel s LASER operations things which will turn the LASER output off An lt nrf value gt whose sum represents the enabled bits 1 LASER Current Limit 256 N A 2 LASER Voltage Limit 512 Output is Out of Tolerance 4 TEC Output is Off Channel 1 Event1024 TEC Output is Off Channel 4 Event 8 Power Limit With Output On 2048 TEC High Temp Limit Channel 1 Condition 16 N A 4096 Hardware Error 32 TEC Output is Off Channel 2 Event8192 TEC High Temp Limit Channel 2 Condition 64 TEC Output is Off Channel 3 Event16384 TEC High Temp Limit Channel 3 Condition 128 N A 32768 TEC High Temp Limit Channel 4 Condition The enabled LASER outoff bits for the selected channel can be read by using the LASer ENABle OUTOFF query If the Output is Outside of Tole
25. using the LAS ENAB OUTOFF command e Laser mode changes wile the output is on GPIB Section The GPIB section is located in the top right corner of the LDC 3900 Modular Laser Diode Controller front panel See Figure 2 1 on page 10 This section contains the LOCAL switch and the REMOTE and TALK LISTEN indicators The LOCAL switch is used for several functions as described below Sending any command over the GPIB bus automatically puts the instrument in REMOTE mode The REMOTE indicator identifies when the instrument is in remote operation mode When the instrument is in REMOTE mode pressing the LOCAL switch returns the instrument to LOCAL control mode unless a Local Lockout state has been activated by the low level GPIB command LLO from the host computer Local Lockout disables all LDC 3900 front panel switches until this condition is changed by the host computer In this condition the REMOTE indicator will flash at a 1 Hz rate 16 LDC 3900 Series im IL Lightwave OPERATION LDC 3900 Front Panel For more information on low level interface commands such as LLO refer to the IEEE488 1 specification When the instrument is in LOCAL mode pressing the LOCAL switch causes the GPIB address to be displayed The GPIB address may be changed by turning the ADJUST knob while also pressing the PARAMETER SET switch The usable GPIB address range is 1 30 The TALK LISTEN indicator is illuminated whenever the instrument is communicati
26. 00 3 LDC 3900 Default Settings 000 eee eee 8 TEC Error Indicators 0 0 00 cece eee 24 Laser Error Indicators 1 0 2 0 ccc ee eee 31 State of the LDC 3900 After RST 000005 45 LDC 3900 Default Settings for Output Off Registers 70 Substitute Parameter Names 0000 02 cea eae 74 LDC 3900 Device Dependent Command Summary 75 Error Code Classifications ooooooommommo 181 LDC 3900 Modular Laser Diode Controller Error Message Codes182 Comparison of Curve Fitting Equations 186 LDC 3900 Series E List of Tables ix IM LX Lightwave LDC 3900 Series x SAFETY AND WARRANTY INFORMATION 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 M warning Warning indicates a potentially dangerous situation which can result in serious injury o
27. 10 LDC 3900 Series 175 COMMAND REFERENCE LDC 3900 Programming Examples This program example assumes that a laser and a monitor photodiode detector are properly installed and the detector responsivity is known to be 1 2 uA mW It also assumes the use of a subroutine for talking to the LDC 3900 over the GPIB see L l vs Temperature Example Program on page 176 100 CMDS Las Chan 2 GOSUB 1000 Set the LASER channel 300 CMDS Las Calmd 1 2 GOSUB 1000 Set the detector responsivity to 1 2 mA mW 310 CMDS Las Output OFF Las Mode MDP GOSUB 1000 Output off set to constant power mode 320 CMDS LAS LIM I 1000 GOSUB 1000 Set limit to 1000 mA 330 CMDS Las Output ON GOSUB 1000 Turn LASER output on 340 FOR X 1 TO 50 Take 50 measurements 350 CMD Delay 1000 Las MDP GOSUB 1000 Wait 1 second between readings 360 INPUT 2 PS Input is monitor photodiode power in mW 370 NEXT X L I vs Temperature Example Program The following example program is a BASIC program for use with the LDC 3900 Modular Laser Diode Controller It may be used to gather L I data laser output vs drive current at several different stabilized temperatures 10 x L I vs TEMP 20 30 This program measures laser light output vs drive current over several temperatures 40 It is intended for use with an LDC 3900 Modular Laser Diode Controller an IBM PC XT or compatible u
28. 31 39 49 57 decimal 8 bit data byte is defined as an 8 bit byte in the range 00 FF 0 255 decimal NL is a new line LF and END is an end or identify EOI This element is used only with a PUD command to the LDC 3900 Modular Laser Diode Controller lt PROGRAM DATA SEPARATORS gt When there is a list of lt PROGRAM DATA UNITS gt parameters following a lt PROGRAM HEADER SEPARATOR gt white space the lt PROGRAM DATA UNITS gt must be separated with a lt PROGRAM UNIT SEPARATOR gt The syntax 44 LDC 3900 Series im IX Lightwave REMOTE OPERATION ANSI IEEE 488 2 Definitions diagram for a lt PROGRAM UNIT SEPARATOR gt is shown in Figure 3 8 on page 45 lt white space gt lt white space gt Figure 3 8 lt PROGRAM DATA SEPARATOR gt Syntax Diagram Default Parameters There are no default values for omitted parameters If a command is expecting a parameter and none is entered an error will be generated However if a reset is performed via a RST command or a RCL 0 command the following parameters will be set to the default state shown in Table 3 1 on page 45 Table 3 1 State of the LDC 3900 After RST LDC 3900 Condition GPIB in local via front panel in remote via GPIB ParameterS not selected TEC and or Laser adjust not selected TEC output off TEC Display enabled in T mode Constant T mode selected TEC Display sh
29. 5 00 mW of PD feedback optical power for channel 1 1 00 mW for channel 2 2 00 mW for channel 3 and 4 00 mW for channel 4 04_10 LDC 3900 Series 91 92 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL LIMit MDP Parameters Notes Examples DEVICE DEPENDENT The LASer ALL LIMit MDP query returns the values of the laser monitor PD power limit for all four channels None The response is four lt nrf value gt s separated by commas one from each channel in ascending order A response of INF for any given channel means that the parameter is not valid for that channel could be the wrong type of module The power limit setting accuracy depends on the accuracy of the CALMD setting for proper conversion of monitor current to power LAS ALL LIM MDP response 3 0 2 5 1 5 1 0 means the monitor PD power limit is set to 3 0 mW for channel 1 2 5 mW for channel 2 1 5 mW for channel 3 and 1 0 mW for channel 4 LAS Limit MDP response 10 0 means the selected channel s monitor PD power limit is set to 10 0 mW LASer ALL MDI Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT The LASer ALL MDI command sets for all channels the optical power set point in mA if the CALMD CAL PD responsivity is 0 for a given channel Four lt nrf value gt s separated by commas which represent the photodiode feedback current in mA for each channel in ascending order If the a
30. ALL LIM 1 4 Used to set all the channels LASER constant current source limit values LAS ALL LIM 1 NONE Used to return all the channels LASER constant current source limit values LAS ALL LIM P 4 Used to set all the channels constant optical power from monitor PD limit values LAS ALL LIM P NONE Used to return all the channels optical power from monitor PD limit values LAS ALL MDI 4 Used to set all the channels constant optical power set points if PD responsivity is 0 LAS ALL MDI NONE Used to return all the channels monitor PD current measured values measured about every 600 mSec LAS ALL MDP 4 Used to set all the channels constant optical power set points if PD responsivity is non zero LAS ALL MDP NONE Returns all the channels actual monitor PD power values measured about every 600 mSec LAS ALL MODE NONE Returns all the channels LAS operating modes LAS ALL MODE IHB NONE Sets all the LAS channels to constant current high Ww bandwidth mode LAS ALL MODE ILB NONE Sets all the LAS channels to constant current low Ww bandwidth mode LAS ALL MODE MDP NONE Sets all the LAS channels to constant power mode LAS ALL ONLY OUT 4 Set all the channels LAS output only on or off Useful with combination modules LAS ALL OUT 4 Same action as setting all the LAS channel s OUTPUT switches on off LAS ALL OUT NONE Returns the OUTPUT switch status for all the LAS channels LAS CALMD 1 Used to set the pres
31. ANSI IEEE 488 2 Definitions The second part contains information on advanced programming techniques and status reporting The third part contains information on remote interface messages these low level messages are generally transparent to the user Preparation for Bus Control To use the LDC 3900 Modular Laser Diode Controller remotely you will need to install an IEEE 488 interface adapter in your host computer These adapters and support software are available from several manufacturers and can be installed in most computers This manual assumes that you have a basic knowledge of the GPIB IEEE 488 interface bus and how to use it for instrument control This chapter also assumes that you are familiar with the controls on the LDC 3900 Modular Laser Diode Controller Review Chapter 2 if you need more details on how to operate the LDC 3900 Modular Laser Diode Controller The talk and listen addresses on the LDC 3900 Modular Laser Diode Controller are identical This GPIB address is read locally by pressing the GPIB Local switch and reading the display To set the GPIB address press and hold in the Parameter Set switch while displaying the GPIB address Turn the Adjust Knob until the desired address value is displayed then release the Set switch The new GPIB address will then be stored in non volatile memory independent of the Save and Recall bin number The allowable address range is 0 30 for primary GPIB addressing It is not nor
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33. Comm DEVICE DEPENDENT FRONT PANEL The TEC ITE query returns the value of the measured TEC output current for the selected TEC channel Parameters None The response value represents the measured ITE current in Amps Notes The TEC load current is constantly measured and updated regardless of the TEC mode of operation This measurement is updated approximately once every 600 msec If an external booster is used the ITE measurement will remain zero as the internal output section is disabled in that case In local operation the ITE measured value is determined by pressing the ITE switch in the TEC DISPLAY area of the front panel and visually reading the value on the TEC display Examples TEC ITE response 2 43 means the measured TEC output current is 2 430 Amps for the selected TEC channel Tec lte response 3 27 means the measured TEC output current is 3 270 Amps for the selected TEC channel TEC LIMit Commo DEVICE DEPENDENT FRONT PANEL The TEC LIMit command path is used to get to the selected TEC channel s TEC limit commands The following commands may be reached directly from the TEC LIMit command path TEC LIMit ITE TEC LIMit ITE TEC LIMit THI TEC LIMit THI TEC LIMit ITE COMN DEVICE DEPENDENT FRONT PANEL The TEC LIMit ITE command sets the TEC TE current limit value for the selected TEC channel Parameters An lt nrf value gt representing the limit value of the TE current in Amps for the sele
34. DEC COMM DEVICE DEPENDENT The LASer DEC command decrements the selected laser control mode set point by one or more steps Optional parameters allow multiple steps to be decremented and the time in milliseconds between decrements to be set respectively Parameters None 1 or 2 Notes The decremental default amount is one step The step size can be edited via the LAS STEP command its default value is 1 0 mA 1 0 mW or 1 mA if CALMD 0 depending on the mode of operation If the first optional parameter is used but not the second the user may decrement the LASER set point by a multiple of the LAS STEP size without changing the LAS STEP size If the both optional parameters are used the user may create an automated stepping ramp function for the LASER output If the first optional parameter is entered as zero LAS DEC 0 the command will do nothing The number of steps parameter must be an integer between 0 and 65535 The minimum time to complete one decrement is about 10 to 20 mSec Therefore values for the second optional parameter time between decrements have a practical minimum of 20 The maximum number of mSec is 65535 Examples LAS MODE l LAS STEP 0 3 LAS DEC action The laser source current set point is decremented by 0 3 mA LAS MODE l LAS STEP 0 3 LAS DEC 3 action The laser source current set point is decremented by 0 9 mA 0 3 mA 3 LAS MODE l LAS STEP 0 3 LAS DEC 3 5000 action The laser source curre
35. LASER current tolerance setting of 0 2 mA with a time window of 5 000 seconds LASER TOL response 1 0 20 0 means the selected LAS channel has a LASER current tolerance setting of 1 0 mA with a time window of 20 000 seconds 04 10 LDC 3900 Series 127 COMMAND REFERENCE LDC 3900 Device Dependent Commands MESsage Parameters Notes Examples DEVICE DEPENDENT The MESsage command allows the user to enter an ASCII string of up to 16 non zero characters This command may be useful for storing messages which relate to a test or configuration An ASCII string that is 1 16 bytes in length The message may contain any ASCII character but will be terminated when a NULL terminator character is received If the message has less than 16 bytes the software will fill the remaining message space with the space character After 16 bytes have been entered the software will null terminate the string MESSAGE This is a test action The string This is a test will be stored in non volatile memory Mes Test 3 action The string Test 3 will be stored in non volatile memory MESsage Parameters Notes Examples DEVICE DEPENDENT The MESsage query returns the previously stored message This message will always be 16 bytes long and enclosed in quotes The message is entered via the MESsage command None The response is a 16 byte long character string The response data will be a 16 byte long string I
36. MODULATION Input Connector Earth Feed through from front sround CHANNEL LOCATIONS MODULATION 4 3 2 1 LA FROM FRONT nin III IMU l Module Bays Far Optional AC Power Fuse PIB Entry Modul Figure 2 25 LDC 3900 Rear Panel GPIB Connector The GPIB connector is located on the back panel between the fan and the AC Power Entry Module 04_10 LDC 3900 Series 33 OPERATION _ General Operating Procedures Modulation from Front Connector The Modulation from Front connector allows a modulation signal to be passed from the front panel to the back and jumpered to a Laser module in one of the four module bays See the Laser module instruction manual for details on modulation Earth Ground Connector The LDC 3900 provides an earth ground connector for your convenience It is located above the AC Power Entry Module The TEC and Laser outputs are isolated from chassis ground Refer to the module instruction manuals for information concerning grounding General Operating Procedures The following sections present some guidelines for operation as well as some common operating procedures Remote operations are discussed in Chapter 4 Warm up and Environmental Considerations Operate the LDC 3900 Modular Laser Diode Controller at an ambient temperature in the range of 0 to 40 xC St
37. PARAMETER GMINDLASER O LMI te LMI o O LMT n LMP o SELECT CONST CALPD O O GAIN O SAVE SET RECALL o Figure 2 6 Parameter Section The Save and Recall parameter functions are used to quickly configure the LDC 3900 Modular Laser Diode Controller s parameters to user determined preset values In order to use these functions none of the Adjust modes TEC and Laser can be enabled Adjust TEC and Adjust Laser Indicators not orange With neither Adjust mode selected pressing the Parameter Select switch will cycle between the Save and Recall parameter functions The Parameter Set switch is used to enter Save and Recall values in a similar manner as with the other parameters For more information see Save and Recall Parameter Functions on page 31 When the unit is powered up the parameters will automatically be restored to the same values that were present at the last power down if possible Furthermore all of the saved setups will be remembered and easily recalled TEC Functions This section gives a brief synopsis of the TEC controller sections on the LDC 3900 Modular Laser Diode Controller front panel Once a TEC channel is selected via the Adjust LAS TEC switches all of the TEC functions will pertain to that TEC channel only The TEC Mode section is used to select the output control mode for the selected TEC channel Repeatedly pressing the TEC Mode Select switch cycles through the con
38. RCL command SRE The Service Request Enable command sets the Service Request Enable Register bits to allow the LDC 3900 to generate the user selectable service requests 04 10 LDC 3900 Series 57 REMOTE OPERATION Common Commands and Queries The syntax of the SRE command is OQO Ly lt white lt DECIMAL space gt tj NUMERIC PROGRAM DATA gt where the value of the numeric data rounds off to an integer between 0 and 255 The value of the numeric data corresponds to the bits enabled Standard Event Summary ESB Error Queue Not Empty MAV Message Available ASER Condition Summary ASER Event Summary TEC Condition Summary TEC Event Summary 5 14 3 2 1 0 Status Byte Service Request SRQ Logical OR 17 X15 4 3 2 1 0 Service Request Enable Register Figure 3 10 Service Request Enable Register 58 LDC 3900 Series MIL Lightwave REMOTE OPERATION Common Commands and Queries Bit Reference 0 TEC Event Summary 4 Message Available 1 TEC Condition Summary 5 Event Status Summary 2 LASER Event Summary 6 Request Service Master Status Summary 3 LASER Condition Summary 7 Error Message Available SRE The Service Request Enable query allows the user to determine the current contents of the Service Request Enable Register When this query is made the response is the binary integer value of the contents of the register see Fig
39. Ready for Calibration Data 16 TEC Interlock Enable 4096 Calculation Error 32 Booster Enable 8192 Internal Communication Error with TEC Board 64 Sensor Open 16384 Software Error 128 TE Module Open 32768 TEC EEPROM Checksum Error Notes The enabled TEC conditions for the selected TEC channel can be read by using the TEC ENABle COND query The TEC condition status for the selected TEC channel can be monitored by the TEC COND query If any of the enabled TEC conditions are true bit 1 of the status byte register will be set The enable registers normally retain their values at power up as they were at power down unless the power on status clear flag is set true see PSC Chapter 3 Examples TEC ENAB COND 513 action enables the TEC status condition register so that the Output Out of Tolerance and TE Current Limit conditions for the selected TEC channel will be reported in the status byte register Tec Enable Cond HFDFB action enables the TEC status condition register for the selected TEC channel so that any and all of the above conditions will be reported in the status byte register 04 10 LDC 3900 Series 151 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ENABle COND COMMON DEVICE DEPENDENT The TEC ENABle COND query returns the value of the status condition enable register of the TEC operations for the selected TEC channel Parameters None The response is the sum of the following 1
40. TE Current Limit 256 N A 2 Voltage Limit Error 512 Output Out of Tolerance 4 N A 1024 Output On 8 High Temperature Limit 2048 Ready for Calibration Data 16 TEC Interlock Enable 4096 Calculation Error 32 Booster Enable 8192 Internal Communication Error with TEC Board 64 Sensor Open 16384 Software Error 128 TE Module Open 32768 TEC EEPROM Checksum Error Notes The enabled TEC conditions for the selected TEC channel can be set by using the TEC ENABle COND command The enabled TEC condition status for the selected TEC channel can be monitored by the TEC COND query Examples TEC ENAB COND response 129 means that the TE Module Open and TE Current Limit conditions for the selected TEC channel may be reported in the status byte register Radix Hex TEC Enable Cond response HFDFB means that any and all of the above conditions for the selected TEC channel will be reported in the status byte register 152 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ENABle EVEnt COMMON DEVICE DEPENDENT RONT PANE EL The TEC ENABle EVEnt command sets the status event enable register of the TEC operations for the selected TEC channel These events are summarized in bit 0 of the status byte register Parameters An lt nrf value gt whose sum represents the enabled bits 1 TE Current Limit 256 N A 2 Voltage Limit Error 512 Output Changed to be In Out of Toleranc
41. The Indicator becomes lit when laser drive current is displayed When the switch is pressed the display will show measured laser current in mA If the Laser Display Set switch is then pressed and mode is selected in the Laser Mode section the display will show the laser current set point value in mA The Ipp Ppp Indicator becomes lit when monitor photodiode current or power is displayed When the Ipp Ppp switch is pressed the Laser display will show measured monitor PD current in uA or measured monitor PD power in mW if the CAL PD value is non zero see CAL PD on page 29 Pressing the Ipp Ppp switch again will toggle between current and power measurements If the CAL PD parameter value is zero the Laser display will indicate when the Ppp display is selected LDC 3900 Series 27 OPERATION _ LDC 3900 Front Panel The V Indicator becomes lit when a laser voltage measurement is displayed When the V switch is pressed the display will show measured laser voltage in volts There is no set point for laser voltage The Laser Display Set Indicator becomes lit when the display is showing the Set set point value The Laser Display Set Indicator goes off when the display is showing a measured value Laser Parameter Section The Laser switch for the desired channel in the Adjust section must be engaged illuminated orange to adjust the Laser Parameter values The following sections describe the function and
42. The default conditions may be recalled by using the RST command The default conditions are outlined in Default Parameters on page 45 lt nrf value gt The symbol lt nrf value gt refers to the flexible numeric representation as defined by the IEEE 488 2 standard All this means is that numbers may be represented in one of three forms integer floating point or engineering scientific notation For example the number twenty can be represented by an ASCII string of 20 or 20 20 0 or 20 0 2 0E 1 or 2 0E 1 or 2 0e 1 or 2 0e 1 These three forms are denoted NR1 NR2 and NR3 respectively by the IEEE 488 2 standard For more information on the precise syntax of these definitions refer to the IEEE 488 2 standard lt PROGRAM MESSAGE TERMINATOR gt When you send a command using the standard format the host computer or GPIB driver usually puts a lt CR gt lt NL gt lt END gt carriage return line feed EOl on the data bus following the command string The IEEE 488 2 standard requires either lt NL gt lt END gt lt NL gt or lt END gt as an acceptable lt PROGRAM 40 LDC 3900 Series im IL Lightwave REMOTE OPERATION ANSI IEEE 488 2 Definitions MESSAGE TERMINATOR while the lt CR gt is treated as lt white space gt ignored The LDC 3900 Modular Controller will accept any lt PROGRAM MESSAGE TERMINATOR gt shown in Figure 3 2 on page 41 The LDC 3900 Modular Laser Diode Controller terminates its
43. amps for the selected TEC channel 166 LDC 3900 Series im IL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC SET R Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The TEC SET R query returns the selected TEC s constant thermistor resistance or linear sensor reference set point value None The response represents the selected channels s set point thermistor or RTD resistance value in kW or the AD590 set point current in mA or the LM335 set point voltage in mV The selected TEC output is controlled to this set point value only when constant R mode is in effect In local operation the R set point value is read by pressing the TEC DISPLAY SET switch while in R mode and visually reading the TEC display TEC SET R response 3 4 means the R set point is 3 400 kW or 3 40 mA or 3 4 mV depending on the SENSOR SELECT switch position for the selected TEC channel Tec Set R response 4 0 means the R set point is 4 000 kW or 4 00 mA or 4 0 mV depending on the SENSOR SELECT switch position for the selected TEC channel TEC SET T Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The TEC SET T query returns the TEC constant temperature set point value in C None The response represents the set point temperature in C for the selected TEC channel The selected TEC output is controlled to this set point value only when constant T mode is in
44. as the Laser Mode but Ipp is selected in the Laser Display switch section and the photodiode current is displayed on the Laser display If the Adjust Knob is turned the Laser display will then show the Laser current set point for three seconds After three seconds the Laser display will revert to showing the measured Ipp value Note In the Laser Display switch section the Ipp Ppp display mode corresponds to the P control mode while the display mode corresponds to either or lygy control modes of the Laser Mode section The V display mode does not correspond directly to any control mode Output Section The Output 1 4 switches are used for turning the LAS and TEC outputs on and off The Output switch has a toggling action Push it once to turn the LAS and or TEC output on and push it again to turn the LAS and or TEC output off The LAS and TEC outputs are off whenever the unit is first powered up and the LAS or TEC outputs are toggled off whenever the LAS or TEC control modes are switched For channels which have a combined LAS and TEC controller module see the module manual for specifics on controlling the outputs The Output 1 4 indicators become lit when the corresponding LAS and or TEC output is on For channels which have a combined LAS and TEC controller module refer to the module manual for specifics on the Output Indicator TEC Mode Section The TEC Mode selection determines which parameter is used to control the o
45. command to determine if its waiting for a value If the response is 1 the LDC 3900 is ready to receive a calibration value via the TEC ITE command see the Calibration section of the TEC module instruction manual This query may then be repeated for the second half of the calibration cycle A query of the TEC condition status register bit 11 has the same results In local operation the ready state during the calibration cycle is indicated by a beep which is issued by the LDC 3900 when it is ready for a value to be entered if the beeper is enabled Tec CAL ITE response 1 means the LDC 3900 is ready for the user to enter a current value via the TEC ITE command Tec Cal lte response 0 means the LDC 3900 is not yet ready for the user to enter a current value or it is not in the TEC current calibration cycle TEC CAL SENsor Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT FRONT PANEL The TEC CAL SENsor command sets the TEC s sensor calibration mode for the activated via the rear panel switch sensor on the selected TEC channel and it enters that mode None After this command is issued the front panel is disabled and the LDC 3900 will automatically enter the sensor calibration mode When the LDC 3900 is ready the SET switch will become enabled and the user should enter the true measured value This procedure is outlined in the Calibration section of the TEC module instruction manual In remote ope
46. determined by visually inspecting the LED indicators in the TEC MODE area of the front panel lit ON Examples Tec MODE response ITE means that constant ITE current mode is in effect for the TEC output for the selected TEC channel TEC Mode response R means that constant R resistance reference mode is in effect for the TEC output for the selected TEC channel Tec Mode response T means that constant T temperature mode is in effect for the TEC output for the selected TEC channel TEC MODE Con DEVICE DEPENDENT FRONT PANEL The TEC MODE command path is used to get to the selected TEC channel s TEC mode selection commands The following commands may be reached directly from the TEC MODE command path TEC MODE ITE TEC MODE R TEC MODE T LDC 3900 Series 161 162 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC MODE ITE Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The TEC MODE ITE command selects TEC constant TE current mode for the selected TEC channel None This mode keeps the TEC current constant regardless of load temperature variations on the selected TEC channel Changing modes causes the output to be forced off and the new mode s set point value will be displayed for the selected TEC channel In local operation the TEC control mode is set by pressing the TEC MODE SELECT switch until the desired mode is indicated by corresponding LED lit ON
47. display is set for the current set point and 2 the Laser output is turned on Laser display set out on The command out is first searched at the LAS DIS level Since the command LAS DIS OUT does not exist the next higher level LAS is searched There the command LAS OUT is found and the parameter on is legal so there is no error Care must be taken to avoid errors which are caused by trying to implement commands from the wrong path or level For example the following command string was intended to 1 read back the set point resistance and 2 read back the measured resistance TEC Set R R Instead the output would return the set point resistance twice When the second R is found the software will first search for that command at its current level 04_10 LDC 3900 Series 61 REMOTE OPERATION Advanced Programming Since it finds it there it will be executed If this command did not exist at this level the software would search down to the TEC level and find and execute the intended command TEC R In order to ensure the proper command is executed for the example above the following command string should have been issued TEC Set R TEC R Once the software has walked to a lower path level it remains at that level when it receives the next command For example to 1 set the Laser display to show the set point 2 decrement the set point and 3 set the TEC display
48. for the selected LAS channel Parameters None The response will be either 1 ready or O not ready Notes After this query is issued and a response of 1 is received the LDC 3900 Modular Laser Diode Controller be ready for the user to enter a current value via the LASer MDI command see the Calibration the LASER module instruction manual In local operation the ready state during the calibration cycle is indicated by a beep which is issued by the LDC 3900 Modular Laser Diode Controller when it is ready for a value to be entered Examples LAS CAL MDI response 1 means the LDC 3900 Modular Laser Diode Controller is ready for the user to enter a photodiode current value via the LASer IPD command for the selected LAS channel Laser Cal Mdi response 0 means the LDC 3900 Modular Laser Diode Controller is not yet ready for the user to enter a photodiode current value for the selected LAS channel 100 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer CHAN COMMON DEVICE DEPENDENT FRONT PANEL The LASer CHAN command selects the LASER channel for LASER display and adjustment Parameters An lt nrf value gt where the lt nrf value gt 1 4 represents an LDC 3900 channel number Notes Selecting a valid LASER channel will allow that channel s LASER current source to be adjusted and displayed from the front panel After a LASER channel is selected all of the LAS commands will
49. for the selected channel s laser output LASer MODE DEVICE DEPENDENT FRONT PANEL The LASer MODE command path is used to get to the selected LAS channel s laser mode selection commands The following commands may be reached directly from the LASer MODE command path LASer MODE IHBW LASer MODE ILBW LASer MODE MDP LASer MODE IHBW DEVICE DEPENDENT FRONT PANEL The LASer MODE IHBW command selects laser high bandwidth constant current mode for the present LAS channel Parameters None Notes In local operation the constant mode is selected by pressing the LASER MODE SELECT switch until the IHBW indicator is lit Examples las mode ihbw action enables the laser high bandwidth constant current mode for the selected LAS channel LAS Mode hbw action enables the laser high bandwidth constant current mode for the selected LAS channel 120 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer MODE ILBW COMM DEVICE DEPENDENT FRONT PANEL The LASer MODE ILBW command selects laser constant current mode Parameters None Notes Constant mode low bandwidth enables the selected channel s output low bandpass filter In local operation the constant mode is selected by pressing the SELECT switch in the LASER MODE area of the front panel until the indicator is lit Examples LAS MODE ILBW action sets the selected channel s laser output for constant
50. given channel s CALMD CAL PD parameter is not set to 0 the corresponding LAS ALL MDI value will not be used In this case the measured MDI would be converted to MDP PPD by the CAL PD factor and the MDP PPD set point would be used on that channel Las ALL Mdi 40 40 40 40 action The LASER output is controlled so that the photodiode feedback current remains constant at 40 mA on all four channels Laser All MDI 200 100 30 30 action The LASER output is controlled so that the photodiode feedback current remains constant at 200 mA on channel 1 100 mA on channel 2 and 30mA on channels 3 and 4 MIX Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL MDI DEVICE DEPENDENT The LASer ALL MDI query returns the values of the laser photodetector current measurement in mA for each channel Parameters None The response is four lt nrf value gt s one for each channel in ascending order Notes The responses are in mA A response is valid even when the channel is not in constant P mode as long as the module type is correct some combination modules do not support constant MDI MDP mode This measurement is updated approximately once every 600 mSec per channel Examples Las ALL Mode MDP Las All Calmd 0 0 0 0 Las all MDi response 100 0 0 0 0 0 0 0 means 100 mA of photodetector current from channel 1 This feedback is controlling the laser selected channel s current output The measurement of
51. in mA for the AD590 setting and kW for the RTD The ITE indicator becomes lit when the unit is in the TEC drive current control mode When the unit is in constant TEC current mode the TEC is controlled to the constant lyg set point value TEC Display Switch Section The TEC Display switch section is used to select the TEC display mode Either the set point or measured T temperature R resistance reference or lyg TEC 04 10 LDC 3900 Series 19 OPERATION LDC 3900 Front Panel current values may be selected to appear on the TEC display The set point mode is determined by the TEC Mode selection Any of the measured TEC values may be displayed by pressing the desired TEC Display switch When a measurement display mode T R or ITE is selected by pressing its switch the TEC Display Set Indicator LED will go off if previously on Refer to Figure 2 8 on page 13 for the discussion of the TEC Display switch section features TEC DISPLAY TE Figure 2 17 LDC 3900 TEC Display Switch Section TEC Display Set When the TEC Display Set switch is pressed the TEC Display Set switch Indicator and the TEC Display Indicator of the set point mode T R or lyg will become lit if they are not already lit The set point may then be changed by turning the Adjust Knob within three seconds of releasing the TEC Display Set switch The TEC Display Set switch may be held in while
52. inadvertently changed Front Panel Notice in Figure 2 1 that the TEC functions are on the left side and the Laser functions are near the center of the front panel Functions which are common to both TEC and Laser such as GPIB or Adjust are on the right side of the front panel Note also that the Parameter area is divided into TEC and Laser components The TEC parameters are on the left and the Laser parameters are on the right while the common Save and RecallRecall parameters are at the bottom 04_10 LDC 3900 Series 9 OPERATION LDC 3900 Front Panel Refer to Figure 2 1 for the following discussions of the LDC 3900 Modular Laser Diode Controller front panel sections The key words are in bold type for quick identification Error LASER DISPLA Hl Indicators Sectior acto Displa Display Sectior MENOS iate Loc 3909 MODULAR LASER DIODE CONTROLLER Vv p AD JUST S A CPS a LASER TS CHANNEL ko CHANNEL a mw y i N E REMOTE 3 o AAA ope YOAGG MON 0 oe Tas UU na UU 7 v y Somos repr C ve CURRENT un emon E orewoncun E CURRENT MT w pmm HODULATION a C SENSOR OPEN C TE MODULE OPEN O INTLK ENBL C OUTPUT SHORTED CO POWER LIMIT ae ER Las tas tas Las IN POWER LASER DISPLAY mmm wee Cc l alll ee p TEC DISPLAY o o o o ar o o o 1 THROUGH TO REAR
53. into non volatile memory If the Parameter Set switch is pressed while the unit is in Select mode the unit will enter Set mode While the Parameter Set switch is held in the selected parameter value can be change by rotating the Adjust Knob The new value is stored in non volatile memory when the Parameter Set switch is released LIM The LIM parameter is used to set the absolute upper limit for Laser output current During operation when the Laser current limit is reached the CURRENT LIMIT Error Indicator flashes If the optional GPIB is implemented the Laser current limit condition may be used to turn the Laser output off via the LASer ENABle OUTOFF command The LIM Indicator becomes lit when the low range laser current limit is displayed The current limit setting is independent of the voltage drop of the device connected to the Laser output and therefore no dummy load is required for precise adjustment of the current limit 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 LIM P The LIM P is the absolute limit of optical power as detected by the unit via the monitor PD feedback scheme In order for this limit to be meaningful the monitor photodiode responsivity CAL PD must be adjusted correctly See CAL PD on page 29 This limit is a software limit only The Laser output is normally t
54. is ready to receive a calibration value via the TEC V command see the Calibration section of the 39034 module instruction manual A query of the TEC condition status register bit 11 has the same results Examples Tec CAL V response 1 means the LDC 3900 is ready for the user to enter a resistance value via the TEC V command Tec Cal V response 0 means the LDC 3900 is not yet ready for the user to enter a TEC voltage value 04_10 LDC 3900 Series 143 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC CHAN COMMON DEVICE DEPENDENT FRONT PANEL The TEC CHAN command selects the TEC channel for TEC display and adjustment Parameters An lt nrf value gt where the lt nrf value gt 1 4 represents an LDC 3900 channel number Notes Selecting a valid TEC channel will allow that channel s TEC current source to be adjusted and displayed from the front panel After a TEC channel is selected all of the TEC commands will apply to that channel If an invalid TEC channel is selected an E433 error will be generated and the TEC channel will not be changed Examples Tec chan 1 T action selects channel 1 for TEC display and adjustment the response will be the measured temperature from channel 1 assuming channel 1 contains a TEC module TEC Chan 4 Tec Out On action selects channel 4 for TEC display and adjustment turns on the output of the TEC module in channel 4 if possible TEC CHAN COMMON D
55. limit is set to 3 500 amps for channels 1 and 2 and the TEC current limit is set to 1 500 amps for channels 3 and 4 Tec All Limit lte 4 0 1 1 2 action the TEC current limit is set to 4 000 amps for channel 1 1 000 Amps for channels 2 and 3 and 2 000 Amps for channel 4 04_10 LDC 3900 Series 133 134 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL LIMit ITE Parameters Notes Examples DEVICE DEPENDENT The TEC ALL LIMit ITE query returns the values of the TECs TE current limit for each channel in ascending order None The response will be four lt nrf value gt s one for each channel in ascending order The response values are in Amps TEC ALL LIM ITE response 3 5 3 5 3 5 3 5 means the TEC output current limit is 3 500 Amps for all channels Tec All Limit lte response 4 0 3 0 1 0 1 0 means the TEC output current limit is 4 000 Amps for channel 1 3 000 Amps for channel 2 and 1 000 Amps for channels 3 and 4 LDC 3900 Series TEC ALL LIMit THI Parameters Notes Examples DEVICE DEPENDENT The TEC ALL LIMit THI command sets the TEC high temperature limit value for each TEC channel in ascending order Four lt nrf value gt s which represents the upper bound of the TEC load temperature in C for each channel in ascending order The THI limit values must be in the range 0 199 9 C If an entered value is greater than 199 9 an error E222 will be gen
56. lit if it is not already lit The set point may then be changed by turning the Adjust Knob within three seconds of releasing the Laser Display Set switch The Laser Display Set switch may be held in while the Adjust Knob is being turned but it is not necessary Three seconds after releasing the Adjust Knob or the Laser Display Set switch whichever occurs later the new value will be stored in non volatile memory and the Laser display will revert to the original display mode measured I lpp Ppp or V If the Laser Display is set to a mode that is different from the selected Laser Mode when the Adjust Knob is turned the Laser Display will automatically switch to the same mode selected in the Laser Mode section see Automatic Set Point Adjustment on page 17 The Laser Display Set mode is determined by the Laser Mode selection If it is desired to change a set point for a mode other than the present Laser Mode selection it is first necessary to select the desired Laser Mode see Laser Mode Indicators on page 26 When Laser Mode P is selected and the Laser Display Set switch is pressed the Laser Display Ipp Ppp Indicator LED will become lit If the CAL PD value is zero the Ipp set point will be displayed since the unit is in constant photodiode current mode If the CAL PD value is non zero the Ppp set point will be displayed since the unit is in constant photodiode power mode Laser Display Indicators and Switches
57. means power on was detected MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands RADix Parameters Notes Examples DEVICE DEPENDENT The RADix query allows the programmer to determine which radix type for status condition and event query response data is currently selected Decimal binary octal and hexadecimal are allowed None The response will be character data A response of DEC means decimal BIN means binary HEX means hexadecimal and OCT means octal DEC is the default type The LDC 3900 Modular Laser Diode Controller defaults to this radix at power up The RADix command is used to select the desired radix Once it is changed the new radix will remain in effect until the power is shut off or a new RADix command is issued RAD response Dec means the selected radix is decimal rad response Hex means the selected radix is hexadecimal RADIX response Oct means the selected radix is octal SECURE DEVICE DEPENDENT The SECURE command allows the service technician access to the protected user data command PUD which is a common command This data is normally changed only at the factory and therefore the SECURE command is not needed by the user TEC DEVICE DEPENDENT FRONT PANEL The TEC command path is used to get to the LDC 3900 s thermoelectric cooler TEC source commands The following command paths may be reached from the TEC command path
58. message of E 512 or E 513 will be displayed See Table 5 2 in Chapter 5 for a description of the error messages 6 LDC 3900 Series MIL Lightwave 04 10 OPERATION Power Up Sequence After this test the unit is configured to the state it was in when the power was last shut off unless the LDC 3900 detects that there has been a change in its modular configuration i e a new module added In that case the default parameters would be used The LDC 3900 will display the recognized module types by illuminating the Adjust LAS TEC Indicators in green The Adjust LAS TEC switches are not engaged no orange indicators immediately after power up The user must push an Adjust LAS TEC switch corresponding to a green Adjust LAS TEC Indicator in order to select the desired operating and adjustment mode The user may choose to clear the parameters that appear by recalling BIN 0 either manually or through the GPIB When BIN 0 is called the front panel will be in the following state LDC 3900 Series 7 OPERATION CHAPTER 2 Power Up Sequence Table 2 1 LDC 3900 Default Settings Setting GPIB mode in LOCAL via front panel or in REMOTE via GPIB TEC output off TEC DISPLAY enabled in T mode Constant T mode selected TEC Display showing actual temperature if TEC module exists Temperature Set Point 0 xC Resistance Reference Set Point 1 1 uA or 1 mV depending on the SENSOR SELECT switch p
59. mode as well as T mode and ITE mode However tolerance is no longer a requirement for the LDC 3900 s definition of operation completeness Tolerance testing is not supported with the RTD sensor Parameters Two lt nrf values gt the first represents the set point tolerance with a range of 0 1 to 50 0 The units vary with mode In T mode the first parameter is the temperature tolerance in C with a range of 0 1 C to 50 0 C In R mode the first parameter is the reference tolerance and the units depend on the sensor type With thermistors the useful resolution of the first parameter is 1 0 and a setting of 1 represents 10 ohms and the range is 10 to 500 ohms With LM335 sensors the useful resolution is 0 1 anda setting of 1 0 represents 1 0 mV and the range is 0 1 to 50 0 mV With AD590 sensors the useful resolution is 0 1 and a setting of 0 1 represents 0 01 uA and the range is 0 01 to 5 00 UA In ITE mode the first parameter is ignored and the set point tolerance is fixed at 10 mA The second parameter represents the time window in seconds with a range of 0 001 to 50 0 seconds The default values are 0 2 and 5 respectively NOTE that for R mode with a thermistor sensor 0 2 is treated as essentially O ohms making it difficult to achieve tolerance Version 3 1 and higher of the LDC 3900 requires both parameters to be sent Prior versions of the LDC 3900 allowed the second parameter to be optional Notes This command may be us
60. modules this command effects only the TEC output With combination modules when only the TEC or LAS output is on the corresponding output LED will blink Examples TEC Only Out 1 action turns ON the TEC output for the selected channel LAS output on the selected channel is not effected TEC only OUT 0 action turns OFF the TEC output for the selected channel The LAS output on the selected channel is not effected 04_10 LDC 3900 Series 163 164 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC OUTput Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The TEC OUTput command turns the selected TEC output on or off An lt nrf value gt 1 on O off After the selected TEC output is turned on it may be useful to wait until the output is stable within tolerance before performing further operations on the selected TEC channel but it is not necessary In local operation the TEC output is toggled off and on by pressing the ON switch in the TEC MODE area of the front panel TEC OUTPUT 1 action turns the selected TEC channel s output on Tec Out 0 action turns the selected TEC output off Tec Out OFF action turns the selected TEC output off TEC OUTput COMMON Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT FRONT PANEL The TEC OUTput query returns the status of the OUTPUT switch for the selected TEC channel None The response is an lt nrf value
61. no PPD value can be calculated In local operation the CALMD CAL PD value can be read by selecting the CAL PD parameter and visually reading the LASER display Examples LASER CALMD response 0 means the selected LAS channel is set for operation in constant IPD mode if P mode is also selected Las Calmd response 1 1 means the selected LAS channel is set for operation in constant PPD mode if P mode is also selected and the responsivity is set to 1 10 mA mW 1 1 mA of photodiode feedback current represents 1 mW of optical power 04_10 LDC 3900 Series 97 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer CAL COMMON DEVICE DEPENDENT FRONT PANEL The LASer CAL command path is used to get to the selected LAS channel s laser calibration commands In local operation the LASER calibration mode is reached by pressing the GPIB LOCAL and LASER DISPLAY or IPD switches at the same time The following commands may be reached directly from the LASer CAL command path LASer CAL LDI LASer CAL LDI LASer CAL LDV LASer CAL LDV LASer CAL MDI LASer CAL MDI LASer CAL LDI Co DEVICE DEPENDENT FRONT PANEL The LASer CAL LDI command is used to enter the LASER current set point measurement and limit in low bandwidth mode calibration mode for the selected LAS channel Parameters None Notes Since the limit circuit is the same for both high and low bandwidth modes it is only calibrated when low
62. nrf value gt s one for each channel in ascending order 1 non zero on 0 off Notes After a channel s output is turned on it may be useful to wait until the output is stable within tolerance before performing further operations but it is not necessary TEC ALL OUTput COMMO DEVICE DEPENDENT The TEC ALL OUTput query returns the status of all the TEC channels OUTPUT switches in ascending order Parameters None The response is four lt nrf value gt s separated by commas 0 off 1 on Notes Although the status of the switch is on the corresponding channel s output may not have reached the set point value Examples Tec ALL OUT response 0 0 0 0 means that the OUTPUT switch is disabled OFF on all channels TEC All OUT response 1 0 0 0 means that the TEC OUTPUT switch is enabled for channel 1 TEC output is present for channel 1 for combination modules the TEC and or LAS output may be enabled For channels 2 4 the TEC outputs are off TEC ALL OUTput CoM DEVICE DEPENDENT The TEC ALL OUTput command turns the TEC outputs for each channel on or off The parameters are in ascending channel order Parameters Four lt nrf value gt s one for each channel in ascending order 1 on O off Notes After a given TEC output is turned on it may be useful to wait until the output is stable within tolerance before performing further operations on that TEC channel but it is not necessary For LAS TEC combination module
63. of the front panel The status of the IPD PPD switch is on if its indicator is lit and the SET indicator is not lit lit ON Examples LAS DIS MDI response 0 means that the LASER DISPLAY IPD PPD switch is not currently active or active but displaying power laser photodiode monitor current is not displayed Las dis MDI response 1 means that the LASER DISPLAY IPD PPD switch is currently active monitor PD current may be displayed for the selected LAS channel LASer DISplay MDP COMN DEVICE DEPENDENT FRONT PANEL The LASer DISplay MDP command sets the laser display to show the monitor photodiode power measurement Parameters None Notes The actual LASER PPD display is turned off automatically when another LASER DISPLAY selection is enabled In local operation the LASER PPD value is displayed by pressing the IPD PPD switch in the LASER DISPLAY area of the front panel If IPD mode appears press the switch again to toggle to the PPD value Examples Las Display MDp action enables the LASER display for photodiode power values for the selected LAS channel Laser Disp MDP action enables the LASER display for photodiode power values for the selected LAS channel 106 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer DISplay MDP COMM DEVICE DEPENDENT FRONT PANEL The LASer DISplay PPD query returns the status of the LASER DISPLAY IPD PPD switch P
64. ohms 1100 H HHH HH HAHAH HH 1110 PRINT G 1120 PRINT 1130 l I 1 1140 INPUT 1 T I R I 1150 IF R I lt 0 THEN GOTO 1180 1155 X l LOG R I Y 1 T 273 15 1160 PRINT USING HS I T I R I 1170 GOTO 1130 1180 N 1 1 1190 CLOSE 1200 REM e accumulate sums 1205 SX 0 SY 0 SXY 0 SXX 0 1210 FORI 1 TON 1220 SX SX X I 1230 SY SY Y I 1240 SXY SXY X 1 Y 1 1250 SXX SXX X I X I 1260 NEXT 1300 REM print out results 1310 C 2 N SXY SX SY N SXX SX SX 1320 C 1 SY C 2 SX N 04_10 LDC 3900 Series 189 carrer A The Steinhart Hart Equation 190 LDC 3900 Series 1620 PRINT 1630 G Key in C1 C2 1640 P HHH HARE 1650 PRINT G 1660 PRINT USING P C 1 1000 C 2 10000 1700 1702 C1 INT C 1 1000000 1000000 1704 C2 INT C 2 1E 07 1E 07 1710 PRINT 1712 PRINT 7 T T 1714 PRINT R ACTUAL CALC ERROR 1716 PRINT 22222225 sosisalas Sasso e ees maaana 1718 P HHH HEHEHE HH HH ae 1720 FOR L 1 TON 1730 X LOG R L 1740 TCALC 1 C1 C2 X 273 15 1760 PRINT USING P R L T L TCALC T L TCALC 1780 NEXT L MIX Lightwave APPENDIX B AD590 AND LM335 SENSOR CALIBRATION la a fa ll al amp El a El a a E Introduction The LDC 3900 Laser Diode Controller uses two constants C1 and C2 C3 is not used for calibrating linear thermal sensing devices such as the AD590 and the LM335 C1 is used as the linear or zero offset value and C
65. 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 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 3 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 a
66. queries are distinguished by the which begins each mnemonic The common commands and queries are listed in alphabetical order and a brief description of their functions is given For more information on these commands refer to an ANSI IEEE 488 2 1987 standards reference CAL This is the calibration query When it is sent the LDC 3900 performs the A to D calibration procedure After this query is sent the LDC 3900 responds with a message indicating that calibration has been completed successfully or unsuccessfully A response of 0 means no errors any other number means an error in calibration was detected An auto calibration is performed each time the LDC 3900 accumulates 10 minutes of inactive time since the last auto calibration 48 LDC 3900 Series MIL Lightwave REMOTE OPERATION Common Commands and Queries The syntax for the CAL query is LOLO PC CLS This is the Clear Status command It is used to clear the status event registers It may be used for example to clear the Event Status Register the Standard Event Status Register and the Error Queue before enabling SRQ generation from instrument events The syntax for the CLS command is A gt ESE This is the Standard Event Status Enable command This command enables the Standard Event Status Register to update bit 5 of the status byte The Structure of the Standard Event Status Enable Register and Standard Event Status Register are s
67. responses with a lt NL gt lt END gt unless the user changes the terminator via the TERM command lt white space gt NL NL Figure 3 2 lt PROGRAM MESSAGE TERMINATOR gt Syntax Diagram If you encounter problems with GPIB communications with the LDC 3900 Modular Laser Diode Controller refer to your GPIB driver manual for the exact syntax of the output terminator See also Appendix G lt PROGRAM MESSAGE UNIT SEPARATOR gt A lt PROGRAM MESSAGE UNIT SEPARATOR gt is used to separate sequential lt PROGRAM MESSAGE UNIT gt elements commands from one another within a lt PROGRAM MESSAGE The syntax for a lt PROGRAM MESSAGE UNIT SEPARATOR gt is shown in Figure 3 3 on page 41 lt white space gt Figure 3 3 lt PROGRAM MESSAGE UNIT SEPARATOR gt Syntax Diagram 04 10 LDC 3900 Series 41 y REMOTE OPERATION _ ANSI IEEE 488 2 Definitions lt PROGRAM HEADER SEPARATOR gt The lt PROGRAM HEADER SEPARATOR gt separates the lt COMMAND PROGRAM HEADER gt 3900 Modular Laser Diode Controller command from the lt PROGRAM DATA gt first parameter after the command In the case of the LDC 3900 Modular Laser Diode Controller a single white space must be used to separate the command from the first parameter Note however commands may be compounded see lt compound command program header gt on page 42 lt white space gt Figure 3 4 lt PROGRAM HEADER SEPARATOR gt Synt
68. temperature data 188 A small sample data file is included below as an example of the data format and end of data marker R 1 Temperature Resistance 20 97072 10 55326 0 32650 10 19899 20 12492 25 10000 30 8056 8 40 5326 4 50 3602 3 1 1 Run the STEIN1 program The best curve fitting values for C1 and C2 will be displayed Enter these numbers into the LDC 3900 Laser Diode Controller LDC 3900 Series 80 REM eee OTEN FERRER ERR e 90 REM 92 REM Rev 3 11 87 94 REM T is expressed in Kelvins 100 REM Least squares fit program to find the thermistor coefficients 110 REM C1 and C2 in the following equation 120 REM 130 REM 1 T C1 C2 In R 140 REM 200 REM 210 REM Variables 220 REM 230 REM Tfi R i temperature and resistance data values 240 REM 250 REM Y i 1 T i the dependent variable depends on R i 260 REM in the Steinhart Hart equation above 270 REM MIL Lightwave The Steinhart Hart Equation mare AL 280 REM X i In R I the value of the ith function of the independent 290 REM variable In R natural log of resistance 330 REM 1000 DEFDBL A Z 1010 DEFINT I J K L 1020 DIM R 400 T 400 Y 400 X 400 1030 PRINT What is the data file name INPUT D 1040 OPEN i 1 D 1050 REM read and echo T i R i from the data file 1060 REM terminate read on R 1 1070 l 0 1080 PRINT Data 1090 G Point Temperature Celsius Resistance
69. the Adjust Knob is being turned but it is not necessary Three seconds after releasing the Adjust Knob or the TEC Display Set switch whichever occurs later the new value will be stored in non volatile memory and the TEC display will revert to the original display mode measured T R or lre If the TEC Display is set to a mode that is different from the selected TEC Mode when the Adjust Knob is turned the TEC Display will automatically switch to the same mode selected in the TEC Mode section seeAutomatic Set Point Adjustment on page 17 The TEC Display Set mode is determined by the TEC Mode selection If it is desired to change a set point for a mode other than the present TEC Mode selection it is first necessary to select the desired TEC Mode see TEC Mode Indicators on page 19 TEC Display Indicators and Switches The T indicator becomes lit when temperature is displayed When the T switch is pressed the display will show measured temperature in xC If the Set switch is then pressed and T mode is selected in the TEC Mode section the display will show the temperature set point value in xC 20 LDC 3900 Series im IL Lightwave OPERATION LDC 3900 Front Panel The R indicator becomes lit when the thermistor resistance or sensor reference is displayed When the R switch is pressed the display will show the measured thermistor resistance in kW or the measured LM335 voltage in mV or the measured AD590 current in m
70. the LASER output terminals When a LASER output is off an internal short is placed across the output terminals If this occurs for the selected LAS channel it causes the OUTPUT SHORTED light to come on In local mode a LASER output is turned on or off by pressing the corresponding OUTPUT switch for the channel on the front panel Examples LAS 20 LAS OUT ON action sets the selected channel s laser output current to 20 mA and then turns the selected channel s output on Las Out 0 action turns the selected channel s laser output off MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer OUTput COMM DEVICE DEPENDENT FRONT PANEL The LASer OUTput query returns the status of the selected laser channel s OUTPUT switch Parameters None The response is an lt nrf value gt Notes Although the status of the switch is on the selected channel s output may not have reached the set point value For LAS TEC combination modules a response of 1 indicates that the output switch for that channel is enabled Either the TEC or LAS output or both may be on In the case of only the TEC or LAS output being on the corresponding OUTPUT led will blink In local mode the LASER channel s output status is read by visually reading the corresponding LED in the OUTPUT area of the front panel lit on Examples Las OUT response 0 means that the selected channel s OUTPUT switch is disabled devices may be safely di
71. the LDC 3900 will respond to all of them in the same output message if possible For example the user may enter the following command Mes Rad TEC T Err The response may appear in this manner TESTI DEC 25 0 0 70 LDC 3900 Series MIL Lightwave 04 10 REMOTE OPERATION Status Reporting All query responses are evaluated at the time the query is parsed and not at the time the response message is sent In most cases this does not create a problem since the time between parsing a query and sending its response is small unless the GPIB controller takes a long time to request the response LDC 3900 Series 71 REMOTE OPERATION Status Reporting 72 LDC 3900 Series MIX Lightwave CHAPTER COMMAND REFERENCE 5 B E a t8 a a El El a E a 155 E E a E This chapter is a guide to the syntax and usage of the various device dependent commands for the LDC 3900 Modular Laser Diode Controller It contains a reference section for all of the device dependent commands including those which may only be accessed via remote operation Therefore it is of primary interest to users who wish to utilize the GPIB option This chapter is divided into two parts The first part contains an overview of the remote commands and syntax used by the LDC 3900 Modular Laser Diode Controller The second part contains all of the LDC 3900 commands in alphabetical order The commands that emulate local front panel operation are d
72. the present channel s constant current source measured value measured about every 600 mS LDC 3900 Series 77 COMMAND REFERENCE _ LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION LAS LDV 1 Used to set the present channel s laser voltage value for calibration LAS LDV NONE Used to return the present channel s measured laser voltage value measured about every 600 mS LAS LIM 1 1 Used to set the present channel s LASER constant current source limit value LAS LIM 1 NONE Used to return the present channel s LASER constant current source limit value LAS LIM MDP 1 Used to set the present channel s constant optical power from monitor PD limit value LAS LIM MDP NONE Used to return the present channel s optical power from monitor PD limit value LAS MDI 1 Used to set the present channel s constant optical power set point if PD responsivity is 0 LAS MDI NONE Used to return the present channel s monitor PD current measured value measured about every 600 mSec LAS MDP 1 Used to set the present channel s constant optical power set point if PD responsivity is non zero LAS MDP NONE Returns the present channel s actual monitor PD power value measured about every 600 mSec LAS MODE NONE Returns the present channel s mode current IHBW c
73. the set point thermistor or RTD resistance to 20 5 kW or the AD590 current to 20 5 mA or the LM335 voltage to 20 5 mV for channel 4 The TEC output sensor is controlled to that value if the output is on on channel 4 138 LDC 3900 Series MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL R Parameters Notes Examples DEVICE DEPENDENT The TEC ALL R query returns the values of the TEC thermistor or RTD resistance or AD590 current or LM335 voltage measurement for all channels in ascending order None The response is four lt nrf value gt s one for each channel in ascending order The response values are the measured TEC thermistor or RTD resistance in kW or AD590 current in mA or the measured LM335 voltage in mV for the corresponding channel TEC load temperature is derived from the thermistor resistance or linear sensor reference measurement for the selected TEC channel Each measurement is updated approximately once every 600 msec per channel TEC ALL R response 10 543 10 557 9 94 12 145 means For channel 1 the measured TEC thermistor or RTD resistance is 10 543 kW or the measured AD590 current is 10 543 mA or the measured LM335 voltage is 10 543 mV depending on the SENSOR SELECT switch position For channel 2 the measured TEC thermistor or RTD resistance is 10 557 kW or the measured AD590 current is 10 557 mA or the measured LM335 voltage is 10 5
74. to show the measured temperature the following command string could be used LAS DIS Set DEC TECIDIS T When the DEC command is reached the software is at the LAS DIS level Since there is no DEC command there it walks back up to the LAS level and there it finds the LAS DEC command The reason that the full path including TEC must be specified for the last part TEC DIS T is that otherwise it would look for the DIS T command in the LAS DIS path not find it and generate error E 123 After the second semicolon is reached DEC the software will first look for the next word TEC at the current path Since it is not found it will walk back up the tree until it finds it at the root level Once the search walks up to the root level it will not walk down any other paths unless the path is specified The only exception to the rule described above is when common commands are used In that case the software remembers which level the user was at before the common command was found and it returns to that same level after finding and executing the common command Therefore the following command string is legal TEC DIS T WAI DEC Here 1 the display is set to show the measured temperature 2 the software waits for the previous command to be executed and 8 the set point is decremented one step Timing Considerations Although the shortcuts mentioned in Path Specification on page 61 reduc
75. 0 0 mA of photodetector current from channels 2 4 indicates that chose channels may have their outputs turned off LAS ALL MODE IHBW LAS ALL MDI response 20 0 30 5 12 7 25 6 means 20 mA of photodetector current from channel 1 30 5 mA from channel 2 12 7 mA from channel 3 and 25 6 mA from channel 4 However photodiode monitor current is not controlling the selected channel s laser output current on any of the channels due to the IHBW mode LASer ALL MDP DEVICE DEPENDENT The LASer ALL MDP command sets for all channels the value of the optical power set point in mW if the CALMD CAL PD responsivity is greater than zero Parameters Four lt nrf value gt s which represents the photodiode feedback power in mW for each channel in ascending order Notes If a given channel s CALMD CAL PD parameter is set to 0 the LAS ALL MDP value for that channel will not be used In this case the measured MDP for that channel would be invalid and the MDI IPD set point would be used for that channel Examples Las ALL Mdp 40 40 40 40 action The LASER output is controlled so that the photodiode feedback power remains constant at 40 0 mW on all channels Laser all MDP 200 100 200 100 action The LASER output is controlled so that the photodiode feedback current remains constant at 200 0 mW for channels 1 and 3 and 100 0 mW for channels 2 and 4 04 10 LDC 3900 Series 93 94 COMMAND REFERENCE LDC 3900 Device Dependent
76. 0 Modular Laser Diode Controller front panel Once a LAS channel is selected via the Adjust LAS TEC switches all of the LAS functions will pertain to that LAS channel only For more detailed information see Laser Mode Section on page 25 The Laser Mode section is used to select the output control mode Repeatedly pressing the Laser Mode Select switch cycles through the current 1 light power P or high bandwidth current lygy control modes The LED Indicators show the 14 LDC 3900 Series im IL Lightwave OPERATION LDC 3900 Front Panel selected mode Note not all modes are available with all modules In that case only the valid modes may be selected LASER MODE SELECT Figure 2 11 Laser Mode A constant lpp mode may be used when P mode is selected and the CAL PD parameter value is set to zero The Laser Display switch section is used to select the measured IPD or PPD values or the set point value The displayed set point is determined by the Laser Mode selection LASER DISPLAY O o O o l Ipp Pep Vv SET Figure 2 12 Laser Display The Laser Parameters are Laser current limit LIM I for output laser light power limit LIM P and monitor photodiode responsivity CAL PD for converting from monitor current to light power TEC GIO P ARAMETERGHEEEEDLASER O LMI te LIMI oO O LMT H LIM P oO KT CONST CALPD O O GAIN S
77. 1 3 10 30 100 or 300 is on the TEC display then release the Parameter Set switch When the Parameter Set switch is released the new value will be stored in non volatile memory TEC Channel Indicators When a TEC channel is selected for adjustment see Adjust Section on page 17 the corresponding TEC channel LED will be orange and the appropriate parameter or measurement for that channel will be displayed on the TEC display If a TEC channel which is not selected for adjustment has an error condition the TEC channel LED of the channel with the error will blink and the Error Indicator LED will also blink TEC Error Indicators The functions of the TEC Error Indicators are shown in Table 2 2 on page 24 Refer to Figure 2 19 on page 24 during the discussion of the TEC Error Indicators See Chapter 5 Error Messages for information The Error Indicator and Channel Indicator s blink whenever an error occurs on a TEC channel which is not presently selected CHANNEL kQ TEC A mmm KT ERROR Cl TEMP LIMIT C TE CURRENT LIMIT C SENSOR OPEN TE MODULE OPEN 1 2 3 4 Figure 2 19 LDC 3900 TEC Error Section Table 2 2 TEC Error Indicators Error Condition Action Temperature limit TEMP LIMIT light flashes at 1 Hz Open sensor Output off SENSOR OPEN indicator LED flashes at 1 Hz TE Current limit TE CURRENT LIMIT light flashes at 1 Hz TE Module Open TE MOD
78. 2 4 are set for PPD mode Channel 2 has a responsivity of 0 500 microamps milliwatt Channel 3 has a responsivity of 3 300 microamps milliwatt Channel 4 has a responsivity of 0 256 microamps milliwatt Las ALL Calmd response 1 1 1 1 1 1 1 1 means that all four LAS channels are set for operation in constant PPD mode if P mode is also selected On all four channels the responsivity is set to 1 100 mA mW 1 100 mA of photodiode feedback current represents 1 mW of optical power LASer ALL LDI DEVICE DEPENDENT The LASer LDI command sets the laser control current for all LAS channels Parameters Four lt nrf value gt s which represents the laser output current in mA for each corresponding channel in ascending order Notes The set point is the same for both low and high bandwidth output modes on any given channel Examples Las ALL LDI 40 50 0 12 action sets the laser output current to 40 0 mA on channel 1 50 0 mA on channel 2 0 0 mA on channel 3 and 12 0 mA on channel 4 LAS all Idi 0 0 0 100 action sets the laser output current to 0 0 mA on channels 1 3 and 100 0 mA on channel 4 LASer ALL LDI DEVICE DEPENDENT The LASer ALL LDI query returns the value of the measured laser current for the selected LAS channel Parameters None The response is four lt nrf value gt s corresponding to the four channels in ascending order Notes Response is the measured laser output current for either low or high band
79. 2 is used as the slope or gain adjustment Therefore C1 should be set to a nominal value of 0 and C2 should be set to a nominal value of 1 when the SENSOR SELECT switch is in the AD590 or LM335 positions In order to calibrate a linear sensor device the sensor must be operated at an accurately known stable temperature For example the sensor may be calibrated at 0 C if the sensor is placed in ice water until its temperature is stable A highly accurate temperature probe thermometer environmental chamber etc may also be used to determine the known temperature for calibration This appendix contains one and two point calibration methods for linear sensor devices These methods will work for either type of device AD590 Sensor The AD590 is a linear thermal sensor which acts as a constant current source It produces a current i which is directly proportional to absolute temperature over its useful range 50 C to 150 C This nominal value can be expressed as i 1pA K where i is the nominal current produced by the AD590 and K is in Kelvin The LDC 3900 Laser Diode Controller uses i to determine the nominal temperature Tn by the formula Tn i 1pA K 273 15 where T is in C MIX Lightwave LDC 3900 Series 191 i AD590 Sensor The temperature Ty which is displayed by the LDC 3900 Laser Diode Controller is first calibrated as follows Ta Cia Ca Th where C1 and C2 are the constants stored
80. 23 Figure 2 24 Figure 2 25 Figure 3 1 ist of Figu a El a El E E Ml E E a E LDC 3900 Front Panel 0000 c eee eee 10 GPIB Section ooccccccccc eee 10 Laser Enable Switch 000 c eee eee eee 11 AdjUSt Section encia Medea es eed ete 11 Output SeCHON cas ned ee ceded eee Paneer eee aed es 11 Parameter Section 0 000 c eee eee eee 12 TEC Mode 36202 o20k Miead i oe cris ARS 13 TEG Display curia 13 TEC Parameters Gruvan eeuna wesana eee ees 13 TEG Display caci n la Se ok 14 Laser Modo s cerrrrr ros arra pitied tare dhe ae edie 15 Laser Display iio a ee hele eee a we eee 15 Laser Parameters 0 0 0 c eee eee ete eee 15 Laser Display yerri ria GaN ne ae EE ea ee ee 15 MOGUIAHION series Oecd Ge rs Reece Re eters 16 LDC 3900 TEC Mode Section 2 000 ee eee 19 LDC 3900 TEC Display Switch Section 20 LDC 3900 TEC Parameter Section 04 21 LDC 3900 TEC Error Section 0000 cee eee 24 LDC 3900 Laser Mode Section 004 25 LDC 3900 Laser Display Switch Section 26 LDC 3900 Laser Parameter Section 28 LDC 3900 Laser Error Section 20 000s eeee 30 LDC 3900 MODULATION Section 04 31 LDC 3900 Rear Panel 0000 0 eee eee 33 White Space Syntactic Diagram 20 000 eae 40 LDC 3900 Series E E res a vii SF Ml et viii LDC
81. 3900 Series Figure 3 2 lt PROGRAM MESSAGE TERMINATOR gt Syntax Diagram 41 Figure 3 3 lt PROGRAM MESSAGE UNIT SEPARATOR gt Syntax Diagram 41 Figure 3 4 lt PROGRAM HEADER SEPARATOR gt Syntax Diagram 42 Figure 3 5 lt compound command program header gt Syntax Diagram 43 Figure 3 6 lt compound query program header gt Syntax Diagram 43 Figure 3 7 lt ARBITRARY BLOCK PROGRAM DATA gt Syntax Diagram 44 Figure 3 8 lt PROGRAM DATA SEPARATOR gt Syntax Diagram 45 Figure 3 9 Standard Event Status Register Standard Event Status Enable Register 50 Figure 3 10 Service Request Enable Register o o oo o oo 58 Figure 3 11 LDC 3900 Status Reporting Schematic Diagram 65 Figure 3 12 An LDC 3900 LASER Module Output Off Register 68 Figure 3 13 An LDC 3900 TEC Module Output Off Register 69 Figure 4 1 Command Path Tree Structure oooooccoccocooooo 84 Figure A 1 Thermistor Resistance vs Temperature 187 Figure B 1 AD590 Nonlinearity 00 eee eee 192 IL Lightwave MiLxX Lightwave Table 1 1 Table 1 2 Table 1 3 Table 1 4 Table 2 1 Table 2 2 Table 2 3 Table 3 1 Table 3 2 Table 4 1 Table 4 2 Table 5 1 Table 5 2 Table A 1 a El a El E E LDC 3900 Options ooococococcco 2 LDC 3900 Options and Accessories oooooooooo ooo 2 GPIB Specifications ooooooooocooronooommmoo 3 General Specifications 00
82. 5 2 LDC 3900 Modular Laser Diode Controller Error Message Codes 184 Error Code Explanation E 519 Setting a measurement is only valid during the calibration phase for that measurement User has tried to calibrate a measurement without first entering the required calibration mode E 520 User cannot change the Laser Current set point while operating in a calibration mode for another measurement E 533 Attempted to perform an operation which the LASER channel was not capable E 534 Change of a LAS limit value forced an update of the corresponding LAS set point LDC 3900 Series MIX Lightwave APPENDIX A STEINHART HART EQUATION 5 B E a ta a El a a E El E a E E E E The Steinhart Hart Equation Two terminal thermistors have a nonlinear relationship between temperature and resistance The resistance verses temperature characteristics for a family of similar thermistors is shown in Figure A 1 It has been found empirically that the resistance versus temperature relationship for most common negative temperature coefficient NTC thermistors can be accurately modeled by a polynomial expansion relating the logarithm of resistance to inverse temperature The Steinhart Hart equation is one such expression and is given as follows 1 T A B L R C L R J3 Equation Where T is expressed in KELVIN Once the three constants A B and C are accurately determined Equation 1 introduces small errors in th
83. 57 mV depending on the SENSOR SELECT switch position For channel 3 the measured TEC thermistor or RTD resistance is 9 940 kW or the measured AD590 current is 9 940 mA or the measured LM335 voltage is 9 940 mV depending on the SENSOR SELECT switch position For channel 4 the measured TEC thermistor or RTD resistance is 12 145 kW or the measured AD590 current is 12 145 mA or the measured LM335 voltage is 12 145 mV depending on the SENSOR SELECT switch position TEC ALL SENsor Parameters Notes Examples DEVICE DEPENDENT The TEC ALL SENsor query is used to read back the SENSOR SELECT and THERM SELECT switch position value for all TEC channels Each value is a coded representation of the sensor type thermistor sensor current for each channel in ascending order None The response value of 1 thermistor at 100 mA 2 thermistor at 10 mA 3 LM335 sensor 4 AD590 sensor 5 RTD The sensor code for the selected TEC channel is displayed on the TEC display and bit 8 of the TEC event register is set whenever the back panel SENSOR SELECT switch position is changed The sensor selection must be made locally at the back panel SENSOR SELECT and THERM SELECT switches In local operation the setting of the SENSOR SELECT and THERM SELECT switches may be read by visually inspecting the back panel of the TEC channel in question If the response is 0 the sensor type is undetermined and a hardware error must exist TE
84. 6 Sensor Type Change While Output On Event 2 Voltage Limit Condition 512 Output Out of Tolerance Condition 4 N A 1024 Sensor Shorted While Output On Condition 8 High Temperature Limit Condition 2048 N A 16 TEC Interlock Changed Condition 4096 Software Error Condition 32 Booster Changed While Output On Event 8192 N A 64 Sensor Open While Output On Condition 16384 N A 128 Module Open While Output On Condition 32768 N A Notes The enabled TEC outoff bits for the selected TEC channel can be read by using the TEC ENABle OUTOFF query The value of the TEC outoff enable register for the selected TEC channel is stored in non volatile memory and is retained at power up The factory default setting for this register is H5E8 or 1512 decimal The High Temperature Limit Condition Sensor Open While Output On Condition and Sensor Type Change While Output On Event bits for the selected TEC channel will not be in effect and will not cause the selected TEC output to be shut off if the selected TEC channel is in ITE mode WARNING If the Output Out of Tolerance Change Event bit is set when the power is off the TEC output will not be able to be turned on until this bit is reset Examples TEC ENAB OUTOFF 9 action enables the TEC status outoff register so that a High Temperature Limit Condition or a TE Current Limit Condition will cause the TEC output to be turned off for the selected TEC channel Tec Enab Outof
85. A or the measured RTD resistance in kW depending on the position of the back panel Sensor Select switch If the Set switch is then pressed and R mode is selected in the TEC Mode section the display will show the thermistor resistance set point value in kW or the LM335 set point voltage in mV or the AD590 set point current in mA depending on the position of the SENSOR Select switch The ITE indicator becomes lit when the TEC drive current is displayed When the ITE switch is pressed the display will show the measured TEC drive current in Amps If the Set switch is then pressed and ITE mode is selected the TEC display will show the TEC drive current set point value in Amps The TEC Display Set indicator becomes lit when the display is showing the set point for the selected lit TEC value The Set Indicator goes off when the display is showing a measured TEC value TEC Parameter Section The Adjust TEC Indicator must be orange TEC adjust mode selected before adjusting the TEC Parameter values for the desired channel The following sections describe the function and form of each of the TEC parameters which may be adjusted from the unit s front panel Refer to Figure 2 9 on page 13 TEC GED PA RAMETE RMS ASER E LIMI Te LIM I E LIMT HI LIM P SELECT CONST CALPD CJ GAIN CI SAVE RECALL O Figure 2 18 LDC 3900 TEC Parameter Section TEC Parameter Select The Parame
86. A Users Guide Modular Laser Diode Controller LDC 3900 dih Lic nies 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 70011310 April 2010 Chapter 1 Chapter 2 Table of Contents a E a a El m El a a E E Table of ContentS oococcco i List of Figures o esdas iaaa da aA aa aa a td aA Aaa eed vii List of Tables 040 cee el aha a AA aa ee ix Safety and Warranty Information 000 0c eee eee xi Safety Information and the Manual 200cc eee eee eee xi General Safety Considerations n a anasan c eee eas xi Safety Symbols 0 000 cee tees xii Safety Marking Symbols 00 0000 cee eee xii WAITS ri aap ican ee oh eho coat te ee xiii EIMILAIONS scii ranns o aie a a Ea aa xiii Returning an Instrument 00 000 eee tee xiii Claims for Shipping Damage ssas uaaa aaaea xiv Comments Suggestions and Problems 000 een eeu XV Introduction and Specifications Product Overview 0 000 c cece eee 1 Available Options and Accessories 000 cece eee ene 2 Specifications 0 0 eee 3 Line Voltage Selection ooooccoccoccoo 3 Operation Installation reris Mees eee Mees Dee A de bee ae Oa 5 AC Power Considerations
87. AVE SET RECALL Figure 2 13 Laser Parameters The Laser Display is used to show Laser control measured and set point and parameter values It may also display errors which relate to Laser operation LASER CHANNEL mW yw et uo O ERROR O OPEN CIRCUIT O CURRENT LIMIT O INTLK ENBL OUTPUT SHORTED POWER LIMIT Figure 2 14 Laser Display 04_10 LDC 3900 Series 15 y OPERATION _ LDC 3900 Front Panel The LAS Channel indicators show which LAS channel may be adjusted LED lit and whose measurements are displayed They also blink if an error occurs ona LAS channel which is not presently selected for adjustment The Laser Error Indicators become lit when the corresponding Laser conditions occur For more information see Laser Error Indicators on page 30 The Output SHORTED light comes on whenever the selected Laser output is off The Modulation section is used for front panel connection of a DC to 500 kHz modulation signal which may be applied to a laser via a jumper to a laser current source module on the back panel of the LDC 3900 MODULATIO THROUGH TO REAR Figure 2 15 Modulation Automatic Laser Shutoff Conditions Laser Power Limit may be defeated via GPIB using the LAS ENAB OUTOFF command e Laser Interlock Laser Enable Switch State Changed see Laser module instruction manual e Laser Open Circuit While Output On TEC High Temperature Limit Condition may be defeated via GPIB
88. An lt nrf value gt which represents the selected channel s photodiode feedback power in mW Notes If the selected channel s CALMD CAL PD parameter is set to 0 the LAS MDP value will not be used In this case the measured MDP would be invalid and the MDI IPD set point would be used In local mode the photodetector power set point would be set by first pressing the LASER MODE P switch and then pressing the SET switch and then turning the Adjust Knob until the desired value appeared on the LASER display Examples Las Mdp 40 action The selected channel s LASER output is controlled so that the photodiode feedback power remains constant at 40 mW Laser MDP 200 action The selected channel s LASER output is controlled so that the photodiode feedback current remains constant at 200 mW LASer MDP COMMON DEVICE DEPENDENT FRONT PANEL The LASer MDP query returns the value of the selected channel s laser photodetector power measurement in mW Parameters None The response is an lt nrf value gt Notes The response is in mW The response is valid even when the unit is not in constant P mode This measurement is updated approximately once every 600 mSec In local mode the measured photodetector power would be read by pressing the LASER DISPLAY IPD PPD switch and visually reading the LASER display assuming P mode is selected and CALPD is not zero Examples Las Mode MDP Las Calmd 460 Las MDp response 100 0 means 100 m
89. C Laser Diode Mount Interconnect Cable 505 Calibrated 10 KQ Thermistor 510 Uncalibrated 10 kQ Thermistor 520 Uncalibrated AD590LH IC Temperature Sensor 530 Uncalibrated LM335AH IC Temperature Sensor 540 Blanking Plate to cover unused mainframe bay 3911 LDC 3900 Virtual Instrument for LabVIEW 393 1 Provided free of charge Contact ILX Lightwave Sales Representative 2 Virtual Instrument software requires National Instruments LabVIEW for Windows version 3 0 or higher Call for Virtual Instrument availability 2 LDC 3900 Series MIL Lightwave INTRODUCTION AND SPECIFICATIONS Product Overview Specifications The general specifications for the LDC 3900 are found on page 3 The specifications for each module are found in the instruction manual for that module Table 1 3 GPIB Specifications Meets ANSI IEEE Std 488 1 1987 and Std 488 2 2 1987 Table 1 4 General Specifications GENERAL Size 5 625 x 16 75 x 13 625 145mm x 426mm x 346mm Weight Mainframe 27 5 lbs 12 5 kg Module each typical 2 3 lbs 1 05 kg Power Requirements 100 V 10 120 V 10 220 V 10 230 240 V 10 50 60 Hz Temperature 0 to 40 C operating 40 to 70 C storage Humidity lt 95 relative humidity non condensing 1 The current source modules contain circuits that will turn off their outputs if a transient is detected A CAUTION There are no user serviceable parts in the
90. C ALL Sensor response 1 1 1 2 means that for channels 1 3 the TEC SENSOR SELECT switch is in the THERM position and the THERM SELECT switch is in the 100 mA position For channel 4 the TEC SENSOR SELECT switch is in the THERM position and the THERM SELECT switch is in the 10 mA position Tec All SEN response 3 INF 3 3 means that for channels 1 3 and 4 the TEC s LM335 sensor is selected by the back panel SENSOR SELECT switch The position of the THERM SELECT switch in this case is not relevant Channel 2 is either has no TEC module or is out of service LDC 3900 Series 139 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL T DEVICE DEPENDENT The TEC ALL T command sets the TECs constant temperature set point for all channels in ascending order Parameters Four lt nrf value gt s which represents the TEC temperature in C for the each channel in ascending order Notes A given TEC s temperature will be controlled to the corresponding set point only when that channel s TEC is operated in T mode If an entered value is greater than 199 9 an error E222 will be generated and the temperature set point parameter for the given channel will not be changed If an entered value is less than 99 9 an error E223 will be generated and the temperature set point parameter for the given channel will not be changed Examples Tec All T 20 20 20 20 action sets the temperature set points to 20 0 C on all cha
91. C ALL V response 3 423 3 552 3 31 3 4 means the measured TEC load voltage is 3 423 volts for channel 1 3 552 volts for channel 2 3 310 volts for channel 3 and 3 400 volts for channel 4 All channels contain 39034 modules 140 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC CAL COMMON DEVICE DEPENDENT FRONT PANEL The TEC CAL command path is used to get to the selected TEC channel s TEC calibration commands In local operation the TEC calibration mode is reached by pressing the GPIB LOCAL and TEC DISPLAY R or ITE switches at the same time When sensor calibration mode is selected with the R switch the position of the SENSOR SELECT switch will be displayed on the TEC display for two seconds The following commands may be reached directly from the TEC CAL command path TEC CAL ITE TEC CAL ITE TEC CAL SENsor TEC CAL SENsor TEC CAL V TEC CAL V TEC CAL ITE COMMON DEVICE DEPENDENT FRONT PANEL The TEC CAL ITE command is used to enter the TEC s current set point measurement and limit calibration mode for the selected TEC channel Parameters None Notes This is a service related command When this command is issued the front panel becomes disabled and the appropriate adjustments are made to the operating modes This mode should not be entered unless the user has the proper measurement equipment in place See the Calibration section of the TEC module ins
92. C ENAB EVE 1 Sets the present channel s enable register for TEC events TEC ENAB EVE NONE Returns the value of the present channel s TEC event enable register TEC ENAB OUTOFF 1 Sets the present channel s enable register for TEC conditions which turn the TEC output off TEC ENAB OUTOFF NONE Returns the value of the present channel s TEC outoff 2 enable register TEC EVENT NONE Returns the value of the present channel s TEC event register TEC GAIN 1 Used to set the present channel s TEC control loop gain parameter TEC GAIN NONE Used to return the present channel s TEC control loop gain parameter TEC INC NONE Used with TEC STEP command to increment the present channel s TEC set point value by one step TEC ITE 1 Used to set the present channel s TEC current ITE set point TEC ITE NONE Returns the present channel s measured TEC current ITE value measured about every 600 msec TEC LIM ITE 1 Used to set the present channel s TEC constant current source limit value TEC LIM ITE NONE Used to return the present channel s constant current source limit value TEC LIM THI 1 Used to set the present channel s TEC upper temperature limit value TEC LIM THI NONE Returns the present channel s TEC upper temperature limit value TEC MODE NONE Returns the present channel s mode ITE TEC current R resistance reference or T temperature TEC MODE ITE NONE Sets the present TEC channel to constant TEC current mode TEC MODE R NO
93. C for the selected TEC channel MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC LIMit THI COMM DEVICE DEPENDENT FRONT PANEL The TEC LIMit THI query returns the value of the TEC load s high temperature limit for the selected TEC channel Parameters None The response is an lt nrf value gt Notes The temperature limit is valid for R and T modes of TEC output operation for the selected TEC channel In local operation the THI limit value is read by pressing the TEC PARAMETER SELECT switch until the LIM THI indicator is lit and reading the value on the TEC display If the high temperature limit is set too low the TEC output may not be able to be turned on if the high temperature condition is also used to turn the TEC output off see TEC ENABle OUTOFF Examples TEC LIM Thi response 30 5 means the TEC load s high temperature limit is 30 5 C for the selected TEC channel Tec Limit THI response 184 7 means the TEC load s high temperature limit is 184 7 C for the selected TEC channel TEC MODE COMMON DEVICE DEPENDENT FRONT PANEL The TEC MODE query returns the present TEC control mode for the selected TEC channel Parameters None The response is a character response Notes The TEC mode also identifies the type of parameter which is controlled for a given TEC channel The TEC output is kept at the corresponding set point In local operation the mode is of operation is
94. C output current limit is 4 000 amps for the selected TEC channel TEC LIMit THI Co DEVICE DEPENDENT FRONT PANEL The TEC LIMit THI command sets the TEC high temperature limit value for the selected TEC channel Parameters An lt nrf value gt which represents the upper bound of the TEC load temperature in C for the selected TEC channel Notes The THI limit value must be in the range 0 199 9 C If an entered value is greater than 199 9 an error E222 will be generated and the LIM THI parameter will not be changed If an entered value is less than 0 an error E223 will be generated and the LIM THI parameter will not be changed If the new limit value is lower than the present temperature set point the temperature set point will be forced down to the value of the THI limit and an E434 error will be generated In local operation the THI limit is set by selecting the LIM THI parameter pressing the PARAMETER SET switch adjusting the Adjust Knob until the desired value appears on the TEC display and then releasing the SET switch The default setting of the TEC outoff enable register for the selected TEC channel forces the selected TEC output to be shut off if the high temperature limit is reached See the TEC ENABle OUTOFF command Examples TEC LIM THI 100 action sets the TEC load temperature limit to 100 0 C for the selected TEC LDC 3900 Series channel Tec Lim thi 30 3 action sets the TEC load temperature limit to 30 3
95. Commands LASer ALL MDP Parameters Notes Examples DEVICE DEPENDENT The LASer ALL MDP query returns the value for each channel of the laser monitor photodetector power measurement in mW None The response is four lt nrf value gt s separated by commas which represent the measurements from each channel in ascending order The response is in mW A response is valid even when the channel is not in constant P mode as long as the module type is correct some combination modules do not support constant MDI MDP mode This measurement is updated approximately once every 600 mSec per channel Las ALL Mode MDP Las ALL Calmd 460 Las ALL MDp response 100 0 99 5 9 7 0 0 means 100 mW of photodetector power from channel 1 99 9 mW from channel 2 9 7 mW from channel 3 and 0 0 mW from channel 4 Monitor diode feedback is controlling the laser current output on channels 1 3 Channel 4 s LAS output is probably off LAS ALL MODE IHBW LAS All MDP response 20 0 10 5 2 8 3 7 means 20 0 mW of photodetector power on channel 1 10 5 mW on channel 2 2 8 mW on channel 3 and 3 7 mW on channel 4 However photodiode monitor power is not controlling the laser output current on any of the channels due to the IHBW mode LASer ALL MODE Parameters Notes Examples DEVICE DEPENDENT The LASer ALL MODE query returns the laser control mode for all four channels None The response is character data for each channe
96. Controllers have a special mode for operating at a constant monitor photodiode current when the CAL PD parameter value is set to zero This constant lpp mode is useful for driving a laser when the monitor photodiode s responsivity is not known but a desired constant light output can be determined to produce a constant monitor photodiode current The constant Ipp mode is also used for monitor feedback calibration Constant lygw is a high bandwidth constant current mode This mode allows the laser drive current output to be modulated up to 500 kHz via the front and or back panel MODULATION connectors LASER MODE SELECT Figure 2 20 LDC 3900 Laser Mode Section 04_10 LDC 3900 Series 25 LDC 3900 Series OPERATION _ LDC 3900 Front Panel Laser Mode Select The Laser Mode Select switch is used to select one of the three available Laser operating modes When a mode is selected the corresponding LED becomes lit If the Laser Mode Select switch is pressed repeatedly the modes are cycled through in the order I P Iypy and back to I and so on with the appropriate Mode Indicator being lit Laser Mode Indicators The Indicator becomes lit when the unit is in the constant current control mode When constant mode is selected the Laser output is controlled to the constant set point value The P Indicator becomes lit when the unit is in constant optical power control mode When co
97. DP LASer TOLerance 04 10 LDC 3900 Series 87 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL DEVICE DEPENDENT The LASer ALL command path is used to get to the global LAS commands These commands are sent to all channels of the LDC 3900 regardless of the selected LAS channel These commands expect that there are LAS or combination LAS TEC modules present in all four channel bays If a LAS ALL command is issued and one or more channels contain neither LAS or LAS TEC combination modules an E533 error will be generated The following command paths may be reached from the LASer command path LASer ALL LIM LASer ALL MODE LASer ALL ONLY The following commands may be reached directly from the LASer ALL command path LASer ALL CALMD LASer ALL CALMD LASer ALL LDI LASer ALL LDI LASer ALL LDV LASer ALL MODE LASer ALL OUTput LASer ALL OUT put LASer ALL CALMD Parameters Notes Examples 88 LDC 3900 Series DEVICE DEPENDENT The LASer ALL CALMD command sets the laser s photodiode feedback responsivity the CAL PD parameter on all LAS channels Four lt nrf value gt s in microamps milliwatt The parameters are in ascending order one for each channel If a parameter is set to 0 the corresponding LAS channel will operate in a constant IPD mode when Constant P mode is selected The parameters should be set to 0 for IPD calibration modes Otherwise the value of this parameter is
98. E ITE CONST CONST ITE ITE CONST GAIN SEN R DEC GAIN ITE ITE OUT SEN R DIS ITE ITE 3R y SET DIS ITE THI T V SET EVE MODE THI T GAIN OUT T GAIN OUT PARAM INC IR ITE R ITE SEN MODE T OUT iT OUT N R R SEN STB STEP STEP aE T TOL TOL v Vv oe AA ENAB COMMAND REFERENCE LDC 3900 Device Dependent Commands LIM il 1 MDP MDP COND COND EVE EVE OUTOFF OUTOFF Figure 4 1 Command Path Tree Structure MODE ONLY HBW OUT LBW MDP LIM MODE ITE ITE ITE CR A THI T T THI root MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LDC 3900 Device Command Reference The following pages contain a reference for the device dependent commands of the LDC 3900 Modular Laser Diode Controller This reference contains useful information for both local and remote operation of the LDC 3900 References to the front panel labels are capitalized in the following reference pages as is done throughout this manual Therefore a reference to the Laser display is meant to signify the actual 5 digit display labeled Laser on the front panel of the LDC 3900 Modular Laser Diode Controller while a reference to the Laser Display refers to the same labeled switch area of the LDC 3900 In some references parentheses are used to signify the labeled a
99. EVICE DEPENDENT FRONT PANEL The TEC CHAN query returns the channel number of the TEC module which has been selected for display and adjustment Parameters None The response is the channel number of the selected TEC module Notes If no TEC channels exist the response will be 0 In local mode the user would read the TEC channel selection visually The selected channel would have the corresponding orange TEC LED lit in the ADJUST section Examples TEC CHAN response 1 means the TEC module in channel 1 is selected for adjustment and display TEc Chan response 2 means the TEC module in channel 2 is selected for adjustment and display 144 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC COND DEVICE DEPENDENT The TEC COND query returns the value of the status condition register of the TEC operations for the selected TEC channel Parameters None The response is the sum of the following 1 TE Current Limit 256 N A 2 Voltage Limit Error 512 Output Out of Tolerance 4 N A 1024 Output On 8 High Temperature Limit 2048 Ready for Calibration Data 16 TEC Interlock Enable 4096 Calculation Error 32 Booster Enable 8192 Internal Communication Error with TEC Board 64 Sensor Open 16384 Software Error 128 TE Module Open 32768 TEC EEPROM Checksum Error Notes The enabled TEC conditions can be set by using the TEC ENABle COND command for the selected
100. For example a step of 1 means 0 1 C 0 001 kW THERM 0 01 mA AD590 0 1 mV LM335 0 01 W RTD or 1 mA ITE TEC Mode T TEC Step response 2 means the selected TEC s step size is 0 2 C This value is in tenths of a degree C since Const T mode is in effect Tec MODE R TEC STEP response 40 means the selected TEC s step size is 40 W assuming the SENSOR SELECT switch is in the THERM position This value is in W since Const R mode is in effect and a thermistor sensor is selected Tec MODE ITE Tec STEP response 20 means the step size is 20 mA This value is in mA since Const ITE mode is in effect TEC T Parameters Notes Examples 168 LDC 3900 Series DEVICE DEPENDENT FRONT PANEL The TEC T command sets the TEC s constant temperature set point for the selected TEC channel An lt nrf value gt which represents the TEC temperature in C for the selected TEC channel The selected TEC s temperature will be controlled to this set point only when the TEC is operated in T mode In local operation the R set point is entered by selecting ADJUST TEC and R modes pressing the TEC DISPLAY SET switch adjusting the Adjust Knob within 3 seconds and then releasing the SET switch when the desired value is shown on the TEC display Tec T 20 action sets the selected TEC s temperature set point to 20 0 C TEC MODE T TEC T 25 3 action sets the selected TEC s temperature set point to 25 3 C The
101. MM DEVICE DEPENDENT The TEC ALL CONST command sets the TEC s Steinhart Hart equation constants the same for all TEC channels All channels are set the same Parameters Three lt nrf values gt for the three Steinhart Hart equation constants or the two linear calibration constants for linear IC sensors for linear sensors C3 is not used may be set to 0 The range of values is 9 999 to 9 999 for all three constants However for a thermistor sensor these values are scaled by the appropriate exponential value for the Steinhart Hart equation see Appendix A Notes All three parameters are required with version 3 1 firmware and above When the LM335 AD590 or RTD sensors are selected via the SENSOR SELECT switch only C1 and C2 are used C3 is ignored If an entered value is greater than 9 999 an error E222 will be generated and the CONST parameter for the given channel will not be changed If an entered value is less than 9 999 an error E223 will be generated and the CONST parameter for the given channel will not be changed Examples Tec All CONST 1 2 33 0 5 action sets C1 to 1 000 C2 to 2 330 and C3 to 0 500 on all channels 1 4 Tec ALL CONST 1 4 1 015 0 action sets C1 to 1 400 C2 to 1 015 C3 to 0 0 for use with two point calibration of AD590 LM335 or RTD sensors C3 is not used in the conversion of reference to temperature with linear sensors TEC ALL CONST DEVICE DEPENDENT The TEC ALL CONST query retu
102. NC action The mode is set for constant temperature and the set temperature is incremented by 0 2 C for the selected TEC channel TEC Mode r Tec STEP 20 Tec inc action The mode is set for constant resistance and the set point is incremented by 20 0 02 K W for the selected TEC channel assuming that the SENSOR SELECT switch is in the THERM position TEC ITE C DEVICE DEPENDENT FRONT PANEL The TEC ITE command sets the TEC control current set point for the selected TEC channel It is also used to enter the TEC current calibration value Parameters An lt nrf value gt which represents the ITE set point current for the selected TEC channel in Amps In ITE current calibration mode the lt nrf value gt represents the measured current value in Amps Notes This set point is used by the TEC s constant ITE mode only In local operation the ITE set point is entered by selecting ADJUST TEC and ITE modes pressing the TEC DISPLAY SET switch adjusting the Adjust Knob within 3 seconds and then releasing the SET switch when the desired value is shown on the TEC display Examples TEC ITE 1 action sets the TEC output current set point to 1 000 Amps for the selected TEC channel TEC MODE ITE Tec lte 3 5 action sets the TEC output current set point to 3 500 Amps for the selected TEC channel and the output is controlled to that value LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ITE
103. NE Sets the present TEC channel to constant thermistor resistance linear sensor reference mode LDC 3900 Series 81 COMMAND REFERENCE _ LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION TEC MODE T NONE Sets the present TEC channel to constant temperature mode TEC ONLY OUT 1 Sets the present TEC channel s TEC output only on or off Useful with combination modules TEC OUT 1 Same action as setting the present TEC channel s OUTPUT switch on off TEC OUT NONE Returns the present TEC channel s OUTPUT switch status TEC R 1 Sets the present channel s constant R resistance reference set point TEC R NONE Returns the present TEC channel s measured R resistance reference value measured about every 600 msec TEC SEN NONE Returns the position of the SENSOR SELECT switch of the present TEC channel TEC SET ITE NONE Returns the present channel s constant ITE TEC current set point TEC SET R NONE Returns the present channel s constant R resistance reference set point TEC SET T NONE Returns the present channel s constant T temperature set point TEC STB NONE Returns the present channel s status summaries for conditions and events TEC STEP 1 Used to set the present channel s TEC step value for use with DEC or INC commands Defaults to a step of 1
104. NST parameter will not be changed If an entered value is less than 50 000 an error E223 will be generated and the CONST parameter will not be changed In local operation the constants are entered individually by selecting CONST in the PARAMETER section of the front panel The constant number i e 1 2 or 3 is shown in the LASER display Then with the SET switch pressed and held in the parameter value may be adjusted by turning the Adjust Knob When the SET switch is released the value is stored in nonvolatile memory Examples Tec CONST 1 2 33 0 5 action sets C1 to 1 000 C2 to 2 330 and C3 to 0 500 Tec CONST 1 4 1 015 0 action sets C1 to 1 400 C2 to 1 015 and C3 to 0 000 for two point calibration of AD590 LM335 or RTD sensors C3 is not used 04_10 LDC 3900 Series 145 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC CONST COMM DEVICE DEPENDENT FRONT PANEL The TEC CONST query returns the value of the TEC s Steinhart Hart constants or the linear sensor conversion constants for the selected TEC channel Parameters None The response data represent the values of C1 C2 and C3 respectively Notes When the LM335 AD590 or RTD sensors are selected via the SENSOR SELECT switch only C1 and C2 are used Therefore C3 values may be ignored for these cases In local operation the constants may be read by selecting LED lit the desired parameter in the PARAMETER section of the front panel and visua
105. PANEL The TEC DISplay R query returns the status of the TEC DISPLAY R switch Parameters None The response is an lt nrf value gt Notes The response will be the status of the TEC DIS R switch 1 on O off In local operation the status of the TEC R display switch is determined by visually inspecting the LED indicator on the TEC DISPLAY R and SET switches The R measurement will be displayed if the SET indicator is off and the R indicator is on lit ON Examples TEC Dis R response 0 means that the TEC DIS R switch is not active Therefore TEC sensor resistance or AD590 current or LM335 voltage is not displayed Tec dis R response 1 means that the TEC DIS R switch is active Therefore TEC sensor resistance or AD590 current or LM335 voltage may be displayed TEC DISplay SET COMM DEVICE DEPENDENT FRONT PANEL The TEC DISplay SET command sets the TEC display to show the currently selected mode s set point value for the selected TEC channel Parameters None Notes Using this command has the same effect as physically holding the TEC DISPLAY SET switch down in Examples Tec Dis Set action enables the TEC display for the set point of the selected mode ITE R or T TEC Dis Set action enables the TEC display for the set point of the selected mode ITE R or T TEC DISplay SET Co DEVICE DEPENDENT FRONT PANEL The TEC DISplay SET query returns the status of the TEC display set point switch Par
106. S NONE Returns the LAS display value LAS DIS LDI NONE Turn on off LAS display to show output current LAS DIS LDI NONE Returns on off status of DIS switch LAS DIS LDV NONE Turn on off LAS display to show output voltage LAS DIS LDV NONE Returns on off status of DIS V switch LAS DIS MDI NONE Returns on off status of DIS IPD switch LAS DIS MDP NONE Turns on off display to show PD monitor power LAS DIS MDP NONE Returns on off status of DIS PPD switch LAS DIS PARAM NONE Enables the LAS display to show parameter values LAS DIS SET NONE Same action as setting LAS DIS SET switch LAS DIS SET NONE Returns on off status of LAS DIS SET switch LAS ENAB COND 1 Sets present channel s enable register for LAS conditions LAS ENAB COND NONE Returns the value of the present LAS conditions enable register LAS ENAB EVE 1 Sets the present channel s enable register for LAS events LAS ENAB EVE NONE Returns the value of the present LAS event enable register LAS ENAB OUTOFF 1 Sets the present enable register for LAS conditions which turn the LAS output off LAS ENAB OUTOFF NONE Returns the value of the present LAS outoff enable register LAS EVENT NONE Returns the value of the present LAS event register LAS INC 0 1 or2 Used with LAS STEP command to increment the present LAS set point value by one or more steps LAS LDI 1 Used to set the present channel s LAS constant current source set point value LAS LDI NONE Used to return
107. Softwar 9 LASER EEPROM Checksun tus SERVI REQUE Irena SENERATI TEC Condition Status ss i TEC CONI Voka Brbebpeee EELEE 3 1 Master Statu E rice Request Ena a SRE Out QUEUE SR Output NOT EMPTY e ee abia Ready for Calibration PA A Camel eb bPt odon TEC Condition Status Enabl TEC ENABI Ni TEC ENABI TEC Event Status Enabl TEC ENABle EVEnt TES ENABI Figure 3 11 LDC 3900 Status Reporting Schematic Diagram 04 10 LDC 3900 Series 65 REMOTE OPERATION _ Status Reporting Operation Complete Definition Note that bit O of the Standard Event Status Register contains the status of the Operation Complete flag see OPC on page 52 Enabling this bit via the ESE command allows the user to update bits of the status byte Then if the SRE mask has bit 5 set and the user issues an OPC command an SRQ will be issued upon completion of the currently processed commands This may be used to initiate service request routines which depend on the completion of all previous commands Note The definition of operation complete has been changed for firmware v3 5 and above No longer is operation complete dependent on new measurements or tolerance status Operation Complete on the LDC 3900 Modular Laser Diode Controller is defined as The Laser controllers which are updating the Laser current source modules hardware are all idle The TEC controllers which are updating the
108. TEC ALL TEC CAL TEC DISplay TEC ENABle TEC LIMit TEC MODE TEC ONLY TEC SET The following commands may be reached directly from the TEC command path TEC COND TEC INC TEC STEP TEC CONST TEC ITE TEC STEP TEC CONST TEC ITE TEC T TEC DEC TEC MODE TEC T LDC 3900 Series 129 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC DISplay TEC OUT put TEC TOL TEC DISplay TEC OUT put TEC TOL TEC EVEnt TEC R TEC V TEC GAIN TEC R TEC V TEC GAIN TEC SENsor TEC ALL COMMON DEVICE DEPENDENT FRONT PANEL The TEC ALL command path is used to get to the global TEC commands These commands are sent to all channels of the LDC 3900 regardless of the selected TEC channel These commands expect that there are TEC or combination LAS TEC modules present in all four channel bays If a TEC ALL command is issued and one or more channels contain neither TEC or LAS TEC combination modules an E433 error will be generated The following command paths may be reached from the LASer command path TEC ALL LIM TEC ALL MODE TEC ALL ONLY The following commands may be reached directly from the TEC ALL command path TEC ALL CONST TEC ALL CONST TEC ALL GAIN TEC ALL GAIN TEC ALL ITE TEC ALL ITE TEC ALL MODE TEC ALL OUT TEC ALL OUT TEC ALL R TEC ALL R TEC ALL T TEC ALL T TEC ALL V 130 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL CONST CO
109. TEC channel The TEC condition status is constantly changing while the event status is only cleared when the event status is read or the CLS command is issued Examples TEC COND response 513 means that the Output Out of Tolerance and TE Current Limit TEC conditions currently exist for the selected TEC channel Radix Hex TEC Cond response H82 means that the TE Module Open and Voltage Limit TEC conditions currently exist for the selected TEC channel TEC CONST Co DEVICE DEPENDENT FRONT PANEL The TEC CONST command sets the TEC s Steinhart Hart equation constants for the selected TEC channel Parameters Three lt nrf value gt s for the three Steinhart Hart equation constants or the two linear calibration constants for linear IC sensors and a third unused value The range of values is 9 999 to 9 999 for all three constants However for a thermistor sensor these values are scaled by the appropriate exponential value for the Steinhart Hart equation see Appendix A Notes When the LM335 AD590 or RTD sensors are selected via the SENSOR SELECT switch only C1 and C2 are used C3 is ignored Versions of the LDC 3900 prior to v3 1 allowed parameters to be omitted This is no longer permitted Also with v3 1 and higher user entered parameters outside of the valid range for that parameter will be ignored and an error code will be generated If an entered value is greater than 50 000 an error E222 will be generated and the CO
110. TEC modules hardware are all idle No calibration routines are running Note Care must be taken when using the OPC OPC and WAI commands with LAS OUT ON commands If the GPIB times out while waiting for a response which indicates completion either set the GPIB timeout longer or use SRQ generated interrupts in the program See your GPIB manual for timeout configuration or SRQ programming setup The OPC OPC and WAI commands should not be used inside a calibration routine except to detect the completion exiting of calibration Notice that Operation Complete criteria will hold the OPC flag false throughout calibration If the program waits until the OPC flag is true before entering a calibration value it will wait forever Command Timing and Completion This section describes for each device dependent command whether that command is performed in an overlapped or sequential manner In other words it states whether the next command may begin while this command is being executed or if the next command must wait until this command is completed before its execution begins The conditions for setting the operation complete flag are given in the Operation Complete Definition on page 66 All LDC 3900 device dependent commands are executed in a sequential manner except for the LAS OUT ON and other commands which may turn a laser output on The operation complete flag is set after the conditions outlined in the Operation Complete D
111. TEC output off see TEC ENABle OUTOFF Examples TEC ALL LIM Thi response 30 5 50 0 50 0 50 0 means the TEC load s high temperature limit is 30 5 C for the channel 1 and 50 0 C for channels 2 4 Tec All Limit THI response 184 7 100 0 50 0 33 4 means the TEC load s high temperature limit is 184 7 C for channel 1 100 0 C for channel 2 50 0 C for channel 3 33 4 C for channel 4 TEC ALL MODE COMMON DEVICE DEPENDENT The TEC ALL MODE query returns the present TEC control mode for all channels in ascending order Parameters None The response is character data for each channel separated by commas Notes The TEC mode also identifies the type of parameter which is controlled for a given TEC channel The TEC output is kept at the corresponding set point Examples Tec ALL MODE response Ite Ite te lte means that constant ITE current mode is in effect for the TEC output for all channels TEC All Mode response R Ite lte T means that constant R resistance reference mode is in effect for the TEC output for channel 1 Ite mode is in effect for channels 2 and 3 and T constant temperature mode is in effect for channel 4 TEC ALL MODE DEVICE DEPENDENT The TEC ALL MODE command path is used to get to the global TEC mode selection commands The following commands may be reached directly from the TEC ALL MODE command path TEC ALL MODE ITE TEC ALL MODE R TEC ALL MODE T 04_10 LDC 3900 Ser
112. ULE OPEN indicator LED flashes at 1 Hz not in effect when booster source is used MIL Lightwave OPERATION LDC 3900 Front Panel Laser Mode Section The Laser Mode Select switch determines which Laser mode is used to control the output of a Laser current source module One of the following may be selected at one time constant current I constant optical light power P or constant current with a high bandwidth output lygy mode The Adjust LAS indicator must be orange before changing the values of the Laser Mode functions for that channel Refer to Figure 2 11 on page 15 for the discussion of the Laser Mode section features Constant mode is the normal mode for driving lasers This mode uses a low pass filter on the laser drive current output to significantly reduce noise In this mode a modulation input of up to 10 kHz may be used via the front panel MOD External connector Constant P mode is also a low bandwidth mode It is used when it is desired to control the optical power of the laser via a monitor photodiode feedback arrangement When P mode is selected the unit will be in either lpp or Ppp modes depending on the setting of the CAL PD monitor photodiode responsivity parameter If the CAL PD value is non zero the unit will operate in constant Ppp monitor photodiode power light power mode For more information on the CAL PD parameter see CAL PD on page 29 The LDC 3900 Modular Laser Diode
113. Used to enter the present channel s Steinhart Hart constants for R T conversion Also used to enter constants for AD590 LM335 and RTD TEC CONST NONE Used to read back the present channel s Steinhart Hart constants for R T conversion Also used to read back constants for AD590 LM335 and RTD TEC DEC none Used with STEP command to decrement the present channel s set point value by one step TEC DIS 1 Turns the TEC display on or off TEC DIS NONE Returns the TEC display value TEC DIS ITE NONE Turn on off TEC display to show TEC current TEC DIS ITE NONE Returns on off status of DIS ITE switch 80 LDC 3900 Series Im IL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION TEC DIS R NONE Turn on off display to show resistance or reference value TEC DIS R NONE Returns on off status of DIS R switch TEC DIS SET NONE Same action as setting TEC DIS SET switch TEC DIS SET NONE Returns on off status of TEC DIS SET switch TEC DIS T NONE Turns on off TEC display to show temperature TEC DIS T NONE Returns on off status of DIS T switch TEC ENAB COND 1 Sets the present channel s enable register for TEC conditions TEC ENAB COND NONE Returns the value of the present channel s TEC conditions enable register TE
114. W of photodetector power from the selected LAS channel This feedback is controlling the laser selected channel s current output LAS MODE IHBW LAS MDP response 20 0 means 20 mW of photodetector power from the selected LAS channel but photodiode monitor power is not controlling the selected channel s laser output current 04_10 LDC 3900 Series 119 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer MODE COMMON DEVICE DEPENDENT FRONT PANEL The LASer MODE query returns the present LAS channel s selected laser control mode Parameters None The response is character data Notes IHBW mode is the same as mode low bandwidth except that the output low bandpass filter is disabled in IHBW mode In local mode the LASER control mode is indicated by the LED in the LASER MODE area of the front panel If the P mode LED is lit the mode is IPD when the CAL PD value is zero and the mode is PPD when the CAL PD value is non zero Examples LAS MODE response Ilbw means that constant current mode is in effect for the selected channel s laser output Las Mode response MDP means that constant P power mode is in effect for the selected channel s laser output and CALMD gt 0 Las Mode response MDI means that constant P power mode is in effect for the selected channel s laser output and CALMD 0 Laser MODE response Ihbw means that constant IHBW current high bandwidth mode is in effect
115. ach of the registers which may be accessed by a command or query has the appropriate command or query written above or below the register representation For example the Laser Condition Register may be queried via the LASer COND query as shown by its register heading in Figure 3 11 on page 65 The condition or event registers are logically ANDed with their respective enable registers These bits are then logically ORed to form a summary message in the status byte for that particular type of register The Laser and TEC condition and event registers for each channel are logically ORed to form the complete summary message in the status byte For example if a LAS COND is enabled on LAS CHAN 1 and that condition occurs on channel 1 bit 3 of the Status Byte Register would be set Likewise if a LAS COND is enabled on LAS CHAN 2 and that condition occurs on channel s bit 3 of the Status Byte Register would also be set Therefore if bit 3 of the Status Byte Register is set and there is more than one Laser channel with enabled conditions for status reporting the user must poll each of the enabled LAS COND registers to determine the source of the summary message in bit 3 of the Status Byte Register Event and Condition Registers The Event Registers are used to report events which occur during the operation of the LDC 3900 Modular Laser Diode Controller Events differ from conditions in that events signal an occurrence once and are not rese
116. ack mount accessory kits contain detailed mounting instructions Refer to Table 1 2 on page 2 for applicable rack mount accessory part numbers Power Up Sequence With the LDC 3900 Modular Laser Diode Controller connected to an AC power source pressing the top side of the Power Rocker switch will supply power to the instrument and start the power up sequence Note All LDC 3900 modules that contain a laser current source have remote interlock capability This allows you to connect the interlock circuit to an external switch for safety If the interlock is removed the laser current output is disabled Refer to the laser module manual for details about the interlock function The LDC 3900 is also equipped with a laser enable key switch This ensures that the laser current can be turned on only if the key is inserted and in the On position During the power up sequence a lamp test is conducted all indicators illuminate for 3 seconds and the 7 segment displays indicate 8 Next all of the LED s are turned off for about two seconds After this the firmware version number is displayed on the Laser display for about two seconds With v3 1 and higher the TEC display shows the firmware checksum value during the same time that the firmware version is displayed During this two second interval a self test is performed to ensure that the unit s hardware and software are communicating If the unit cannot successfully complete this test an error
117. ameters None The response value of 0 set point disabled measured value may be displayed 1 set point enabled Notes The set point display will not time out when remote operation is used It will be continuously displayed In local operation the status of the TEC DISPLAY SET switch is determined by visually inspecting the LED indicator on the switch lit ON Examples TEC DISPL SET response 0 means the set point value is disabled for the TEC display Tec Dis Set response 1 means the set point value is enabled for the TEC display 04_10 LDC 3900 Series 149 150 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC DISplay T DEVICE DEPENDENT FRONT PANEL The TEC DISplay T command enables the TEC display to show the TEC load temperature measurement for the selected TEC channel Parameters None Notes The actual TEC T display is turned off automatically when another TEC display selection is enabled In local operation the TEC T display is enabled by pressing the T switch in the TEC DISPLAY area of the front panel Examples Tec Dis T action enables the TEC display for the TEC load s measured temperature TEC DIS T action enables the TEC display for the TEC load s measured temperature TEC DISplay T COMMON DEVICE DEPENDENT FRONT PANEL The TEC DISplay T query returns the status of the TEC DISPLAY T switch Parameters None The response is an lt nrf value gt Notes The response
118. annot be divided Rectangles contain non terminal syntactic elements These represent elements which are expandable to a diagram of terminal syntactic elements However they are presented as a unit for clarity or emphasis gt Lines and arrows indicate correct paths through the syntax diagram A reverse line around an element indicates that the element may be repeated indefinitely A forward arrow around an element indicates that the element may be omitted White Space White space is defined by the syntactic diagram shown in Figure 3 1 on page 40 where lt white space character gt is defined as a single ASCIl encoded byte in the range 00 09 0B 20 0 9 11 32 decimal This range includes the ASCII control characters carriage return and the space but excludes the new line character In most practical programming situations the space character space bar would be used as white space White space is generally used for separating other 04_10 LDC 3900 Series 39 REMOTE OPERATION ANSI IEEE 488 2 Definitions syntactic elements White space is processed by the LDC 3900 Modular Laser Diode Controller without interpretation lt white space character gt Figure 3 1 White Space Syntactic Diagram Power on Conditions At power on the LDC 3900 Modular Laser Diode Controller complies with the ANSI IEEE Std 488 2 1987 requirements It will initialize the setup parameters to be the same as when the power was last shut down
119. ar with the command syntax and structure you may take advantage of some programming shortcuts which are available Due to the tree walking capabilities of the LDC 3900 software the user may elect to write command strings without constantly repeating the entire command path for each command Path Specification The first command in the string must have its entire path entered But once a path level is reached other commands which are at the same level or higher level may then be entered without repeating the path To accomplish this the semicolon must be used to separate the commands in the string as usual However the command following the semicolon need not specify its full path if the same path which was previously written out could be used for the new command For example the following legal command string could be used to 1 set the LDC 3900 TEC display to the measured temperature and 2 set the TEC display for the temperature set point value TEC DIS T Ser The path TEC DIS is remembered by the LDC 3900 software in this case If the Set command were not found at this level the software would walk back to the TEC level and search for a TEC Set command If it is not found there it will search at the next higher level and so on until it finds the command or not If the command is not found an error message will be generated The following is an example of command tree walking where 1 the Laser
120. arameters An lt nrf value gt which represents the TEC voltage for the selected TEC channel Notes If the TEC module 39034 is not in voltage calibration mode when this command is issued an error E419 will be generated Examples Tec V 6 37 action sets the selected TEC s voltage calibration set point to 6 370 volts TEC V COMMON DEVICE DEPENDENT The TEC V query returns the value of the TEC voltage measurement for the selected TEC channel 39034 only Parameters None The response is an lt nrf value gt Notes The measured TEC voltage is valid in all modes of TEC operation This measurement is updated approximately once every 600 msec Examples TEC V response 2 423 means the measured TEC voltage is 2 423 volts for the selected TEC channel 39034 only 04_10 LDC 3900 Series 171 172 COMMAND REFERENCE LDC 3900 Device Dependent Commands TERM Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT The TERM command allows the programmer to select the message terminator type for GPIB messages lt CR gt carriage return lt CR gt lt NL gt new line lt CR gt lt END gt EOI lt CR gt lt NL gt lt END gt lt NL gt lt END gt lt NL gt and lt END gt are allowed NOTE with LDC 3900 v3 2 and higher EOI END is required Thus only parameters of 0 2 4 or 6 will work properly Setting the LDC 3900 with parameter 0 default or 4 IEEE488 2 standard is recommended A
121. arameters None The response will be either 0 off or 1 on Notes In local operation the status of the PPD switch is determined by visually inspecting the PPD indicator in the LASER DISPLAY area of the front panel The status of the PPD switch is on if its indicator is lit and the SET indicator is not lit Examples LAS DISp MDp response 0 means that the LASER DISPLAY IPD PPD switch is not currently active or it is active but displaying monitor current IPD laser photodiode monitor power is not displayed Las dis MDP response 1 means that the LASER DISPLAY IPD PPD switch is currently active PD power may be displayed for the selected LAS channel LASer DISplay PARAM DEVICE DEPENDENT FRONT PANEL The LASer DISplay PARAM command enables the LASer display to show the LASER parameter values for the selected LAS channel Parameters None Notes This command has the same effect as pressing the PARAMETER SELECT switch while in LASER mode The selected parameter will be displayed for three seconds The actual LASER PARAM display is turned off automatically when a LASER display selection is enabled Each time the command is issued the next LASER parameter will be selected see Section 2 15 In local operation the LASER PARAMETER is displayed by pressing the SELECT switch in the LASER PARAMETER area of the front panel while in LASER mode Examples Laser Display Param action selects a LASER parameter an
122. at 1 Hz Optical Output Power Limit Output off POWER LIMIT light flashes at 1 Hz Voltage Limit CURRENT LIMIT light flashes at 2 Hz Modulation Section The THROUGH TO REAR BNC connector allows a DC to 500 kHz high bandwidth or DC to 10 kHz low bandwidth modulation signal to be applied to the laser The bandwidth specification is measured with a 1 load The modulation port input impedance is 0 5 Q For convenience the THROUGH TO REAR connection allows the modulation signal to be connected via the front panel sent through to the back panel and routed to a Laser module via a jumper cable The transfer ratio of the modulation control signal varies with module model refer to the Laser module instruction manual THROUGH TO REAR Figure 2 24 LDC 3900 MODULATION Section Save and Recall Parameter Functions The Save and Recall parameter functions are used to store and retrieve the LDC 3900 Modular Laser Diode Controller s parameter configurations for future use For example a specific test setup may be saved for later use via the Save function and then another setup may be used presently Then when the user desires to perform the specific test again its setup is simply recalled via the Recall 04_10 LDC 3900 Series 31 OPERATION Save and Recall Parameter Functions function This saves setup time and it reduces the chance of setup error for tests which are repeated periodically Non volatile memory is u
123. ath LASer SET LDI LASer SET MDI LASer SET MDP LASer SET LDI COMMON DEVICE DEPENDENT FRONT PANEL The LASer SET LDI query returns the constant value which is used for both bandwidth modes Parameters None The response is an lt nrf value gt which represents the selected channel s constant set point value in mA Notes In local operation the constant set point is read by selecting or IHBW mode pressing the SET switch in the LASER DISPLAY area of the front panel and then visually reading the LASER display Examples LAS SET LDI response 50 0 means the selected channel s laser output current set point value is 50 0 mA Laser set ldi response 1200 0 means the selected channel s laser output current set point value is 1200 0 mA LASer SET MDI DEVICE DEPENDENT FRONT PANEL The LASer SET MDI query returns the selected channel s laser monitor PD current set point value when CALPD 0 in mA Parameters None The response is an lt nrf value gt which represents the selected channel s constant IPD set point value in mA Notes The monitor photodiode current is directly proportional to the laser optical output power Therefore the IPD set point may be used to control optical output of the laser In local operation the constant IPD set point is read by selecting P mode when CAL PD 0 then pressing the SET switch in the LASER DISPLAY area of the front panel and then visually reading the LASER display
124. ator E E 110 lt SUFFIX PROGRAM DATA gt must have digit following sign E 111 lt SUFFIX PROGRAM DATA gt must have alpha character following operator E 113 lt ARBITRARY BLOCK PROGRAM DATA gt length less than digit count E 114 lt DEFINITE LENGTH BLOCK PROGRAM DATA gt premature end of data E 115 lt PLACEHOLDER PROGRAM DATA gt identifier not valid E 116 Parser syntax error character was not expected E 120 lt program mnemonic gt Lookup word as part of a header path has no commands E 121 lt program mnemonic gt Lookup word as part of a header path is not found E 122 lt program mnemonic gt Lookup cannot find a null entry E 123 lt program mnemonic gt Lookup word within context of current path is not found E 124 lt program mnemonic gt Lookup failed because query command type match failed E 125 lt program mnemonic gt Lookup word within context of common command path is not found E 126 Too few or too many program data elements E 201 lt PROGRAM DATA gt value out of range E 202 lt PROGRAM DATA gt will not convert to valid type E 203 Security violation command is not available without clearance E 204 lt PROGRAM DATA gt suffix type is not valid E 205 lt PROGRAM DATAs is not a Boolean value or word E 206 lt PROGRAM DATA gt will not convert to a signed 16 bit value E 207 lt PROGRAM DATA gt will not convert to an unsigned 16 bit value E 208 lt PROGRAM DATA gt will not convert to a sign
125. ator is orange the TEC display will indicate the set point of the selected operating mode T R or lte This control mode set point display will continue for three seconds and then the display will revert to its former state a measured value For example assume that an Adjust TEC mode is in effect and T is selected as the TEC Mode but the TEC Display R switch is selected and the sensor thermistor resistance is displayed on the TEC display If the Adjust Knob is 04_10 LDC 3900 Series 17 OPERATION LDC 3900 Front Panel turned the TEC display will then show the temperature set point for 3 seconds After 3 seconds the TEC display will revert to showing the measured R value Likewise if the Adjust Knob is turned during operation while a measured Laser value I Ipp or Ppp is being displayed and the Adjust Laser switch is selected and the Laser channel s Output switch is off the Laser display will indicate the set point of the selected operating mode I Iypy or P If the Laser channel s output is on the display will show the selected measurement until the Adjust Knob is turned at a rate of about 2 revolutions per second Then the control mode set point will be displayed This control mode set point display will continue for 3 seconds and then the display will revert to its former state a measured value For example assume that an Adjust LAS mode is in effect the corresponding Output switch is off and is selected
126. ax Diagram lt compound command program header gt A lt compound command program header gt is a compound command heading which may be followed by lt program data gt parameters The LDC 3900 Modular Laser Diode Controller command structure is a tree A compound command or lt compound command program header gt determines the proper command by following a path from the root node This is similar to determining a path for a file by starting with the root directory and listing the intermediate subdirectories The syntax for a lt compound command program header gt is shown in Figure 3 5 on 42 LDC 3900 Series m IX Lightwave 04 10 REMOTE OPERATION ANSI IEEE 488 2 Definitions page 43 The syntax diagram for a lt compound query program header gt is shown in Figure 3 6 on page 43 lt program mnemonic gt gt Figure 3 5 lt compound command program header gt Syntax Diagram lt program lt program mnemonic gt mnemonic gt 20 gt Figure 3 6 lt compound query program header gt Syntax Diagram A lt program mnemonic gt is a command or command path identifier For example the lt PROGRAM MESSAGE gt TEC COND consists of the command COND and the path identifier TEC All of the legal lt compound command program headers gt may be traced by starting from the root node of the command structure and moving down by levels to paths and finally to the co
127. bandwidth mode is selected After this command is issued the LDC 3900 Modular Laser Diode Controller will allow calibration of the current set point measurement and limit if low bandwidth mode is selected This procedure is outlined in the Calibration section of the LASER module instruction manual The calibration defaults to the selected bandwidth setting Therefore it is necessary to select the desired bandwidth I or IHBW and turn the LASER output on before performing the calibration for that bandwidth Calibration is performed at the current set point wherever it is set If the LASER output is not ON the LDC 3900 Modular Laser Diode Controller will beep each time you try to enter this mode indicating a calibration procedural error In remote operation the LASer CAL LDI query may be used to determine if the LDC 3900 Modular Laser Diode Controller is ready for the user to enter a value In local operation the LDC 3900 Modular Laser Diode Controller will beep once when it is ready for the user to enter a value Examples Las CAL Ldl action the LDC 3900 Modular Laser Diode Controller enters calibration mode for LASER current Las Cal LDI action the LDC 3900 Modular Laser Diode Controller enters calibration mode for LASER current 98 LDC 3900 Series MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer CAL LDI DEVICE DEPENDENT FRONT PANEL The LASer CAL LDI query is used to determine t
128. be no LAS or combination module present on channels 2 4 LASer ALL LIMit DEVICE DEPENDENT The LASer ALL LIMit command path is used to get to the global laser limit commands These commands effect all channels regardless of the LAS channel selection The following commands may be reached directly from the LASer ALL LIMit command path LASer LIMit l LASer LIMit MDP LASer LIMit I LASer LIMit MDP LASer ALL LIMit I DEVICE DEPENDENT The LASer ALL LIMit l command sets LASER current limit values for all channels Parameters Four lt nrf value gt s which represents the LASER limit current in mA for each channel in ascending order Notes The current limit is in effect in all modes of operation of a given channel s laser output If the new limit value is lower than the present current set point the current set point will be forced down to the value of the current limit and an E534 error will be generated Examples LAS ALL LIM 80 80 80 80 action the LASER current limit is set to 80 mA for all channels Laser all Limit l 160 100 25 30 action the LASER current limit is set to 160 mA for channel 1 100 mA for channel 2 25 0 mA for channel 3 30 0 mA for channel 4 90 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL LIMit I COMMON DEVICE DEPENDENT The LASer ALL LIMit I query returns the values of all the channels LASER current limit Parameters No
129. be reached directly from the LASer LIMit command path LASer LIMit l LASer LIMit MDP LASer LIMit 1 LASer LIMit MDP MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer LIMit I COMM DEVICE DEPENDENT FRONT PANEL The LASer LIMit l command sets the selected channel s LASER current limit value Parameters An lt nrf value gt which represents the selected channel s LASER limit current in mA Notes The current limit is in effect in all modes of operation of the selected channel s laser output If the new limit value is lower than the present current set point the current set point will be forced down to the value of the current limit and an E534 error will be generated In local operation the limit current is entered by selecting LIM parameter pressing and holding in the PARAMETER SET switch adjusting the Adjust Knob until the desired value is displayed and then releasing the SET switch Examples LAS LIM 1 80 action the selected channel s LASER current limit is set to 80 mA Laser Limit l 160 action the selected channel s LASER current limit is set to 160 mA LASer LIMit I Co DEVICE DEPENDENT FRONT PANEL The LASer LIMit I query returns the value of the selected channel s LASER current limit Parameters None The response is an lt nrf value gt Notes The selected channel s current limit is valid for all modes of Laser operation In local operation the limit current value is read by se
130. by the user in the LDC 3900 Laser Diode Controller for the AD590 The AD590 measurement is calibrated at the factory with C2 1 and C1 0 nominal values The AD590 grades of tolerance vary but typically this means that without adjusting C1 or C2 the temperature accuracy is 1 C over its rated operating range If C1 and C2 are also calibrated the temperature accuracy is 0 2 C over its rated operating range However the AD590 is not perfectly linear and even with C1 accurately known there is a non linear absolute temperature error associated with the device This non linearity is shown in Figure B 1 reprinted from Analog Devices specifications where the error associated with C1 is assumed to be zero 1 0 N ABSOLUTE ERROR DEGREES C 0 1 6 55 150 DEGREES C Figure B 1 AD590 Nonlinearity If a maximum absolute error of 0 8 C is tolerable over the entire temperature range the one point calibration of C1 should be used If C1 is calibrated at 25 C and the intended operating range is 0 to 50 C a maximum error of about 0 2 C may be expected over that operating range If a greater accuracy is desired the two point method of determining C1 and C2 should used Note however the absolute error curve is non linear therefore the constant C2 will vary over different temperature ranges 192 LDC 3900 Series MIL Lightwave LM335 Sensor LM335 Sensor The LM335 is a linear thermal sensor which acts as a co
131. byte register will be set The enable registers normally retain their values at power up as they were at power down unless the power on status clear flag is set true see PSC Chapter 3 Examples LAS ENAB COND 129 action enables the LASER status condition register so that the Open circuit and LASER current limit conditions will be summarized in the status byte bit 3 for the selected LAS channel Laser Enable Cond HFF97 action enables the selected channel s LASER status condition register so that any and all of the above conditions will be reported in the status byte register bit 3 04 10 LDC 3900 Series 109 110 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ENABle COND Parameters Notes Examples DEVICE DEPENDENT The LASer ENABle COND query returns the value of the selected channel s status condition enable register of the LASER operations None The response is the sum of the following 1 LASER Current Limit256 Output is Shorted 2 LASER Voltage Limit512 Output is Outside Tolerance Limit 4 N A 1024 Output On Off State 8 Power Limit 2048 Ready for Calibration Data State 16 Interlock Disabled4096 Calculation Error 32 N A 8192 Error Communicating LASER Board 64 N A 16384 Software Error in LASER Control 128 Open Circuit 32768 LASER EEPROM Checksum Error The selected channel s enabled LASER conditions can be set by using the LASer ENABle COND comman
132. cator is not lit Examples LAS DIS LDV response 0 means that the LASER DISPLAY V switch is not currently active laser voltage is not displayed Las dis Idl response 1 means that the LASER DISPLAY switch is currently active laser voltage may be displayed for the selected LAS channel 04_10 LDC 3900 Series 105 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer DISplay MDI COMM DEVICE DEPENDENT FRONT PANEL The LASer DISplay MDI command sets the laser display to show the monitor photodiode current measurement for the selected LAS channel Parameters None Notes The actual LASER DISPLAY IPD display is turned off automatically when another LASER DISPLAY selection is enabled In local operation the LASER DISPLAY IPD value is displayed by pressing the IPD PPD switch in the LASER DISPLAY area of the front panel If PPD mode appears press the switch again to toggle to the IPD value Examples LAS DIS MDI action enables the LASER display for photodiode current values Laser Disp Mdi action enables the LASER display for photodiode current values LASer DISplay MDI Co DEVICE DEPENDENT FRONT PANEL The LASer DISplay MDI query returns the status of the LASER DISPLAY IPD PPD switch Parameters None The response will be either 0 off or 1 on Notes In local operation the status of the IPD PPD switch is determined by visually inspecting the IPD indicator in the LASER DISPLAY area
133. ce Dependent Commands LASer TOLerance DEVICE DEPENDENT The LASer TOLerance command allows the programmer to determine the selected channel s LASER current tolerance and time window for it to occur in order that the operation complete flag be set after a LASer OUTput 1 command is issued or the LASER set point is changed Parameters Two lt nrf values gt the first represents the LASER current tolerance in mA with a range of 0 1 to 100 0 mA or monitor diode current in uA if the mode is MDP and CALMD 0 and the second represents the time window in seconds with a range of 0 001 to 50 000 seconds Version 3 1 and higher of the LDC 3900 requires both parameters Prior versions of the LDC 3900 allowed the second parameter to be optional This command may be used in conjunction with the common query OPC or common command WAI to delay further program activities until the LASER current reaches its set point to the specifications of the LASer TOLerance command For example if the set point is 40 5 mA tolerance is 1 0 mA for 5 seconds and the LASER output is turned on the user may issue the WAI command to ensure this set point is reached before continuing In this case the selected LAS channel will wait until its LASER current is within 1 0 mA of 40 5 mA for a period of 5 seconds before the next command is executed Notes The LDC 3900 LASER modules default to a tolerance of 10 0 mA for 5 seconds unless changed by the se
134. ce eee 24 TEC Error Indicators 0 0 0 0 ccc eee 24 Laser Mode Section 0 0 00 0 00 c eee ee eee 25 Laser Mode Select 0 00 00 00 ccc eee eee ee 26 Laser Mode Indicators 00 00 00 cece ee ee 26 Laser Display Switch Section 0 00 0 teens 26 Laser Display S6L vico il tt ee ae eee dos 27 Laser Display Indicators and Switches 0 oo oooooooomooo o 27 Laser Parameter Section oo o oooocoooonooooooooo ooo 28 Laser Parameter Select ooooooooooonro 28 Laser Parameter Set o ooooooooooo eee 29 A E creda ee Ses 29 A a aye ata ae a aes a ree 29 GALPD Espasa ans ata apes ars ait anida 29 Laser Channel Indicators 0 000000 cece eee eee 30 Laser Error Indicators cv ear dana hee we dated a Ok ee ee ears 30 ii LDC 3900 Series ML Lightwave Modulation Section 0 0c een eens 31 Save and Recall Parameter Functions 200000e eee 31 Rear Panel Controls and Connections 00000 o 33 GPIB CONNECTION sac ee axe a ahha ed Ca ed eee Ra 33 Modulation from Front Connector 00 00 cece eee 34 Earth Ground Connector 0000 ees 34 General Operating Procedures 0 0 00 cece cee ee 34 Warm up and Environmental Considerations ooooooooo 34 TEC Mode Operation 0 0000 tte eee 34 Laser Mode Operation 0000 cece eee 35 Simultaneous TEC and Laser Mode Operatio
135. cending order Each value must be between 1 300 the value will be stored to the nearest of 1 3 10 30 100 or 300 for the given TEC channel Notes If an entered value is greater than 300 an error E222 will be generated and the GAIN parameter for the given channel will not be changed If an entered value is less than 1 an error E223 will be generated and the GAIN parameter for the given channel will not be changed Examples TEC ALL GAIN 100 100 100 100 action the TEC control loop gains for all TEC channels are set to 100 Tec all gain 3 3 30 10 action the TEC control loop gain for channels 1 and 2 are set to 3 channel 3 gain is set to 30 channel 4 gain is set to 10 TEC ALL GAIN DEVICE DEPENDENT The TEC ALL GAIN query returns the values of the control loop gain for all channels in ascending order Parameters None The response is four lt nrf value gt s representing the gain for each channel in ascending order Each gain value is one of the following 1 0 3 0 10 0 30 0 100 0 or 300 0 Notes If a value between 1 and 300 other than 1 3 10 30 100 or 300 is entered via the GAIN command the nearest valid value will be stored Examples TEC All Gain response 30 0 30 0 30 0 30 0 means the control loop gain for all TEC channels is set to 30 Tec ALL GAIN response 100 0 10 0 30 0 30 0 means the control loop gain for TEC channel 1 is set to 100 the gain for channel 2 is set to 10 and the gain
136. ch modules are present CHECKSUM response 3812 is the checksum of the present configuration of parameters on the instrument DELAY Parameters Notes Examples 86 LDC 3900 Series DEVICE DEPENDENT The DELAY command causes the execution of commands to be delayed by a user defined time This command is similar to the WAI common command except that execution resumes after the specified number of milliseconds instead of waiting for the Operation Complete flag to be set An lt nrf value gt which represents the delay time in milliseconds The Operation Complete flag is held false until the delay period elapses but the OPC query will not execute until the delay period has elapsed This command is useful for creating delays which don t require a lot of program code and don t tie up the GPIB during execution DELAY 500 action Further commands and queries are not executed until 0 5 seconds have elapsed from the time this command is executed Tec T 22 Delay 2000 Tec T actions The TEC is set to 22 0 C then the LDC 3900 Modular Laser Diode Controller waits for about 2 0 seconds before returning the measured temperature MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands ERRors COMMON DEVICE DEPENDENT The ERRors query returns a list of command and device errors which have occurred since the last query These errors are notated by a number which corresponds to the type of error which occur
137. character data substitute such as ON or OFF Examples BEEP 0 action The beeper is disabled BEEP 1 action The beeper is enabled for normal operation BEEP 2 action The beeper is beeped once 04_10 LDC 3900 Series 85 COMMAND REFERENCE LDC 3900 Device Dependent Commands BEEP Parameters Notes Examples DEVICE DEPENDENT The BEEP query returns the enable status of the LDC 3900 Modular Laser Diode Controller s beeper None A response of 0 OFF totally disabled 1 ON enabled for normal operation Disabling the BEEP will prevent the audible beeper signal from working during front panel operation including the calibration signals The beeper is normally enabled unless it is specifically disabled via the BEEP 0 remote command BEEP response 0 means the beeper is disabled Beep response 1 means the beeper is enabled for normal operation CHECKSUM Parameters Notes Examples DEVICE DEPENDENT The CHECKSUM query returns an integer value which is the summation of all pertinent parameters of the present configuration None The response consists of an integer value The response value may be stored and compared at a later time to verify that the present configuration of the instrument is the same as expected This feature works well with the RCL recall command as a means of verifying a stored setup The checksum does not test the functionality of the instrument or whi
138. cted TEC channel Notes This value also limits the TEC booster output signal voltage to a value which is proportional to the TEC limit current approximately 1 V A If the new limit value is lower than the present ITE set point the ITE set point will be forced down to the value of the ITE limit and an E434 error will be generated In local operation the ITE limit is set by selecting the LIM ITE parameter pressing the PARAMETER SET switch adjusting the Adjust Knob until the desired value appears on the TEC display and then releasing the SET switch Examples TEC LIM ITE 3 5 action the TEC current limit is set to 3 500 amps for the selected TEC channel Tec Limit lte 4 0 action the TEC current limit is set to 4 000 amps for the selected TEC channel 04_10 LDC 3900 Series 159 160 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC LIMit ITE DEVICE DEPENDENT FRONT PANEL The TEC LIMit ITE query returns the value of the TEC s TE current limit for the selected TEC channel Parameters None The response is an lt nrf value gt Notes The response value is in amps In local operation the ITE limit value is read by pressing the TEC PARAMETER SELECT switch until the LIM ITE indicator is lit and reading the value on the TEC display Examples TEC LIM ITE response 3 5 means the TEC output current limit is 3 500 amps for the selected TEC channel Tec Limit lte response 4 0 means the TE
139. ction until the T mode is selected Press the Select switch in the Parameter section and check the setting of LIM ly LIM Ty GAIN and C1 C2 and C3 to insure that they are compatible with the equipment you are using Refer to TEC Parameter Section on page 21 if you need to change them If a pre configured setup is to be recalled use the Recall feature see Save and Recall Parameter Functions on page 31 and then recheck the parameter settings for confirmation Press the T switch and Set switch in the TEC Display Switch Section and check the set point temperature If it requires changing turn the knob until the desired value is displayed Turn the TEC output on by pressing the Output switch for the desired TEC channel The unit will automatically control the temperature to the set point If multiple TEC modules are to be controlled repeat steps c g for the other TEC channels During operation only one TEC channel may be monitored at a time on the front panel However if a TEC module has an error condition and that TEC channel is not presently selected its Channel Indicator will blink the TEC display Error Indicator will also blink Select the TEC channel with the error condition via the Adjust LAS TEC switch The error condition and all other information for that TEC channel will be displayed When the LDC 3900 is powered off the state of the unit at power down is saved in non volatile memory Calibration data are sto
140. d The LASER condition status can be monitored by the LASer COND query LAS ENAB COND response 17 means that the Laser Current Limit and Interlock disabled LASER conditions for the selected LAS channel will be reported in summarized form to the status byte bit 3 Radix Hex Laser Enable Cond response HFF97 means that all of the above conditions will be reported in summarized form to the status byte bit 3 for the selected LAS channel LDC 3900 Series LASer ENABle EVEnt Parameters Notes Examples DEVICE DEPENDENT The LASer ENABle EVEnt command sets the status event enable register of the LASER operations for the selected LAS channel These events are summarized in bit 2 of the status byte register An lt nrf value gt whose sum represents the bits which are enabled 1 LASER Current Limit256 Output is Shorted 2 LASER Voltage Limit512 Output Changed to be In Out of Tolerance 4 N A 1024 Output On Off State Changed 8 Power Limit 2048 New Measurements Taken 16 Interlock State Changed4096 Calculation Error 32 N A 8192 Error Communicating LASER Board 64 N A 16384 Software Error in LASER Control 128 Open Circuit32768 LASER EEPROM Checksum Error The enabled LASER events for the selected LAS channel can be read by using the LASer ENABle EVEnt query The selected channel s LASER event status can be monitored by the LASer EVEnt query The enable registers normally retain their va
141. d 3 and turns the laser outputs on for channels 2 and 4 LAS ALL OUT 1 1 1 1 action turns the laser output on for all channels LASer ALL OUTput Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT The LASer ALL OUTput query returns the status of all the laser channels OUTPUT switches None The response is four lt nrf value gt s separated by commas 0 off 1 on Although the status of the switch is on the corresponding channel s output may not have reached the set point value On LAS TEC combination modules a 1 response indicates that the channel s output switch is enabled Either the LAS or the TEC output or both may be on In the case of only the TEC or LAS output being on the corresponding OUTPUT led will blink Las ALL OUT response 0 0 0 0 means that the OUTPUT switch is disabled on all channels devices may be safely disconnected or connected at the LAS output terminals of any channel LAS All OUT response 1 0 0 0 means that the LAS OUTPUT switch is enabled for channel 1 LASER output is present for channel 1 For channels 2 4 the laser outputs are off MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer CALMD COMMON DEVICE DEPENDENT FRONT PANEL The LASer CALMD command sets the laser s photodiode feedback responsivity the CAL PD parameter on the selected LAS channel Parameters An lt nrf value gt in microamps milliwatt Notes If the param
142. d a brewed dedi nats iene lea 51 OPG sede ey deeded ogee pees ead ke een Cee Ree Se eee 52 OPC ice A A ieee dee peed ad hans edad hes 52 PSG o Spinetti tae A A a id 53 PSC e e daa ka AA A Aa wee ede ade ea 54 PUD perrita da wee eee E eed eee 54 PUD tera aneia wheelie A adobe eas eka bees 55 RGLikvacicak hid yarns pha Peay eked ae eens oie s 8G dee ee dees 55 RST 242 var ead dbo asia seaweed eed pbb weed ae ben ad eae eres 56 SA Vivi shad eg Ta eps dp eee ao ee eed Gees ee eee Se eS 57 SRE ewig A A HU GRRE OMG Ne eh ad 57 ISRAEL cs ii a ese aye meee ee ei 59 SIIB oia ae dard anaes Loa ee he a 59 TST ove o uo eee free eee EOE 60 WAL ii dha eed AA be ae aid Qik oleh bailing elk ie ete 60 Advanced Programming 0 00 e eee tae 61 Path Specification 0 0 0 ene eens 61 Timing Considerations 0 0 0 0 ccc ene ens 62 Error Messages xiii ca ee ele ee ee ee eee 63 Status Reporting 2 0a dy nee ed eee ee ed EEE a ede 64 Event and Condition Registers 000 cece e eee ee eee 64 Operation Complete Definition 0 00 c eee ooo 66 Command Timing and Completion 0000 cece eee eee 66 Output Off Registers 0 0 0 0 eee eee NNG 68 Input Buffer and Output Data 0 0 00 eee 70 Chapter 4 Command Reference Command Set Overview occcccccc tees 73 Substitute Parameter Names 0000 0 cece eee eee 74 Compound Command Structure
143. d displays its value for the selected LAS channel LAS DIS PARAM action selects a LASER parameter and displays a its value for the selected LAS channel LASer DISplay SET DEVICE DEPENDENT FRONT PANEL The LASer DISplay SET command sets the laser display to show the set point of the selected LASER DISPLAY mode for the selected LAS channel Parameters None Notes Using this command has the same effect as physically holding the DIS SET switch down in Examples Las Dis Set action enables the LASER display for the set point of the selected mode LDI MDI IPD or MDP PPD LAS Dis Set action enables the LASER display for the set point of the selected display mode 04_10 LDC 3900 Series 107 108 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer DISplay SET Co DEVICE DEPENDENT FRONT PANEL The LASer DISplay SET query returns the status of the LASER DISPLAY SET switch Parameters None The response will be an lt nrf value gt Notes The set point display will not time out when REMOTE operation is used It will be continuously displayed In local operation the status of the SET switch is determined by visually inspecting the LED on the LASER DISPLAY SET switch lit ON Examples LAS DISPLAY SET response 0 means the measured value of the selected LAS channel is enabled for the LASER display Las Dis Set response 1 means the set point value of the selected LAS channel is
144. d to control the TEC output in R mode only Using the R mode the user may also monitor the temperature of the TEC load via a remote algorithm of his her own design If an entered value is greater than 450 an error E222 will be generated and the R set point parameter for the given channel will not be changed If an entered value is less than 0 001 an error E223 will be generated and the R set point parameter for the given channel will not be changed Examples TEC ALL R 20 5 20 5 20 5 20 5 action sets the set point thermistor or RTD resistance to 20 5 kW or sets the AD590 current to 20 5 mA or sets the LM335 voltage to 20 5 mV for all channels TEC All Mode R TEC All R 10 15 3 15 7 20 5 action For channel 1 sets the set point thermistor or RTD resistance to 10 0 kW or the AD590 current to 10 0 mA or the LM335 voltage to 10 0 mV for the channel 1 The TEC output sensor is controlled to that value if the output is on on channel 1 For channel 2 sets the set point thermistor or RTD resistance to 15 3 kW or the AD590 current to 15 3 mA or the LM335 voltage to 15 3 mV for channel 2 The TEC output sensor is controlled to that value if the output is on on channel 2 For channel 3 sets the set point thermistor or RTD resistance to 15 7 kW or the AD590 current to 15 7 mA or the LM335 voltage to 15 7 mV for channel 3 The TEC output sensor is controlled to that value if the output is on on channel 3 For channel 4 sets
145. display and all of the TEC section s indicator LEDs will be turned off Examples TEC DIS 0 action the TEC display will be blanked and all of the TEC indicator LEDs will be turned off tec dis 1 action the TEC display and LEDs will be enabled tec display on action the TEC display and LEDs will be enabled 146 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC DISplay Comm DEVICE DEPENDENT FRONT PANEL The TEC DISplay query returns the contents of the TEC display Parameters None The response is a character string Notes Returns the actual 6 character string from the output buffer to the TEC display If the display is disabled it returns In local operation the TEC display value is read by visually inspecting the TEC display Examples TEC DIS response 99 9 means 99 9 is on the TEC display Tec DISp response 0 6 means 0 6 is on the TEC display TEC DISplay Common DEVICE DEPENDENT FRONT PANEL The TEC DISplay command path is used to get to the LDC 3900 s TEC display commands The following commands may be reached directly from the TEC DISplay command path TEC DISplay ITE TEC DISplay SET TEC DISplay ITE TEC DISplay SET TEC DISplay PARAMTEC DISplay T TEC DISplay R TEC DISplay T TEC DISplay R TEC DISplay ITE COMMC DEVICE DEPENDENT FRONT PANEL The TEC DISplay ITE command enables the TEC display to show the TE current measureme
146. display shows 0 6 LASer DISplay MMON DEVICE DEPENDENT FRONT PANEL The LASer DISplay command path is used to get to the selected LAS channel s laser display commands The following commands may be reached directly from the LASer DISplay command path LASer DISplay LDI LASer DISplay MDI LASer DISplay PARAM LASer DISplay LDI LASer DISplay MDI LASer DISplay SET LASer DISplay LDV LASer DISplay MDP LASer DISplay SET LASer DISplay LDV LASer DISplay MDP LASer DISplay LDI Co DEVICE DEPENDENT FRONT PANEL The LASer DISplay LDI command sets the laser display to show the constant current measurement for the selected LAS channel Parameters None Notes The actual LASER display is turned off automatically when another LASER DISPLAY selection is enabled In local operation the LASER value is displayed by pressing the switch in the LASER DISPLAY area of the front panel Examples LAS DIS LDI action enables the LASER display for current values Las Display LDI action enables the LASER display for current values 104 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer DISplay LDI COMM DEVICE DEPENDENT FRONT PANEL The LASer DISplay LDI query returns the status of the LASER DISPLAY switch Parameters None The response is either 0 off or 1 on Notes In local operation the status of the switch is determined by visually inspecting the
147. dy state during the calibration cycle is indicated by a beep which is issued by the LDC 3900 when it is ready for a value to be entered if the beeper is enabled Examples Tec CAL SEN response 1 means the LDC 3900 is ready for the user to enter a resistance value via the TEC R command Tec Cal Sensor response 0 means the LDC 3900 is not yet ready for the user to enter a resistance value TEC CAL V DEVICE DEPENDENT The TEC CAL V command enters the TEC s voltage calibration mode for the selected channel 39034 only Parameters None Notes After this command is issued the front panel is disabled and the LDC 3900 will automatically enter the TEC voltage calibration mode This calibration procedure is outlined in the Calibration section of the TCM 39034 instruction manual This calibration may only be done via GPIB TEC CAL V query may be used to determine if the LDC 3900 is ready for the user to enter a value Examples Tec CAL V action the TCM 39034 module enters TEC voltage calibration mode TEC CAL V DEVICE DEPENDENT The TEC CAL V query is used to determine that the LDC 3900 is ready for a value to be entered during the calibration cycle of the TEC CAL V mode 39034 only Parameters None The response is an lt nrf value gt 1 ready O not ready Notes This query can be used to poll the LDC 3900 after the TEC CAL V command to determine if it is waiting for a value If the response is 1 the LDC 3900
148. e 4 N A 1024 Output On Off Changed 8 High Temperature Limit 2048 New Measurements Taken 16 TEC Interlock Disabled 4096 Calculation Error 32 Booster Enable 8192 Internal Communication Error with TEC Board 64 Sensor Open 16384 Software Error 128 TE Module Open 32768 TEC EEPROM Checksum Error Notes The enabled TEC events for the selected TEC channel can be read by using the TEC ENABle EVEnt query The enabled TEC event status for the selected TEC channel can be monitored by the TEC EVEnt query The enable registers normally retain their values at power up as they were at power down unless the power on status clear flag is set true see PSC Chapter 3 Examples Tec Enab EVENT 160 action enables the TEC status event register so that the TE Module Open and Booster Changed conditions for the selected TEC channel will be reported in summarized form to the status byte register bit 1 Tec Enable EVEnt HFFFB action enables the TEC status event register so that any and all of the above events for the selected TEC channel will be reported in summarized form to the status byte register bit 1 04 10 LDC 3900 Series 153 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ENABle EVEnt COMMON DEVICE DEPENDENT The TEC ENABle EVEnt query returns the value of the status event enable register of the TEC operations for the selected TEC channel Parameters None The response is the sum of the fol
149. e the measured laser output current would be read by pressing the switch and visually reading the LASER display Examples LAS Idi response 30 0 means the selected channel s measured laser output current is 30 0 mA Laser LDI response 100 0 means the selected channel s measured laser output current is 100 0 mA LASer LDV COMM DEVICE DEPENDENT The LASer LDV command sets the selected channel s laser voltage for calibration of the laser voltage measurement Parameters An lt nrf value gt which represents the selected channel s laser output voltage in volts Notes Set point is the same for both low and high bandwidth output modes Examples Las LDV 4 action enters a value of 4 000 volts LAS Idv 1 025 action enters a value of 1 025 volts LASer LDV Commo DEVICE DEPENDENT The LASer LDV query returns the value of the selected channel s measured laser voltage Parameters None The response is an lt nrf value gt Notes Response is the selected channel s measured laser output voltage for either low or high bandwidth modes This measurement is updated approximately once every 600 mSec Examples LAS Idv response 3 03 means the measured laser output voltage is 3 03 volts Laser LDV response 1 0 means the measured laser output voltage is 1 000 volts LASer LIMit DEVICE DEPENDENT FRONT PANEL The LASer LIMit command path is used to get to the selected LAS channel s laser limit commands The following commands may
150. e 75 the required letters for each command are shown LDC 3900 Device Dependent Commands on page 75 contains a detailed account of each command and tells which are also supported by front panel operations In LDC 3900 Device Dependent Commands on page 75 each command is spelled out with the required letters in upper case and the optional letters in lower case The optional letters may be used to improve program readability Substitute Parameter Names For clarity in programming the Boolean values of one and zero may also be represented by the appropriate substitute parameter names as shown Table 4 1 Substitute Parameter Names SUBSTITUTE NAME VALUE ON 1 OFF 0 OLD 1 NEW 0 TRUE 1 FALSE 0 The ON parameter name could be used in place of the 1 in the example in Command Set Overview on page 73 as follows TEC DIS ON Compound Command Structure Many of the LDC 3900 remote commands require a compound structure This is done to distinguish between different commands of the same type and to designate which type of module the command is intended TEC thermoelectric controller or LAS laser current source The compound command structure is similar to a directory path structure as found in DOS For example commands which deal with the LDC 3900 Modular Laser Diode Controller s TEC have the path TEC as in the command to set the TEC display to measured resistance TEC DIS R 74
151. e Limit 9 Outside of TEC Tolerance Condition 2 N A 10 Sensor Shorted while output on Condition 3 High Temperature Limit 11 N A 4 N A 12 Software Error Condition 5 Booster Changed while output 13 N A on event 6 Sensor Open while output on 14 N A Condition 7 TEC Module Open output on 15 N A Condition Table 3 2 LDC 3900 Default Settings for Output Off Registers LASER Output Off Registers TEC Output Off Registers 0 disabled 8 N A 0 disabled 8 enabled 1 disabled 9 disabled 1 disabled 9 disabled 2 disabled 10 disabled 2 N A 10 enabled 3 enabled 11 enabled 3 enabled 11 N A 4 N A 12 disabled 4 N A 12 disabled 5 disabled 13 enabled 5 enabled 13 N A 6 disabled 14 enabled 6 enabled 14 N A 7 N A 15 enabled 7 enabled 15 N A Input Buffer and Output Data The Input buffer of the LDC 3900 is 80 bytes However the user s lt PROGRAM MESSAGE gt may be longer The output response data of the LDC 3900 is sent in blocks of up to 80 bytes in length It is sent using high speed DMA within the LDC 3900 Modular Laser Diode Controller but may be of indefinite length Although some commands have a definite length response such as the MESsage query the response length is indefinite because the LDC 3900 will respond to multiple queries in a single response output The user may enter as many queries as desired in a single input message and
152. e calculation of temperature over wide temperature ranges Table A 1 shows the results of using equation 1 to fit the resistance verses temperature characteristic of a common 10K ohm at room temperature thermistor Equation 1 will produce temperature calculation errors of less than 0 01 C over the range 20 C to 50 C MIL Lightwave LDC 3900 Series 185 A The Steinhart Hart Equation Error T C Error T C R T Actual Third Order Fit Eq 1 First Order Fit Eq 2 32128 0 00 0 0000 0 23 19549 10 00 0 0005 0 11 12262 20 00 0 0001 0 06 9814 25 00 0 0002 0 06 7908 30 00 0 0009 0 07 5331 40 00 0 0003 0 15 3542 50 00 0 0030 0 30 1 Resistance of a 10 kQ Dale 1T1002 5 thermistor 2 Constants A 0 99 10 B 2 57 10 C1 0 99 C2 2 57 Table A 1 Comparison of Curve Fitting Equations For the LDC 3900 the Steinhart Hart equation has been simplified to a first order polynomial 1T A B InR Equation 2 This equation is easier to solve and provides adequate results Table A 1 also shows that the use of Equation 2 introduces temperature errors of less than 0 3 C over the range 20 C to 50 C with accuracies of up to 0 06 C over smaller temperature ranges near room temperature 186 LDC 3900 Series MIL Lightwave 04 10 The Steinhart Hart Equation THERMISTOR R T CURVES FOR VARYING ROOM TEMP RESISTANCES
153. e the command length they may not necessarily optimize the speed of program execution The following tip may be useful if soeed of execution of a command is critical If a command follows a semicolon in a command string and it is not at the root level using the colon will aid the software in locating the command and time will be saved 62 LDC 3900 Series im IL Lightwave 04 10 REMOTE OPERATION Error Messages For example the following command string will execute slightly faster as shown than it would if the first colon after the second semicolon was not included This would save the time of two binary searches one at the LAS DEC level and one at the LAS level LAS DIS Set DEC ITEC DIS T In other cases the hardware may not be able to react as quickly as the commands are executed For example if the set point is greatly incremented i e by 10 C and a measurement is taken before that new set point temperature has been reached a decision based on the accuracy of the measured value may not produce the desired reaction In other words the test could be invalid due to a premature measurement For cases like this the WAI command is useful The WAI command will suspend the execution of the next command until the previous command has been completed With v3 2 and higher firmware the LDC 3900 has the capability of setting many of its parameters and reading most of its measurements in a syst
154. e used to determine if the LDC 3900 Modular Laser Diode Controller is ready for the user to enter a value Examples Las CAL Ldv action the LDC 3900 Modular Laser Diode Controller enters calibration mode for LASER voltage Las Cal LDV action the LDC 3900 Modular Laser Diode Controller enters calibration mode for LASER voltage LASer CAL LDV C DEVICE DEPENDENT The LASer CAL LDV query is used to determine that the LDC 3900 Modular Laser Diode Controller is ready for a value to be entered during the calibration cycle of the LASer CAL LDV mode for the selected LAS channel Parameters None The response will be either 1 ready or 0 not ready Notes After this query is issued and a response of 1 is received the LDC 3900 Modular Laser Diode Controller will be ready for the user to enter a current value via the LASer LDV command see the Calibration section of the LASER module instruction manual Examples LASer CAL LDV response 1 means the LDC 3900 Modular Laser Diode Controller is ready for the user to enter a voltage value via the LASer LDV command LASer Cal LdV response 0 means the LDC 3900 Modular Laser Diode Controller is not yet ready for the user to enter a LASER voltage value LDC 3900 Series 99 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer CAL MDI Comn DEVICE DEPENDENT FRONT PANEL The LASer CAL MDI command is used to enter the LASER photodiode current calibration mode for the selec
155. ed 32 bit value E 209 lt PROGRAM DATA gt will not convert to an unsigned 32 bit value E 210 lt PROGRAM DATA gt will not convert to a floating point value E 211 lt PROGRAM DATA gt will not convert to a character value E 212 lt PROGRAM DATA gt will not convert to a byte array pointer E 213 lt PROGRAM DATAs is incorrect block data length E 214 lt PROGRAM DATA gt length exceeds maximum LDC 3900 Series MIL Lightwave 04 10 ERROR MESSAGES CHAPTER Table 5 2 LDC 3900 Modular Laser Diode Controller Error Message Codes Error Code Explanation E 219 Present modular configuration doesn t match that of stored setting E 222 Parameter value is over range and not used E 223 Parameter value is under range and not used E 301 A lt RESPONSE MESSAGE gt was ready but controller failed to read it Query error E 302 Device was addressed to talk but controller failed to read all of the lt RESPONSE MESSAGE gt Query error E 401 TEC external Temp Limit interlock disabled output E 402 Sensor open disabled output E 403 TEC module open disabled output E 404 TEC Current limit disabled output E 405 TEC Voltage limit disabled output E 407 TEC high temperature limit disabled output E 408 Booster change disabled output E 409 Sensor change disabled output E 410 TEC out of tolera
156. ed in conjunction with the TEC COND to test for and delay further program activities until the TEC temperature reaches its set point to the specifications of the TEC TOLerance command For example if the set point is 10 C tolerance is 0 2 C for 5 seconds and the TEC output is turned on the user may issue the TEC COND query and read back the response to ensure this set point is reached before continuing In this case the selected TEC channel will not set bit 9 of the TEC condition register until its TEC load temperature is within 0 2 C of 10 C for a period of 5 seconds In ITE mode the temperature parameter is not used A fixed value of 10 mA is used instead of the temperature parameter and only the time window may be adjusted In R mode the default values of set point tolerance should not be used Since 0 2 translates to essentially 0 ohms it is very difficult to maintain a zero error for more than two measurement cycles 1 2 seconds Examples Tol 0 5 10 action the selected TEC channel s TEC controller will be in tolerance when the temperature is within 0 5 C for a period of 10 000 seconds TOLer 0 1 1 05 action the selected TEC channel s TEC controller will be in tolerance when the temperature is within 0 1 C for a period of 1 050 seconds TEC MODE ITE TOLer 10 action the selected TEC channel s TEC controller is set for ITE mode and will be in tolerance when the ITE current is within 10 mA for a period of 10 000 seconds
157. effect In local operation the T set point value is read by pressing the TEC DISPLAY SET switch while in T mode and visually reading the TEC display TEC SET T response 33 4 means the constant T set point is 33 4 C for the selected TEC channel Tec Set t response 4 0 means the constant T set point is 4 0 C for the selected TEC channel TEC STB Parameters Notes Examples DEVICE DEPENDENT The TEC STB query is used to read back the selected TEC channel s status summaries for conditions and events This value is used to determine which TEC channel s have conditions and or events which have been summarized and reported to the Status Byte Register which is read via the STB query None The response is the sum of the following 1 TEC Event Status Register Summary 2 TEC Condition Status Register Summary If the Status Byte Register is read via the STB and a TEC condition or event is summarized in bits 1 or 0 any or all of the enabled TEC channels may have been responsible The TEC STB may then be used to poll each of the TEC channels to determine which channel s summarized conditions or events have been reported Tec STB response 2 means the selected TEC channel s condition register caused summary bit 2 of the Status Byte Register to be set TEC STB response 3 means the selected TEC channel s condition and event registers caused summary bits 1 and 0 of the Status Byte Register to be set
158. efinition on page 66 have been satisfied The WAI common command is an example of a sequential command which forces the next command to wait until the no operation pending flag is true This is LDC 3900 Series MIL Lightwave 04_10 REMOTE OPERATION Status Reporting essentially the same as waiting for the OPC flag to become true because the no operations pending flag is used to set the OPC flag bit O of the Standard Event Status Register Whenever there is any output response data in the Output Queue bit 4 is set in the Status Byte Register Whenever there is any error message in the Error Queue bit 7 is set in the Status Byte Register LDC 3900 Series 67 Na a REMOTE OPERATION TER Y Status Reporting Output Off Registers The Output Off Enable Registers allow the user to determine which conditions and events in the TEC and Laser controllers will cause their outputs to be turned off These registers are configured in a manner which is similar to the status reporting registers However their outputs are not reported in the Status Byte Register Rather they go to the hardware which controls the output switching The events and conditions which may be set to cause the TEC and Laser outputs to be turned off are shown in Figure 3 12 on page 68 and Figure 3 13 on page 69 Note that Figure 3 12 on page 68 and Figure 3 13 on page 69 represent one module each There can be up to four of each of the Output Off registers
159. em wide way The LAS ALL and TEC ALL commands allow the user to set or read all of the channels on the LDC 3900 at once without having to select each channel individually via the TEC CHAN and LAS CHAN commands This shortcut can increase GPIB throughput significantly especially when four combination modules are used Refer to Chapter 4 for details Error Messages Error messages may appear on the TEC or Laser displays when error conditions occur which force the output off or reflect hardware errors in the respective functions of the LDC 3900 Modular Laser Diode Controller For example a module open error in the TEC side of the LDC 3900 will be displayed on the TEC display In most cases the error message will appear for three seconds and then the display will revert to its former state In the case of multiple error messages the LDC 3900 will show each new message as soon as it is detected In remote operation the current error list can be read by issuing the ERR query When this is done a string will be returned containing up to 10 of the error messages which are currently in the error message queue Appendix D contains an explanation of the error messages which may be reported remotely by the LDC 3900 Modular Laser Diode Controller LDC 3900 Series 63 y REMOTE OPERATION _ Status Reporting Status Reporting Figure 3 11 on page 65 shows the status reporting scheme of the LDC 3900 Modular Laser Diode Controller E
160. en better in the future LDC 3900 xv Co id xvi LDC 3900 MIL Lightwave CHAPTER 1 INTRODUCTION AND SPECIFICATIONS i B a a a El a a E E B E a E E This manual contains operation and maintenance information for the LDC 3900 Modular Laser Diode Controller and optional Model 1231 GPIB IEEE 488 2 Interface If you want to get started right away read Chapter 2 which covers Operation first In the following chapters there are three areas of discussion one for functions which are common to both the TEC and the Laser controller one for the functions which pertain to the TEC controller only and one for functions which pertain to the Laser current source only Product Overview The LDC 3900 Modular Laser Diode Controller may be configured as a combination current source temperature controller It may also be configured with only current sources or only temperature controllers The current sources provide high stability outputs with fully redundant current limit and multiple laser protection features The temperature controllers can work with most thermistors and TE modules to deliver precision laser temperature control over a wide range of temperatures The LDC 3900 s fast sophisticated GPIB lets you automate your experiment MIL Lightwave LDC 3900 Series 1 INTRODUCTION AND SPECIFICATIONS _ Product Overview Available Options and Accessories Options and accessories available for the LDC 3900 include the followin
161. enabled for the LASER display LASer ENABle IMON LDC 3900 Series DEVICE DEPENDENT The LASer ENABle command path is used to get to the selected LAS channel s laser status enable commands and queries The following commands may be reached directly from the LASer ENABle command path LASer ENABle CONDLASer ENABle EVEnt LASer ENABle COND LASer ENABle OUTOFF LASer ENABle EVEntLASer ENABle OUTOFF MIX Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ENABle COND COMMON DEVICE DEPENDENT RON The LASer ENABle COND command sets the condition status enable register of the selected channel s LASER operations for summary in bit 3 of the status byte and generation of service requests Parameters An lt nrf value gt whose sum represents the enabled bits 1 LASER Current Limit 256 Output is Shorted 2 LASER Voltage Limit512 Output is Outside Tolerance Limit 4 N A 1024 Output On Off State 8 Power Limit 2048 Ready for Calibration Data State 16 Interlock Disabled4096 Calculation Error 32 N A 8192 Error Communicating LASER Board 64 N A 16384 Software Error in LASER Control 128 Open Circuit32768 LASER EEPROM Checksum Error Notes The enabled or disabled LASER conditions of the selected channel can be read by using the LASer ENABle COND query The LASER condition status can be monitored by the LASer COND query If any of the enabled LASER conditions are true bit 3 of the status
162. enoted by the solid box next to the Local label in the upper left corner of the command description The error messages which may be displayed on the LDC 3900 front panel are listed in Chapter 5 A short BASIC program example for remote operation of the LDC 3900 Modular Laser Diode Controller is given in LDC 3900 Programming Examples on page 175 The common GPIB ANSI IEEE 488 2 commands which are supported by the LDC 3900 Modular Laser Diode Controller are described in Chapter 3 Command Set Overview There are two types of device commands commands which cause the LDC 3900 Modular Laser Diode Controller to do something and queries which return a stored value or state of the instrument Queries must be terminated with a question mark while commands may require a parameter s to follow STEC DIS 1 For example the 1 in the command TEC DIS 1 enables the LDC 3900 Modular Laser Diode Controller TEC display while a 0 would disable blank the MIX Lightwave LDC 3900 Series 73 COMMAND REFERENCE p Command Set Overview TEC display Table 4 1 on page 74 contains the allowed substitute mnemonics for 1 and 0 This command emulates the front panel operation of 1 selecting the TEC display section of the front panel 2 selecting the display section and 3 turning it on Most of the commands which emulate the front panel operation are just as intuitive see Table 4 2 on page 75 In Table 4 2 on pag
163. ent channel s CAL PD monitor responsivity constant LAS CALMD NONE Returns the present channel s CAL PD monitor responsivity constant LAS CAL LDI NONE Used to enter current calibration mode on the present LAS channel LAS CAL LDI NONE Returns the ready state for entering a constant calibration value on the present LAS channel LAS CAL LDV NONE Used to enter the laser voltage calibration mode on the present LAS channel LDC 3900 Series MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION LAS CAL LDV NONE Returns the ready state for entering the present channel s laser voltage calibration value LAS CAL MDI NONE Used to enter the monitor photodiode current calibration mode on the present LAS channel LAS CAL MDI NONE Returns the ready state for entering the monitor PD current calibration value on the present LAS channel LAS CHAN 1 Used to select the LAS adjustment channel LAS CHAN NONE Returns the number of the LAS adjustment channel LAS COND NONE Returns the value of the present LAS condition register LAS DEC 0 1 0r2 Used with LAS STEP command to decrement the set point value by one or more steps on the present LAS channel LAS DIS 1 Turns the LAS display on or off LAS DI
164. erated and the LIM THI parameter will not be changed If an entered value is less than 99 9 an error E223 will be generated and the LIM THI parameter will not be changed If the new limit value is lower than the present temperature set point the temperature set point will be forced down to the value of the limit and an E434 error will be generated The default setting of the TEC outoff enable register for the selected TEC channel forces the selected TEC output to be shut off if the high temperature limit is reached See the TEC ENABle OUTOFF command TEC ALL LIM THI 100 100 100 100 action sets the TEC load temperature limit to 100 0 C for the all channels Tec All Lim thi 30 3 100 50 50 action sets the TEC load temperature limit to 30 3 C for channel 1 100 0 C for channel 2 and 50 0 C for channels 3 and 4 MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL LIMit THI COMM DEVICE DEPENDENT The TEC ALL LIMit THI query returns the values of the TEC load s high temperature limit for all channels in ascending order Parameters None The response is four lt nrf value gt s one for each channel in ascending order Notes A given temperature limit is valid for R and T modes of TEC output operation for a given TEC channel If a given high temperature limit is set too low the corresponding TEC output may not be able to be turned on if the high temperature condition is also used to turn the
165. erial number LL represents the hardware revision level OO represents option information MMDDYY represents the date of calibration month day year and ABC represents the initials of the calibrating technician RCL The RCL Recall command restores the LDC 3900 to the setup state which is in its local memory Bin 0 10 The following criteria are restored when the RCL command is given e The LDC 3900 is in the parameter state which was last stored in that bin The outputs Laser and TEC are both off The bin information includes the LDC 3900 s modular configuration If the LDC 3900 has a different modular configuration than that of the recalled bin the recall 04_10 LDC 3900 Series 55 1 REMOTE OPERATION ere Common Commands and Queries function will not be performed In that case an error E 219 will be generated and the parameter state will not change The syntax for the RCL command is li lt white lt DECIMAL space gt 7 NUMERIC PROGRAM DATA gt where the data value must round off to an integer between 0 and 10 A value of 0 means the recalled state shall be the same as that of a RST command see Table 3 1 on page 45 Up to 11 different stored recall states can be used Ten of these recall states 1 10 are saved by using the SAV command RST The RST Reset command performs a device reset This has the same effect as RCL 0 see Table 3 1 on page 45 but addi
166. ervoltage Category II for transient overvoltages Maximum Relative Humidity lt 80 RH non condensing e Operating temperature range of 0 C to 40 C Storage and transportation temperature of 40 C to 70 C e Maximum altitude 3000 m 9843 ft e 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 about potentially dangerous situations which can result in death injury or damage to the instrument and other components Caution E Earth refer to ground manual Terminal Visible and or invisible laser radiation Alternating current Caution risk Protective of electric Conductor shock Terminal On In position of a bistable push control The or slash I only denotes that mains are on I Caution hot Aa is Terminal Off Out position of a bistable push control or The circle O only denotes that mains are off 0 xii LDC 3900 MIL 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
167. esented listing the commands which are legal for that path All of the LDC 3900 s common commands and queries are listed in Common Commands and Queries on page 48 The lower level remote interface messages are also listed in Chapter 3 Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION BEEP 1 Enables the beeper or beeps once BEEP NONE Returns the enable status of the beeper CHECKSUM NONE Returns a checksum value for the present configuration of parameters DELAY 1 Used to create a delay in the execution of further commands ERR NONE Returns errors generated since the last query up to 10 LAS ALL CALMD 4 Used to set all channels CAL PD monitor responsivity constants 04_10 LDC 3900 Series 75 COMMAND REFERENCE _ LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION LAS ALL CALMD NONE Returns all the channels CAL PD monitor responsivity constants LAS ALL LDI 4 User to set all the channels constant current mode set point values LAS ALL LDI NONE Used to return all the channels constant current source measured values measured about every 600 mS LAS ALL LDV NONE Used to return all the channels measured laser voltage values measured about every 600 mS LAS
168. eter is set to 0 the selected LAS channel will operate in a constant IPD mode when Constant P mode is selected The parameter should be set to 0 for IPD calibration modes Otherwise the value of this parameter is used to convert between IPD and PPD values The units of this parameter are microamps milliwatt In local operation the LASER CALMD value is entered via the CAL PD parameter When the CAL PD parameter is selected LED lit pressing and holding in the PARAMETER SET switch will allow the user to enter the parameter value by adjusting the Adjust Knob Examples LAS CALMD 0 action sets the CAL PD parameter to 0 This enables the constant IPD mode of operation Laser Calmd 1 action sets the CAL PD parameter to 1 00 microamp milliwatt Therefore a photodiode feedback current of 1 microamp will cause the PPD display to read 1 milliwatt LASer CALMD COMMON DEVICE DEPENDENT FRONT PANEL The LASer CALMD query returns the value of the laser s photodiode feedback responsivity CAL PD parameter setting for the selected LAS channel Parameters None The response is an lt nrf value gt Notes If this value is O the selected LAS channel will be set to operate in constant IPD mode and the IPD set point value will be in effect If this value is non zero the selected LAS channel will be set to operate in constant PPD mode and the PPD set point value will be in effect If this value is O the front panel PPD will display and
169. ew C1n value Two Point Calibration Method This procedure will work for any linear temperature sensor The accuracy of this procedure depends on the accuracy of the known temperatures externally measured It is used to determine the zero offset of the device and the gain offset slope 1 LDC 3900 Series Allow the LDC 3900 to warm up for at least one hour Set the SENSOR SELECT switch for the desired sensor type and RECALL the constants for the particular device to be calibrated Select the C1 parameter Read and record the value of C1 Select the C2 parameter Read and record the value of C2 Place the sensor at an accurately known and stable temperature Ta1 Connect the sensor to pins 7 and 8 of the LDC 3900 s 15 pin connector Set the LDC 3900 for normal constant temperature T mode operation Allow the LDC 3900 to stabilize at the known temperature Ta and read the displayed temperature Tg Record these values Repeat Step 3 for another known temperature Ta and the corresponding displayed temperature Tyo MIL Lightwave Two Point Calibration Method cuarren BO The two known temperatures should at the bounds of the intended operating range The smaller the intended operating range the better the calibration over that same range 5 Determine the new value of C1 C1 and C2 C2 from the following calculations First determine the intermediate values U and V where V Tar Taz Ta1 Taz and U Tay
170. example the command TEC Display Set 1 turns the set point display on and TEC Display Set 0 turns the set point display off The words on and off may be substituted in the above example TEC Display Set On turns the set point display on and TEC Display Set Off turns the set point display off For more information on parameter name substitutions see Syntax Diagrams on page 38 LDC 3900 Series 47 REMOTE OPERATION Common Commands and Queries If multiple parameters are expected they should be separated with commas For example to set the Steinhart Hart constants on the LDC 3900 C1 C2 and C3 the following command could be sent TEC CONST 1 111 2 004 0 456 If not all of the parameters need to be changed i e C2 only the other parameters may be omitted as in CONST 2 004 A query has no space between the mnemonic and the question mark as in LAS LDI The LDC 3900 uses a terminator of lt CR gt lt NL gt lt END gt carriage return new line EOI In almost all cases these terminators are automatically inserted by the host user s computer or GPIB driver For more information see lt PROGRAM MESSAGE TERMINATOR gt on page 40 or the IEEE 488 2 standard definition Common Commands and Queries This section contains a list of the common commands and queries which are supported by the LDC 3900 Modular Laser Diode Controller The common commands and
171. f H17EB action enables the TEC status outoff register so that any and all of the above conditions will cause the TEC output to be turned off for the selected TEC channel 04 10 LDC 3900 Series 155 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ENABle OUTOFF COMMON DEVICE DEPENDENT The TEC ENABle OUTOFF query returns the value of the status outoff enable register of the TEC operations things which will turn the TEC output off for the selected TEC channel Parameters None The response is the sum of the following 1 TE Current Limit Condition 256 Sensor Type Change While Output On Event 2 Voltage Limit Condition 512 Output Out of Tolerance Condition 4 N A 1024 Sensor Shorted While Output On Condition 8 High Temperature Limit Condition 2048 N A 16 TEC Interlock Changed Condition 4096 Software Error Condition 32 Booster Changed While Output On Event 8192 N A 64 Sensor Open While Output On Condition 16384 N A 128 Module Open While Output On Condition 32768 N A Notes The enabled TEC outoff events and conditions which can turn the TEC output off can be set by using the TEC ENABle OUTOFF command for the selected TEC channel Examples TEC ENAB OUTOFF response 258 means that a Sensor Type Change Condition or a Voltage Limit Condition will cause the TEC output to be turned off for the selected TEC channel Radix Hex TEC Enab Outoff response H17EB means that all o
172. f the above conditions will cause the TEC output to be turned off for the selected TEC channel Radix Bin TEC Enab Outoff response B1001 means that the High Temperature Limit and TE Current Limit conditions will cause the TEC output to be turned off for the selected TEC channel 156 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC EVEnt COMM DEVICE DEPENDENT The TEC EVEnt query returns the value of the status event register of the TEC operations for the selected TEC channel Parameters None The response is the sum of the following 1 TE Current Limit 256 Sensor Type Changed 2 TE Voltage Limit 512 Output Changed to be In or Out of Tolerance 4 N A 1024 Output On Off Changed 8 High Temperature Limit 2048 New Measurements Taken 16 TEC Interlock Disabled 4096 Calculation Error 32 Booster Changed 8192 Internal TEC Control Communication Error 64 Sensor Open 16384 Software Error in TEC Control 128 TE Module Open 32768 TEC EEPROM Checksum Error Notes The TEC conditions for the selected TEC channel which are reported to the status byte are set via the TEC ENABle EVEnt command The TEC event status is only cleared when the event status is read for the selected TEC channel or a CLS command is issued while the condition status is constantly changing Examples TEC EVE response 513 means that the Output went In or Out of Tolerance and the TE Current L
173. f there is no previously stored message the response will be all spaces MES response Test 3 means the previously stored message was Test 3 Message response This is a test means the previously stored message was This is a test RADix Parameters Notes Examples 128 LDC 3900 Series DEVICE DEPENDENT The RADix command allows the programmer to select the radix type for status condition and event query response data Decimal binary hexadecimal and octal are allowed Character program data is expected as shown above DECimal is the default type Only the first three letters of the words decimal hexadecimal binary or octal are required When the RADIX is selected all status condition and event queries will return values in the new radix In the cases where the radix is not DECimal the flexible numeric type lt nrf value gt as shown in the Command Reference diagrams will be replaced by HEX BIN or OCT representation All of the above radixes may be used to enter program data at any time without the need for issuing the RADix command The proper prefix must also be used with Hex H binary B or octal 0 This command may be useful for setting up status reporting blocks The bit wise status representation may be more easily read in BIN HEX or OCT RAD dec action the decimal radix is selected rad hex ESR action the hexadecimal radix is selected response H80
174. for commands with the LDC 3900 Modular Laser Diode Controller TEC MODE 3t TEC T 25 TEC Const 1 2 3 5 TEC IOUT 1 STEC DIS l tecisetit Laser limit ldi 400 LAS display ldi The following are examples of invalid syntax for the LDC 3900 Modular Laser Diode Controller These command strings would produce an erroneous result as explained TEC MODE T Missing colon Mode expected TEC MODE R DEC Missing semicolon DEC command generates an error LAS DIS Space not allowed before question mark DIS command expected Las LDI33 dis Space missing between LDI command and the parameter value 33 Note The LAS CHAN n and TEC CHAN n commands must be used to switch adjustment to a new channel where n is the number of the desired channel Once a channel is selected for TEC adjustment all of the subsequent TEC commands will effect that channel only and likewise for the LAS channel adjustment and subsequent LAS commands Using Commands with Parameters Some commands expect a parameter For example if the temperature set point is to be entered the command could be TEC T 30 This would set the LDC 3900 s selected TEC module set point temperature to 30 C If a single parameter is expected it should follow the command with at least one space between the command and the parameter The nominal value for on off parameters is 1 on O off For
175. for channels 3 and 4 are set to 30 TEC ALL ITE DEVICE DEPENDENT The TEC ALL ITE command sets the TEC control current set point for all channels in ascending order Parameters Four lt nrf value gt s which represents the ITE set point currents for the all channels in Amps The parameter data corresponds to each channel in ascending order Notes These set points are used by the TECs constant ITE mode only on the corresponding channels Examples TEC ALL ITE 1 1 1 1 action sets the TEC output current set point to 1 000 Amps for all channels TEC ALL MODE ITE Tec All Ite 3 5 2 2 2 action sets the TEC output current set point to 3 500 Amps for channel 1 2 000 Amps for channels 2 4 and the outputs are controlled to those values if the corresponding TEC output is on 132 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL ITE DEVICE DEPENDENT The TEC ALL ITE query returns the values of the measured TEC output current for all channels in ascending order Parameters None The response values represents the measured ITE current in Amps The responses are separated by commas and correspond to each channel in ascending order Notes The TEC load current is constantly measured and updated regardless of the TEC mode of operation The measurements are updated approximately once every 600 msec per channel If an external booster is used the given ITE measurement w
176. form of the Laser Parameter selections Refer to Figure 2 13 on page 15 for the discussion of the Laser Parameter features TEC GI PARAMETER GD LASER LIMI TE LIM I LIMT HI LIM P SELECT CONST 7 CAL PD GAIN RECALL SET SAVE Figure 2 22 LDC 3900 Laser Parameter Section Laser Parameter Select The Parameter Select switch is used to enter this Select mode While the Adjust Laser Indicator is orange Laser mode selected press the Parameter Select switch to enter this mode When the Laser Parameter Select mode is first entered the LIM Indicator becomes lit and the unit displays the current limit value in mA All LED indicators in the Laser Display switch section are turned off If the Parameter Select switch is released this state continues for three seconds after which the unit reverts to its former state If the Parameter Select switch is pressed repeatedly successive Laser parameter values are displayed and the appropriate Laser Parameter Indicator LED becomes lit The order of cycling through the Laser parameter list is LIM I LIM P CAL PD then back to LIM I and so on 28 LDC 3900 Series im IL Lightwave 04 10 OPERATION LDC 3900 Front Panel Laser Parameter Set The Parameter Set switch is used to enter Set mode where parameter values may be edited and are then stored
177. g Table 1 1 LDC 3900 Options DESCRIPTION MODEL NUMBER 100 mA Current Source Module 39010 200 mA Current Source Module 39020 500 mA Current Source Module 39050 1 Amp Current Source Module 39100 4 Amp Current Source Module 39400 4 Amp Current Source Module 39400M 8 Amp Current Source Module 39800 32 Watt TEC Module 390322 Combination Module 200 mA Current Source and 8 Watt TEC 394202 Combination Module 500 mA Current Source and 12 Watt TEC 39425 Combination Module 500 mA Current Source and 12 Watt TEC with modulation 39427 1 Model 39400M is available for driving SDL 5760 MOPA laser amplifier section includes drive for fan and LED on indicator 2 Includes ILX model 510 calibrated 10 k Ohm thermistor Table 1 2 LDC 3900 Options and Accessories DESCRIPTION MODEL NUMBER Combination Module 1000 mA Current Source and 12 Watt TEC with modulation 39437 Combination Module 2000 mA Current Source and 8 Watt TEC 39440 Rack mount flange kit enables installation into a standard 19 inch wide rack 103 Temperature Controlled Laser Diode Mount 4407 Temperature Controlled Laser Diode Mount available with collimating assembly 4412 High Power Laser Diode Mount 4442 CW Filter Cable included with Current Source Modules 320 Current Source Interconnect Cable unterminated 301 Current Source Laser Diode Mount Interconnect Cable 303 TEC Interconnect Cable unterminated 501 TE
178. gt Although the status of the switch is on the selected TEC output may not have reached the set point value With a LAS TEC combination module a response of 1 indicates that the output switch is enabled Either the TEC or LAS output or both may be on In local operation the status of the TEC output is determined by visually inspecting the indicator LED of the ON switch in the TEC MODE area of the front panel lit ON With combination modules when only the TEC or LAS output is on the corresponding output LED will blink Tec Out response 0 means the selected TEC s OUTPUT switch is off TEC output is off TEC OUT response 1 means the selected TEC s OUTPUT switch is on TEC output is on MIX Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC R Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The TEC R command sets the TEC s constant thermistor resistance or linear sensor reference set point for the selected TEC channel An lt nrf value gt which represents the thermistor or RTD resistance set point value in KQ the AD590 current set point in mA or the LM335 voltage set point in mV depending on the selected sensor type The R set point is used to control the TEC output in R mode only Using the R mode the user may also monitor the temperature of the TEC load via a remote algorithm of his her own design If an entered value is greater than 450 an error E222 will be genera
179. gt new line lt END gt EOI terminator is selected The LDC 3900 will terminate a message with the lt NL gt lt END gt characters in succession and in that order MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TERM Parameters Notes Examples DEVICE DEPENDENT RONT PANEL The TERM query allows the programmer to determine which program message terminator is currently selected lt CR gt carriage return lt CR gt lt NL gt new line lt CR gt lt END gt EOI lt CR gt lt NL gt lt END gt lt NL gt lt END gt lt NL gt and lt END gt are allowed None The response will be one of the following 0 lt CR gt lt NL gt lt END gt 1 lt CR gt lt NL gt 2 lt CR gt lt END gt 3 lt CR gt 4 lt NL gt lt ENDs gt 5 lt NL gt 6 lt END gt and 7 N A lt CR gt lt NL gt lt END gt 0 is the default type Term response 0 means the selected program message terminator is the lt CR gt lt NL gt lt END gt characters in succession in that order TERM response 2 means the selected program message terminator is the lt CR gt lt END gt characters in succession and in that order TIME Parameters Notes Examples 04 10 DEVICE DEPENDENT RONT PANEL The TIME query allows the programmer to determine how much time has passed since the LDC 3900 was last powered up None The response will be character data
180. h uses both the TEC and Laser controller of the LDC 3900 to gather L I data at varying temperatures TEC Step and Delay Example Program The following BASIC programming example Example Program 4 1 exercises the TEC controller of the LDC 3900 and it demonstrates the DELAY and TEC STEP commands This example assumes that a LDC 3900 s Laser module is set up for measuring laser light power It also assumes the use of a subroutine for talking to the LDC 3900 over the GPIB This subroutine is shown in Example Program 4 3 100 CMDS Tec Chan 1 GOSUB 1000 Set the TEC channel 200 CMDS Tec Const 1 125 2 347 0 855 GOSUB 1000 Set constants for typical 10K thermistor 210 CMDS Tec Gain 10 GOSUB 1000 Set control loop gain 220 CMDS Tec Step 100 Tec Mode T GOSUB 1000 Temperature mode with 10xC step 230 CMDS Tec T 0 Output ON GOSUB 1000 Start laser temperature at 0xC 240 FOR X 1 TO 10 Step temperature from 0 to 100 xC 250 CMDS Delay 20000 Las MDP Tec Inc GOSUB 1000 Wait 20 seconds for temperature to 260 INPUT 2 PS stabilize measure laser light power 270 and increment laser temp by 10xC 280 NEXT X Laser Constant Power Mode Example Program The following BASIC programming example exercises the Laser controller of the LDC 3900 and it demonstrates the use of the LAS CALMD LAS Mode MDP and LAS MDP commands for working in constant optical power mode 04
181. hat the LDC 3900 Modular Laser Diode Controller is ready for a value to be entered during the calibration cycle of the LASer CAL LDI mode for the selected LAS channel Parameters None The response will be either 1 ready or O not ready Notes After this query is issued and a response of 1 is received the LDC 3900 Modular Laser Diode Controller will be ready for the user to enter a current value via the LASer LDI command see the Calibration section of the LASER module instruction manual In local operation the ready state during the calibration cycle is indicated by a beep if the beeper is enabled which is issued by the LDC 3900 Modular Laser Diode Controller when it is ready for a value to be entered Examples LASer CAL LDI response 1 means the LDC 3900 Modular Laser Diode Controller is ready for the user to enter a current value via the LASer LDI command LASer Cal Ldl response 0 means the LDC 3900 Modular Laser Diode Controller is not yet ready for the user to enter a LASER current value LASer CAL LDV C DEVICE DEPENDENT The LASer CAL LDV command is used to enter the LASER voltage measurement calibration mode for the selected LAS channel Parameters None Notes After this command is issued the LDC 3900 Modular Laser Diode Controller will allow calibration of the laser voltage measurement This procedure is outlined in the Calibration section of the LASER module instruction manual The LASer CAL LDV query may b
182. he OPC query is OPRAH PO PSC The Power on Status Clear command controls the automatic power on clearing of the Service Request Enable Register the Standard Event Status Enable Register the Event Status Enable Register the Condition Status Enable Register and the Parallel Poll Enable Register The syntax for this command is lt white lt DECIMAL space gt NUMERIC PROGRAM DATA gt where the data is a Boolean value 0 Power on status clear flag is set FALSE therefore allowing SRQ interrupts after power on 1 Power on status clear flag is set TRUE therefore clearing all enable registers and disallowing SRQ interrupts to be asserted after power on When the PSC 1 command is sent the LDC 3900 will clear the above mentioned enable registers set them all to 0 at power up This may be done to avoid any undesirable service requests after a power on off cycle of the LDC 3900 Modular Laser Diode Controller The factory default value for this bit is 0 Power on Status Clear is disabled Therefore the values of the enable registers are restored from their condition at the last power down when a power up occurs LDC 3900 Series 53 a REMOTE OPERATION 3 Common Commands and Queries PSC The Power on Status Clear Query allows the programmer to query the LDC 3900 Modular Laser Diode Controller s power on status clear flag A response of 0 means that the Standard Event Status Enable Register Se
183. hown in Figure 3 9 on page 50 The contents of these two registers is logically ANDed then the bits are ORed to get the Event Summary Bit message 04 10 LDC 3900 Series 49 1 REMOTE OPERATION _ Common Commands and Queries The syntax for the ESE command is 00 space gt NUMERIC gt PROGRAM DATA gt Standard Event Status Register Logical OR Standard Event Status Enable Register Figure 3 9 Standard Event Status Register Standard Event Status Enable Register Bit Reference 0 Operation Complete 4 Execution Error 1 N A 5 Command Error 2 Query Error 6 N A 3 Device Dependent Error 7 Power On Setting bit O allows the user to poll or generate SRQ from any overlapped commands after any previous operations are completed This may be useful for ensuring that an operation such as Output on is complete before a measurement is made Although this could be performed without using service requests an 50 LDC 3900 Series im IL Lightwave REMOTE OPERATION Common Commands and Queries interrupt driven program makes more efficient use of the GPIB than polling or waiting WAI routines See also Operation Complete Definition on page 66 ESE This query will cause the LDC 3900 to return the value of the Standard Event Enable Register This allows the user to determine which status bits can set the summary bit bit 5 in the status byte register
184. ich have been summarized and reported to the Status Byte Register which is read via the STB query Parameters None The response is the sum of the following 1 N A 4 LASER Event Status Register Summary 2 N A 8 LASER Condition Status Register Summary Notes If the Status Byte Register is read via the STB and a LASER condition or event is summarized in bits 3 or 2 any or all of the enabled LASER channels may have been responsible The LAS STB may then be used to poll each of the LASER channels to determine which channel s summarized conditions or events have been reported Examples Las STB response 4 means the selected LASER channel s event register caused summary bit 2 of the Status Byte Register to be set LAS STB response 12 means the selected LASER channel s condition and event registers caused summary bits 3 and 2 of the Status Byte Register to be set LAS STB response O means the selected LASER channel s condition and event registers did not cause summary bits 3 or 2 of the Status Byte Register to be set 04 10 LDC 3900 Series 125 126 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer STEP Parameters Notes Examples DEVICE DEPENDENT The LASer STEP command is used to increment or decrement the selected laser control mode set point by the given amount when used with the LASer INC or LASer DEC command An integer value of the step amount in the range 1 to 9999 The step of 1 co
185. ies 135 136 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL MODE ITE DEVICE DEPENDENT The TEC ALL MODE ITE command selects TEC constant TE current mode for all channels These commands effect all channels regardless of the TEC channel selection Parameters None Notes This mode keeps the TEC current constant regardless of load temperature variations on the selected TEC channel Changing modes causes the corresponding TEC output to be forced off Examples TEC ALL MODE ITE action sets the TEC controller for constant TEC current operation for all channels TEC ALL MODE R COMMON DEVICE DEPENDENT The TEC ALL MODE R command selects TEC constant thermistor resistance linear sensor reference mode for all channels Parameters None Notes Since sensor resistance or linear sensor reference is a function of temperature this mode also controls the TEC output load temperature but it bypasses the use of the conversion constants for set point calculation This allows finer control of temperature in cases where the sensor s temperature model and therefore the constants is not known Changing modes causes the corresponding TEC s output to be forced off Examples TEC ALL MODE R action sets the TEC controller for constant thermistor resistance linear sensor reference operating mode for all channels TEC ALL MODE T Co DEVICE DEPENDENT The TEC ALL MODE T command selects TEC constant temperature
186. ill remain zero as the internal output section is disabled in that case for the given channel Examples TEC ALL ITE response 2 43 2 44 0 0 0 0 means the measured TEC output current is 2 430 Amps for channel 1 2 440 Amps for channel 2 and 0 0 Amps for channels 3 and 4 Tec All lte response 3 27 0 0 0 54 1 203 means the measured TEC output current is 3 270 Amps for channel 1 0 0 Amps for channel 2 0 540 Amps for channel 3 and 1 203 Amps for channel 4 TEC ALL LIMit DEVICE DEPENDENT The TEC ALL LIMit command path is used to get to the global TEC limit commands for all channels The following commands may be reached directly from the TEC ALL LIMit command path TEC ALL LIMit ITE TEC ALL LIMit ITE TEC ALL LIMit THI TEC ALL LIMit THI TEC ALL LIMit ITE COMMON DEVICE DEPENDENT The TEC ALL LIMit ITE command sets the TEC TE current limit value for all channels Parameters Four lt nrf value gt s representing the limit value of the TE current in Amps for each TEC channel in ascending order Notes These values also limit the TEC booster of the corresponding channel output signal voltage to a value which is proportional to the TEC limit current approximately 1 V A If the new limit value is lower than the present ITE set point the ITE set point will be forced down to the value of the ITE limit and an E434 error will be generated Examples TEC ALL LIM ITE 3 5 3 5 1 5 1 5 action the TEC current
187. imit events have occurred for the selected TEC channel since the last TEC EVEnt query Radix Hex TEC Event response H82 means that the Voltage Limit and TE Module Open events have occurred for the selected TEC channel since the last TEC EVEnt query TEC GAIN Co DEVICE DEPENDENT FRONT PANEL The TEC GAIN command sets the TEC control loop gain for the selected TEC channel Parameters An lt nrf value gt between 1 300 the value will be stored to the nearest of 1 3 10 30 100 or 300 for the selected TEC channel Notes If the user enters a gain value which is greater than 300 a value of 300 will be stored If the user enters a gain value which is less than 1 a value of 1 will be stored If the user enters a value which is not legal the LDC 3900 will round that value to the nearest legal value if possible In local operation the gain is entered by selecting the GAIN parameter pressing and holding in the SET switch and entering the desired value by adjusting the front panel knob When the SET switch is released the gain value is stored in non volatile memory Examples TEC GAIN 100 action the TEC control loop gain for the selected TEC channel is set to 100 Tec gain 3 action the TEC control loop gain for the selected TEC channel is set to 3 TEC Gain 200 action the TEC control loop gain for the selected TEC channel is set to 100 the LDC 3900 rounds 200 to the nearest valid number 04_10 LDC 3900 Series
188. in number The bin number is shown on the TEC display as a number in the range 0 10 Bin O is reserved for the reset default parameters If the Parameter Set switch is pressed while the unit is in this Select mode then the unit will enter Set mode While the Parameter Set switch is pressed the selected bin number can be changed by rotating the Adjust Knob The new value is accepted when Parameter Set switch is released When a parameter setup is saved the LDC 3900 modular system configuration is also saved in the bin Therefore if a bin is to be recalled the LDC 3900 must have the same configuration If the present configuration is different than the saved configuration the LDC 3900 will not perform the Recall function Instead an error of E 219 will be generated 32 LDC 3900 Series MIL Lightwave OPERATION Rear Panel Controls and Connections Rear Panel Controls and Connections Refer to Figure 2 25 on page 33 for identification of rear panel controls and connectors The section briefly describes the back panel connectors of the LDC 3900 mainframe See the module instruction manuals for the description of the module back panels A CAUTION There are no user serviceable parts in the instrument including the external fuses in the AC power entry module Contact ILX Customer Service see Comments Suggestions and Problems on page xv for contact information for information about servicing the instrument
189. in the form hours minutes seconds The TIME clock is independent of the TIMER clock Time response 1 02 36 means that 1 minute and 2 36 seconds have passed since the LDC 3900 was powered up TIME response 32 00 76 means that 32 minutes and 0 76 seconds have passed since the LDC 3900 was powered up LDC 3900 Series 173 COMMAND REFERENCE LDC 3900 Device Dependent Commands TIMER DEVICE DEPENDENT The TIMER query allows the programmer to determine how much time has passed since the last TIMER query was issued Parameters None The response will character data which represents hours minutes seconds Notes Each time the TIMER query is issued the timer is reset to 0 and the elapsed time since the last TIMER query is returned The timer counter is initially set at power up the same as the TIME counter So the first time the TIMER is issued its response will be the same as if a TIME query s response Examples Timer response 00 02 00 31 means the LDC 3900 has been on for 2 minutes and 0 31 seconds since the last TIMER query was issued TIMER response 00 00 12 03 means the LDC 3900 has been on for 12 03 seconds since the last TIMER query was issued Error Messages Error messages may appear on the TEC or Laser displays when error conditions occur in the respective functions of the LDC 3900 For example a current limit error ina TEC module of the LDC 3900 will be displayed on the TEC display
190. ing 1 LASER Current Limit 256 Output is Shorted 2 LASER Voltage Limit 512 Output Changed to be In Out of Tolerance 4 N A 1024 Output On Off State Changed 8 Power Limit 2048 New Measurements Taken 16 Interlock Disabled 4096 Calculation Error 32 N A 8192 Error Communicating LASER Board 64 N A 16384 Software Error in LASER Control 128 Open Circuit 32768 LASER EEPROM Checksum Error Notes The selected channel s LASER conditions that are reported in the status byte can be set by using the LASer ENABle EVEnt command The LASER event status is only cleared when the event status is read or by the CLS command while the condition status is constantly changing Examples LAS EVE response 513 means that the selected channel s LASER output tolerance changed and current limit events have occurred since the last LASer EVEnt query Radix Hex Laser Event response H88 means that the selected channel s LASER Power limit and Open circuit events have occurred since the last LASer EVEnt query 114 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer INC DEVICE DEPENDENT The LASer INC command increments the present LAS channel s selected laser control mode set point by one or more steps Optional parameters allow multiple steps to be incremented and the time in milliseconds between increments to be set respectively Parameters None 1 or 2 Notes The i
191. instrument including the external fuses in the AC power entry module Contact ILX Customer Service see Comments Suggestions and Problems on page xv for contact information for information about servicing the instrument Line Voltage Selection Line voltage selection is made by rotating the line voltage selector insert The line voltage selector insert is located inside the power entry module cover To open this cover turn the slot slightly with a screwdriver The cover will pop out exposing the voltage selector insert Pull out the selector insert turn it until the desired voltage selection appears and re insert it into the power entry module 04_10 LDC 3900 Series INTRODUCTION AND SPECIFICATIONS Product Overview 4 LDC 3900 Series MIL Lightwave CHAPTER 2 OPERATION 5 B E a t8 a a El E E E E E E a E a This chapter describes how to install adjust and operate the LDC 3900 Modular Laser Diode Controller It is divided into several sections covering installation familiarization and adjustment warm up and environmental considerations and normal operating procedures The section titled LDC 3900 Front Panel on page 9 gives an overview of the LDC 3900 Modular Laser Diode Controller s front panel features and it presents a guide to quickly familiarize the user with the front panel operations Installation General installation procedures and considerations are covered in the following pages Module installation and
192. l separated by commas IHBW mode is the same as mode low bandwidth except that the output low bandpass filter is disabled in IHBW mode LAS ALL MODE response llow Ihbw llbw Ilbw means that constant current mode is in effect for the laser output of channels 1 3 and 4 Channel 2 is in constant current high bandwidth mode Laser ALL MODE response Ihbw P P P means that constant IHBW current high bandwidth mode is in effect for the laser output of channel 1 Constant power P mode is in effect for channels 2 4 LASer ALL MODE LDC 3900 Series DEVICE DEPENDENT The LASer ALL MODE command path is used to get to the global laser mode selection commands These commands effect all channels regardless of the LAS channel selection The following commands may be reached directly from the LASer ALL MODE command path LASer ALL MODE IHBW LASer ALL MODE ILBW LASer ALL MODE MDP MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL MODE IHBW COMM DEVICE DEPENDENT The LASer ALL MODE IHBW command selects laser high bandwidth constant current mode for all channels Parameters None Notes This command sets the Ihbw mode for all four channels at once Examples las all mode ihbw action enables the laser high bandwidth constant current mode on all channels LASer ALL MODE ILBW COMMC DEVICE DEPENDENT The LASer ALL MODE ILBW command selects laser low bandwidth cons
193. l the output is stable within tolerance before performing further operations but it is not necessary When the LASER output is off it is safe to connect or disconnect devices to the LASER output terminals When aLASER output is off an internal short is placed across the output terminals If this occurs for the selected LAS channel it causes the OUTPUT SHORTED light to come on Las All Only Out 1 1 0 1 action turns the laser output off on channel 3 and turns the laser outputs on for channels 1 2 and 4 TEC output on all channels is not effected LAS ALL only OUT 1 1 1 1 action turns the laser output on for all channels the TEC output on all channels is not effected LASer ALL OUTput Parameters Notes Examples DEVICE DEPENDENT The LASer ALL OUTput command turns the laser output on or off for each channel Four lt nrf value gt s one for each channel in ascending order 1 non zero on O off After a channel s output is turned on it may be useful to wait until the output is stable within tolerance before performing further operations but it is not necessary When the LASER output is off it is safe to connect or disconnect devices to the LASER output terminals When aLASER output is off an internal short is placed across the output terminals If this occurs for the selected LAS channel it causes the OUTPUT SHORTED light to come on Las All Out 0 1 0 1 action turns the laser output off on channels 1 an
194. lected channel s LASer TOLerance command With v3 5 and above if the selected LAS channel is operated in P mode the current tolerance parameter is not used unless CAL PD 0 WARNING If the tolerance is set too tight it may never be achieved This is due to the calibration of the set point and measurement values Examples Las Tol 0 5 10 action the selected LAS channel s LASER current source will be in tolerance when the LASER current is within 0 5 mA for 10 000 seconds LAS TOL 1 1 5 LAS LDI 30 WAI LAS LDI action the selected LAS channel s LASER current source will return a current measurement after it has reached tolerance where the LASER current is within 1 0 mA of 30 0 mA for 1 500 seconds LASer TOLerance C DEVICE DEPENDENT The LASer TOLerance query allows the programmer to determine how the selected channel s LASER current tolerance is set Parameters None The response consists of two data units the first for the current tolerance in mA and the second for the time window in seconds Notes The tolerance of the selected LAS channel LASER current may be used to delay programming after an LASer OUTput 1 command is issued or the set point is changed A change of the output into or out of tolerance flag sets a flag in the LASER status event register and so entering or exiting LASER current tolerance may be used to generate service requests Examples Las Tol response 0 2 5 0 means the selected LAS channel has a
195. lecting the LIM parameter and visually reading the LASER display Examples LAS LIM 1 response 40 means the selected channel s laser current limit is 40 mA Laser LIM 1 response 300 means the selected channel s laser current limit is 300 mA LASer LIMit MDP Co DEVICE DEPENDENT FRONT PANEL The LASer LIMit MDP command sets the laser monitor photodiode power limit value Parameters An lt nrf value gt which represents the selected channel s laser monitor photodiode power limit in mW Notes When constant MDP mode is used the selected channel s output is limited only by the LIM I value The LIM MDP condition may be used to shut the selected channel s LASER output off but this requires the use of the LASer ENABle OUTOFF command to set bit 3 of the LASER OUTOFF ENABLE register In local operation the limit power is entered by selecting the LIM P parameter adjusting the Adjust Knob until the desired value is displayed and then pressing the SET switch in the PARAMETER area of the front panel Examples LAS LIM MDP 10 action sets the selected channel s laser output power limit to a value which corresponds to producing 10 00 mW of PD feedback optical power Las Limit MDp 5 action sets the selected channel s laser output power limit to a value which corresponds to producing 5 00 mW of PD feedback optical power 04_10 LDC 3900 Series 117 118 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASe
196. lly reading the value on the TEC display Appendices A B and C contain information on the use of these constants with the various sensor types Examples TEC CONST response 1 111 2 03 0 85 means C1 1 111 C2 2 030 and C3 0 850 for the selected TEC channel TEC Const response 1 00 2 222 0 07 means C1 1 000 C2 2 222 and C3 0 070 for the selected TEC channel TEC DEC DEVICE DEPENDENT The TEC DEC command decrements the selected control mode set point by one step Parameters None Notes The decremental amount is one step The step size for the selected channel can be edited via the STEP command its default value is 0 1 C 1 mA ITE 1 W THERM 0 01 mA AD590 0 1 mV LM335 or 0 01 W RTD depending on the mode of operation Examples TEC MODE T TEC STEP 2 TEC DEC action The mode is set on the selected TEC channel for constant temperature and the set point is decremented by 0 2 C TEC Mode r Tec STEP 20 Tec Dec action The mode is set on the selected TEC channel for constant resistance and the set point is decremented by 20 0 02 K W assuming that the SENSOR SELECT switch is in the THERM position TEC DISplay DEVICE DEPENDENT The TEC DISplay command enables or disables turns off the TEC display and TEC section s indicator LEDs Parameters An lt nrf value gt 1 on O off Notes Turning the TEC display and LEDs off means that a message of all blank spaces is sent to the TEC
197. local operation the R measured value is determined by pressing the R switch in the TEC DISPLAY area of the front panel and visually reading the value on the TEC display TEC R response 10 543 means the measured TEC thermistor or RTD resistance is 10 543 kQ or the measured AD590 current is 10 543 mA or the measured LM335 voltage is 10 543 mV depending on the SENSOR SELECT switch position Tec R response 0 128 means the measured TEC thermistor or RTD resistance is 128 Q or the measured AD590 current is 0 128 mA or the measured LM335 voltage is 0 128 V depending on the SENSOR SELECT switch position LDC 3900 Series 165 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC SENsor DEVICE DEPENDENT The TEC SENsor query is used to read back the SENSOR SELECT and THERM SELECT switch position value for the selected TEC channel This value is a coded representation of the sensor type thermistor sensor current Parameters None The response value of 1 thermistor at 100 mA 2 thermistor at 10 mA 3 LM335 sensor 4 AD590 sensor 5 RTD Notes The sensor code for the selected TEC channel is displayed on the TEC display and bit 8 of the TEC event register is set whenever the back panel SENSOR SELECT switch position is changed The sensor selection must be made locally at the back panel SENSOR SELECT and THERM SELECT switches In local operation the setting of the SENSOR SELECT and THERM SELECT switche
198. lowing 1 TE Current Limit 256 N A 2 Voltage Limit Error 512 Output Changed to be In Out of Tolerance 4 N A 1024 Output On Off Changed 8 High Temperature Limit 2048 New Measurements Taken 16 TEC Interlock Disabled 4096 Calculation Error 32 Booster Enable 8192 Internal Communication Error with TEC Board 64 Sensor Open 16384 Software Error 128 TE Module Open 32768 TEC EEPROM Checksum Error Notes The enabled TEC events for the selected TEC channel can be set by using the TEC ENABle EVEnt command The TEC event status for the selected TEC channel can be read and reset by issuing the TEC EVEnt query Examples TEC ENAB EVE response 520 means that the High Temperature Limit and Output Out of Tolerance TEC events for the selected TEC channel will be reported in summarized form to the status byte register bit 0 Radix Hex TEC Enab Eve response HFFFB means that all of the above events for the selected TEC channel will be reported in summarized form to the status byte register bit 0 154 LDC 3900 Series MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ENABle OUTOFF COMMON DEVICE DEPENDENT The TEC ENABle OUTOFF command sets the status outoff enable register of the TEC operations things which will turn the TEC output off for the selected TEC channel Parameters An lt nrf value gt whose sum represents the enabled bits 1 TE Current Limit Condition 25
199. lues at power up as they were at power down unless the power on status clear flag is set true see PSC Chapter 3 LAS ENAB EVENT 136 action enables the selected channel s LASER status event register so that the Open circuit and Power limit events will be reported in summarized form to the status byte bit 2 Laser Enable Event HFF9B action enables the selected channel s LASER status event register so all of the above events will be reported in summarized form to the status byte bit 2 MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ENABle EVEnt Commc DEVICE DEPENDENT RONT PANEL The LASer ENABle EVEnt query returns the value of the selected channel s status event enable register of the LASER operations Parameters None The response is the sum of the following 1 LASER Current Limit256 Output is Shorted 2 LASER Voltage Limit512 Output Changed to be In Out of Tolerance 4 N A 1024 Output On Off State Changed 8 Power Limit 2048 New Measurements Taken 16 Interlock State Changed4096 Calculation Error 32 N A 8192 Error Communicating LASER Board 64 N A 16384 Software Error in LASER Control 128 Open Circuit32768 LASER EEPROM Checksum Error Notes The enabled LASER events for the selected LAS channel can be set by using the LASer ENABle EVEnt command The selected channel s LASER event status can be monitored by the LASer EVEnt query Examples LAS ENAB EVE
200. mally possible to exceed this range However if the GPIB address were to exceed 30 it will not hang up the bus If the GPIB address is ever displayed as a value greater than 30 service of the LDC 3900 Modular Laser Diode Controller would be required since this value is normally limited by the LDC 3900 Modular Laser Diode Controller s firmware Extended GPIB addressing is not implemented on the LDC 3900 Modular Laser Diode Controller at this time ANSI IEEE 488 2 Definitions The following sections contain the relevant definitions for syntax diagrams and syntax elements for the LDC 3900 Modular Laser Diode Controller commands as defined by the IEEE 488 2 standard A complete listing of that standard is not practical here but these definitions are applicable to the remote operation of the LDC 3900 Modular Laser Diode Controller Syntax Diagrams The syntax diagrams show the most complete form of command construction but they don t show every possible construction Some of the other possibilities which are not shown in the syntax diagrams are discussed in Advanced Programming 38 LDC 3900 Series im IL Lightwave REMOTE OPERATION ANSI IEEE 488 2 Definitions on page 61 These syntax diagrams conform to the ANSI IEEE 488 2 1987 standard and the terminology presented here reflects that standard The oval or round shape contains a terminal syntactic element These represent a basic function such as a single ASCII character which c
201. mented a total of 0 9 mA after 10 seconds LAS STEP 1 LAS Mode MdP Las Out On Las INC action The selected channel s power set point is incremented by 1 0 mW with the output on LASer LDI Co DEVICE DEPENDENT FRONT PANEL The LASer LDI command sets the laser control current for the selected LAS channel Parameters An lt nrf value gt which represents the laser output current in mA Notes Set point is the same for both low and high bandwidth output modes on the selected channel In local mode ADJUST LAS switch would select the desired LAS channel Then the LASER switch in the LASER DISPLAY area of the front panel would be pressed Then the desired value would be entered via the Adjust Knob and the LASER DISPLAY SET switch pressed Examples Las LDI 400 action sets the selected channel s laser output current to 400 00 mA LAS Idi 1000 action sets the selected channel s laser output current to 1000 00 mA 04_10 LDC 3900 Series 115 116 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer LDI DEVICE DEPENDENT FRONT PANEL The LASer LDI query returns the value of the measured laser current for the selected LAS channel LDC 3900 Series Parameters None The response is an lt nrf value gt Notes Response is the selected channel s measured laser output current for either low or high bandwidth modes This measurement is updated approximately once every 600 mSec In local mod
202. meters TEC ALL ITE 4 Used to set all the channels TEC current ITE set points TEC ALL ITE NONE Returns all the channels measured TEC current ITE values measured about every 600 msec TEC ALL LIM ITE 4 Used to set all the channels TEC constant current source limit values TEC ALL LIM ITE NONE Used to return all the channels constant current source limit values TEC ALL LIM THI 4 Used to set all the channels TEC upper temperature limit values TEC ALL LIM THI NONE Returns all the channels TEC upper temperature limit values TEC ALL MODE NONE Returns all the channels modes ITE TEC current R resistance reference or T temperature TEC ALL MODE ITE NONE Sets all the TEC channels to constant TEC current mode TEC ALL MODE R NONE Sets all the TEC channels to constant thermistor resistance linear sensor reference mode TEC ALL MODE T NONE Sets all the TEC channels to constant Temperature mode LDC 3900 Series 79 COMMAND REFERENCE _ LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary NUMBER OF NAME PARAMETERS EXPECTED FUNCTION TEC ALL ONLY OUT 4 Sets all the TEC channels outputs only on or off Useful with combination modules TEC ALL OUT 4 Same action as setting all the TEC channels OUTPUT switch on off TEC ALL OUT NONE Returns the OUTPUT switch status for all
203. mmand A lt PROGRAM MESSAGE TERMINATOR gt causes the next command search to begin at the root node A leading colon on a lt PROGRAM MESSAGE UNIT gt will cause the LDC 3900 to begin searching for the command at the root node Otherwise after a semicolon the LDC 3900 will first search the most recently used node for the command It will continue to search the command tree until it finds a legal command path by searching each previously used node up to the root If no legal path is found the LDC 3900 will generate an error message For more information on creating and using LDC 3900 commands see Advanced Programming on page 61 LDC 3900 Series 43 REMOTE OPERATION _ ANSI IEEE 488 2 Definitions lt PROGRAM DATA gt Parameters Parameters and other lt PROGRAM DATA gt may be entered after a command in a lt PROGRAM MESSAGE UNIT gt The lt COMMAND PROGRAM HEADER gt command and first lt PROGRAM DATA UNIT gt parameter must be separated by a lt PROGRAM HEADER SEPARATOR gt white space see White Space on page 39 lt ARBITRARY BLOCK PROGRAM DATA gt This element allows any 8 bit bytes including extended ASCII to be transmitted in a message The syntax for an lt ARBITRARY BLOCK PROGRAM DATA gt element is lt digit gt Figure 3 7 lt ARBITRARY BLOCK PROGRAM DATA gt Syntax Diagram where a non zero digit is defined as a single ASCII encoded byte in the range
204. mode low bandwidth Laser Mode ilbw action sets the selected channel s laser output for constant mode low bandwidth LASer MODE MDP DEVICE DEPENDENT FRONT PANEL The LASer MODE MDP command selects laser constant power mode for the present LAS channel Parameters None Notes This mode of laser operation requires the selected channel s laser s monitor PD feedback to maintain constant optical power or constant monitor current In this mode the displayed parameter will be either IPD if CALMD 0 in mA or PPD if CALMD gt 0 in mw In local operation the constant MDP mode is selected by pressing the LASER MODE SELECT switch until the P indicator is lit Examples LAS MODE MDP action sets the selected channel s laser output mode of operation to constant optical power mode Laser Mode MDp action sets the selected channel s laser output mode of operation to constant optical power mode LASer ONLY DEVICE DEPENDENT The LASer ONLY command path is used to get to the laser only commands The following commands may be reached directly from the LASer ONLY command path LASer ONLY OUTput 04_10 LDC 3900 Series 121 122 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ONLY OUTput DEVICE DEPENDENT The LASer ONLY OUTput command turns the laser output only on or off for the selected channel LDC 3900 Series Parameters An lt nrf value gt 1 non zero on O off
205. mode for all channels Parameters None Notes Since TEC load temperature is derived from sensor resistance reference constant R and T modes are related In T mode the set point is converted to resistance or reference using the appropriate constants and conversion model Changing modes causes the corresponding TEC channel s output to be forced off Examples TEC All MODE T action sets the TEC controller for constant load temperature operating mode for all channels TEC ALL ONLY LDC 3900 Series DEVICE DEPENDENT The TEC ALL ONLY command path is used to get to the global TEC only commands These commands effect all channels regardless of the TEC channel selection The following commands may be reached directly from the TEC ALL ONLY command path TEC ALL ONLY OUTput MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL ONLY OUTput DEVICE DEPENDENT The TEC ALL ONLY OUTput command turns the TEC output only on or off for each channel Parameters Four lt nrf value gt s one for each channel in ascending order 1 non zero on O off Notes This command is useful with combination modules when the LAS and TEC outputs need to be controlled separately For combination modules this command effects only the TEC output TEC ALL OUTput COMMC DEVICE DEPENDENT The TEC ALL OUTput command turns the TEC output on or off for each channel in ascending order Parameters Four lt
206. n 005 36 TEC Booster Mode Operation 0 cc eects 36 Chapter 3 Remote Operation Preparation for Bus Control 0 0000 cee eee eee 38 ANSI IEEE 488 2 Definitions 00000 ee 38 Syntax DiagraMS ceraian iiaei aa a a e aa e a an E iaa 38 White Space e s sciane naaa a eaa be Gee a aa aa ah aaa a ee eee eee 39 Power on Conditions sssaaa aaeeea 40 Nt Val s irasai mas aau A A ee eee Oa 40 lt PROGRAM MESSAGE TERMINATOR gt 0 00000 00s 40 lt PROGRAM MESSAGE UNIT SEPARATOR gt 5 41 lt PROGRAM HEADER SEPARATOR gt 0002000 eee eeee 42 lt compound command program header gt 00000 e eee eee 42 lt PROGRAM DATA gt Parameters 000 cee eee neces 44 lt ARBITRARY BLOCK PROGRAM DATA gt 0020000005 44 lt PROGRAM DATA SEPARATORS gt 0000000 eee ences 44 Default Parameters 0 000 eee eee 45 Getting Started with GPIB 0 0 0 2 cc ee 46 Overview of the LDC 3900 Syntax 0 0000 cece eee 46 Using Commands with Parameters 0 0 0 0 0 cece eee eee 47 Common Commands and Queries 0000 0c eee 48 PAPAL a care tae Pe aes he aig een ae at da eee ae 48 CLS adh outa hatte warts rene hee aaa eee dade sate oe 49 ESE puta piace hrs aia Ramee ae ee aaa 49 ESE Rd a a A E e 51 EOS a E E a see ea eee 51 04_10 LDC 3900 Series iii SIDN sane tehdlewsd tobe nie pate
207. n lt nrf value gt where 0 lt CR gt lt NL gt lt END gt 1 lt CR gt lt NLs gt 2 lt CR gt lt END gt 3 lt CR gt 4 lt NL gt lt ENDs gt 5 lt NL gt 6 lt AEND gt and 7 N A lt CR gt lt NL gt lt END gt number 0 is the default type This does not strictly comply with the IEEE 488 2 specification However the lt CR gt is ignored treated as white space so this terminator may be used with other IEEE 488 2 compliant instruments Use of any terminator other than number 4 removes the LDC 3900 Laser Diode Modular Controller from strict compliance with the IEEE 488 2 standard The other options are provided to allow compatibility with GPIB drivers that do not meet the IEEE 488 2 standard Although the lt CR gt is recognized as lt white space gt by the IEEE 488 2 specification it is used as a possible terminator in order to be compatible with GPIB products that do not comply with the IEEE 488 2 standard Use of terminator number 3 is especially risky with other devices that comply with the IEEE 488 2 specification This is because the lt CR gt character is treated as white space by such a device Therefore if terminator number 3 is used other IEEE 488 2 devices may indefinitely for a message termination and hang the bus TERM 5 action the lt NL gt new line terminator is selected The LDC 3900 will terminate a message with the lt NL gt character Term 4 action the lt NL
208. n register of the LASER operations of the selected LASER channel None The response is the sum of the following 1 Laser limit current 256 Output is shorted 2 Voltage limit error 512 Output is outside tolerance limit 4 N A 1024 Output on off state 8 Power limit 2048 Ready for calibration data state 16 Interlock disabled 4096 Calculation error 32 N A 8192 Error communicating with LASER board 64 N A 16384 Software error in LASER control 128 Open circuit 32768 LASER eeprom checksum error The LASER conditions which are reported to the status byte are set via the LASer ENABIe COND command for each channel The Open circuit condition is only present while a LASER output is on and when the hardware detects this condition it will turn that LASER output off Therefore the Open Circuit condition is fleeting and may be missed via the LAS COND query Therefore the user should test for the Open Circuit Event via the LAS EVEnt query The LASER 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 LAS COND response 513 means that the LASER limit current and out of tolerance LASER conditions currently exist Radix Hex Laser Cond response H108 means that the LASER Output shorted and Power limit conditions currently exist MIX Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer
209. nce disabled output E 411 TEC control error disabled output E 412 Analog section status is all 1 s or all O s power down E 413 Serial EEPROM checksum error E 415 Sensor short disabled output E 416 Incorrect Configuration for Calibration Sequence to start E 419 Setting a measurement is only valid during the calibration phase for that measurement User has tried to calibrate a measurement without first entering the required calibration mode E 433 Attempted to perform an operation which the TEC channel was not capable E 434 Change of a TEC limit value forced an update of the corresponding TEC set point E 501 LASER interlock ENABLE switch disabled output E 503 LASER open circuit disabled output E 504 LASER current limit disabled output E 507 LASER Power limit disabled output E 508 TEC output is off condition disabled LASER output E 509 TEC High Temperature Limit condition disabled LASER output E 510 LASER out of tolerance disabled output E 511 LASER control error disabled output E 512 Analog section status is all 1 s or all O s power down E 513 Serial EEPROM checksum error E 515 Laser Output must be off to change ranges E 516 Incorrect Configuration for Calibration Sequence to start E 517 Calibration for Laser Diode current must have the output on to start E 518 Calibration for the Monitor Diode must have the output on and the responsivity set to zero to start LDC 3900 Series 183 Table
210. ncremental default amount is one step The step size can be edited via the LAS STEP command its default value is 1 0 mA 1 0 mW or 1 mA if CALMD 0 depending on the mode of operation If the first optional parameter is used but not the second the LASER set point is incremented by a multiple of the LAS STEP size without changing the LAS STEP size The second optional parameter is the time in mSec between steps If both optional parameters are used the user may create an automated stepping ramp function for the LASER output If the first optional parameter is entered as zero LAS INC 0 the command will do nothing The number of steps parameter must be an integer between 0 and 65535 The minimum time to complete one increment is about 10 to 20 mSec Therefore values for the second optional parameter time between increments have a practical minimum of 20 The maximum number of mSec is 65535 Examples LAS MODE LDI LAS STEP 0 3 LAS INC action The selected channel s laser source current set point is incremented by 0 3 mA LAS MODE Ldl LAS OUT 1 LAS STEP 0 3 LAS INC 3 action The laser source current set point is incremented by 0 9 mA 0 3 mA 3 with the output on LAS MODE LDI LAS OUT on LAS STEP 0 3 LAS INC 3 5000 action The selected channel s laser source current set point is incremented by 0 3 mA three times with 5 seconds between incremental steps with the output on So the selected channel s LASER output is incre
211. ne The response is four lt nrf value gt s which correspond to the four channels in ascending order Notes A given channel s current limit is valid for all modes of Laser operation Examples LAS ALL LIM 1 response 40 0 50 0 50 0 50 0 means the laser current limit is 40 mA for channel 1 and 50 mA for channels 2 4 Laser All LIM 1 response 300 0 100 0 INF 25 0 means the laser current limit is 300 mA for channel 1 100 mA for channel 2 not valid for channel 3 channel 3 might be a TEC module or no module is present and 25 mA for channel 4 LASer ALL LIMit MDP DEVICE DEPENDENT The LASer ALL LIMit MDP command sets the laser monitor photodiode power limit values for all four channels Parameters Four lt nrf value gt s which represent the laser monitor photodiode power limit in mW for each channel in ascending order Notes When constant MDP mode is used the given channel s output current is limited only by the LIM value The LIM MDP condition may be used to shut a given channel s LASER output off But this requires the use of the LASer ENABle OUTOFF command to set bit 3 of the LASER OUTOFF ENABLE register for that channel Examples LAS ALL LIM MDP 10 10 10 10 action sets the laser output power limit to a value which corresponds to producing 10 00 mW of PD feedback optical power on all four channels Las All Limit MDp 5 1 2 4 action sets the laser output power limit to a value which corresponds to producing
212. nfirmation Press the switch and Set switch in the Laser Display switch section and check the set LDC 3900 Series OPERATION _ General Operating Procedures point operating current If it requires changing turn the knob until the desired value is displayed 6 Enable the Laser output by turning the Laser Enable key switch clockwise to the ON position Pins 1 and 2 interlock of the Laser connector must also be shorted 7 Turn the Laser output on by pressing the Output switch for the desired Laser channel The unit will automatically drive the laser to the set point current 8 If multiple Laser modules are to be controlled repeat steps c g for the other TEC channels During operation only one Laser channel may be monitored at a time on the front panel However if a Laser module has an error condition and that Laser channel is not presently selected its Channel Indicator will blink the Laser display Error Indicator will also blink Select the Laser channel with the error condition via the Adjust LAS TEC switch The error condition and all other information for that Laser channel will be displayed When the unit is powered off the state of the unit at power down is saved in non volatile memory Calibration data are stored in the individual modules Simultaneous TEC and Laser Mode Operation Follow the steps outlined below for each of the operating modes When both TEC and Laser modes are in operation the foll
213. ng over the GPIB bus Adjust Section The Adjust section is located on the right side of the LDC 3900 Modular Laser Diode Controller front panel It consists of the Adjust main control Knob and the LAS TEC adjust mode enable switches A green LAS or TEC LED indicates that a corresponding module is available for adjustment The Adjust Knob is used to change the set points enter parameter values enter the GPIB address or enter instrument calibration data The Adjust LAS TEC switches are used to enter or exit LAS or TEC adjustment mode If the Adjust LAS TEC switch is pressed so that the Adjust TEC Indicator LED is orange the unit enters TEC mode Likewise if the Adjust LAS TEC switch is pressed so that the Adjust LAS Indicator LED is orange the unit enters Laser adjust mode Only one or none channel Adjust mode TEC or LAS may be operating at any given time In order to use the Save or Recall functions both the TEC and LAS Adjust modes must be disengaged no Adjust Indicators lit in orange The GPIB address adjust mode may be entered at any time except during calibration by pressing the GPIB Local switch This adjustment mode overrides any other existing adjustment modes When the GPIB address adjustment is done the previous adjustment mode will be reinstated Automatic Set Point Adjustment If the Adjust Knob is turned during operation while a measured TEC value is being displayed and the Adjust TEC Indic
214. nnel and LAS Channel Indicators being lit green Selected LAS and TEC channels are indicated by the corresponding TEC Channel and LAS Channel Indicators being lit orange For more information see Adjust Section on page 17 Jj Las Las Las Las TEC TEC TEC TEC Figure 2 4 Adjust Section The Output section contains switches for turning the outputs on off for the LAS and TEC modules in the corresponding channels The Output Indicators are on when the corresponding channel output s are on For more information see Output Section on page 18 Note In order to turn on a Laser current output the Laser Enable switch must be on and the Laser connector s interlock pins 1 and 2 shorted see module manual for details OUTPUT 2 3 Figure 2 5 Output Section LDC 3900 Series 11 OPERATION LDC 3900 Front Panel The Parameter section is divided into TEC and Laser components When an Adjust TEC mode is selected repeatedly pressing the Parameter Select switch will cycle through the TEC parameters Likewise when an Adjust LAS mode is selected repeatedly pressing the Parameter SelectSelect switch will cycle through the Laser parameters The Parameter Set switch is used to enter the Set mode for changing parameter values For more information see TEC Parameter Section on page 21 and Laser Parameter Section on page 28 TEC QHD
215. nnels TEC ALL MODE T TEC ALL T 25 3 30 25 10 5 action sets the temperature set point to 25 3 C for channel 1 30 0 C for channel 2 25 0 C for channel 3 and 10 5 C for channel 4 The outputs are controlled to this value if the corresponding output is on TEC ALL T DEVICE DEPENDENT The TEC ALL T query returns the value of the TEC temperature measurement for all channels in ascending order Parameters None The response is four lt nrf value gt s one for each channel in ascending order Notes The measured TEC temperature is valid for all modes of TEC operation Temperature is continually updated The temperature measurement is updated approximately once every 600 msec per channel In remote operation each response value has 6 digits of precision Examples TEC ALL T response 10 4231 10 552 10 31 10 4 means the measured TEC load temperature is 10 4231 C for channel 1 10 5520 C for channel 2 10 3100 C for channel 3 and 10 4000 C for channel 4 TEC ALL V DEVICE DEPENDENT The TEC ALL V query returns the value of the TEC voltage measurement 39034 only for all channels in ascending order Parameters None The response is four lt nrf value gt s one for each channel in ascending order Notes The measured TEC voltage is valid for all modes of TEC operation Voltage is continually updated The voltage measurement is updated approximately once every 600 msec per channel Examples TE
216. nstant P mode is selected the Laser output is controlled to the constant Ipp monitor PD current or Ppp monitor PD power when the CAL PD value is non zero set point value The Iypw Indicator becomes lit when the unit is in high bandwidth constant current control mode When constant IHBW mode is selected the Laser output is controlled to the constant set point value Laser Display Switch Section The Laser Display switch section is used to select the Laser display mode Either the set point or measured laser current lpp monitor PD current or Ppp monitor PD power or measured V laser voltage values may appear on the Laser display The set point is determined by the Laser Mode selection Any of the measured Laser values may be displayed by pressing the desired Laser Display switch When a measurement display mode 1 lpp Ppp or V value is selected by pressing its switch the Laser Display Set Indicator LED will go off if it was previously on Refer to Figure 2 12 on page 15 during the discussion of the Laser Display switch section features LASER DISPLAY Ipp PPD Vv Figure 2 21 LDC 3900 Laser Display Switch Section MIL Lightwave 04 10 OPERATION LDC 3900 Front Panel Laser Display Set When the Laser Display Set switch is pressed the Laser Display Set Switch Indicator and the Laser Display Indicator of the set point mode I or Ipp Ppp will also become
217. nstant voltage source lt produces a voltage v which is directly proportional to absolute temperature over its useful range 40 C to 100 C This nominal value can be expressed as v 10mV K where v is the nominal voltage produced by the LM335 and K is in Kelvin The LDC 3900 Laser Diode Controller uses v to determine the nominal temperature Tp by the formula Tn v 10mV K 273 15 where Tn is in C The temperature Td which is displayed by the LDC 3900 Laser Diode Controller is first calibrated as follows Tq Cl C2 T where C1 and C2 are the constants stored by the user in the LDC 3900 for the LM335 When the LDC 3900 is shipped from the factory the LM335 measurement system is calibrated but the sensor C1 and C2 is not Nominally C1 0 and C2 1 In that case the temperature accuracy is typically 1 C over the rated operating range With C1 and C2 calibrated also the temperature accuracy is typically 0 3 C over the rated operating range The temperature accuracy may be improved over a narrow temperature range by a two point calibration of C1 and C2 However the LM335 is not perfectly linear and even with C1 accurately known and C2 uncalibrated there is a non linear absolute temperature error associated with the device This non linearity caused error is typically 0 3 C with the error associated with C1 assumed to be zero If a maximum absolute error of 1 C is tolerable no calibration
218. nt Parameters None Notes The actual TEC ITE display is turned off automatically when another TEC display selection is enabled In local operation the TEC ITE display is enabled by pressing the ITE switch in the TEC DISPLAY area of the front panel Examples Tec Display lte action enables the TEC display for measured current values TEC DIS ITE action enables the TEC display for measured current values 04_10 LDC 3900 Series 147 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC DISplay ITE COMM DEVICE DEPENDENT FRONT PANEL The TEC DISplay ITE query returns the status of the TEC DISPLAY ITE switch Parameters None The response is an lt nrf value gt Notes The response will be the status of the TEC DIS ITE switch 1 on 0 off In local operation the status of the TEC ITE display switch is determined by visually inspecting the LED indicator on the TEC DISPLAY ITE and SET switches The ITE measurement will be displayed if the SET indicator is off and the ITE indicator is on lit ON Examples TEC DIS ITE response 0 means that the TEC DIS ITE switch is not enabled TEC output current is not displayed Tec DISp lte response 1 means that the TEC DIS ITE switch is enabled TEC current may be displayed TEC DISplay PARAM Go DEVICE DEPENDENT FRONT PANEL The TEC DISplay PARAM command enables the TEC display to show the parameter values Parameters None Notes This command ha
219. nt set point is decremented by 0 3 mA three times with 5 seconds between decremental steps So the LASER output is decremented a total of 0 9 mA after 10 seconds LAS STEP 1 LAS Mode P Las DEC action The power set point is decremented by 1 0 mW LASer DISplay DEVICE DEPENDENT The LASer DISplay command enables or disables turns off the LASER display and LASER section s indicator LEDs Parameters An lt nrf value gt where 1 on O off Notes Turning the LASER display and LEDs off means that a message of all blank spaces is sent to the LASER display and all of the LASER section s indicator LEDs will be turned off Examples las dis 1 action turns the LASER display on and enables the LASER indicator LEDs Laser dis Off action turns the LASER display and disables the LASER indicator LEDs 04 10 LDC 3900 Series 103 COMMAND REFERENCE LDC 3900 Device Dependent Commands LAS DISplay COMMC DEVICE DEPENDENT FRONT PANEL The LASer DISplay query returns the value shown on the LASER display Parameters None The response will be character data which represents what is on the LASER display Notes Returns the actual 6 character string from the output buffer to the LASER display If the display is disabled it returns In local mode the user would read the LASER display visually Examples LAS DIS response 99 9 means the LASER display shows 99 9 Laser DISp response 0 6 means the LASER
220. odular Laser Diode Controller Not all of these messages may appear on the front panel displays Some refer to GPIB activities only for example The errors codes are numerically divided into areas of operation Errors which pertain to the following areas are listed in the ranges shown below Table 5 1 Error Code Classifications Error Code Range Area of Operation E 001 to E 099 Internal Program Errors E 100 to E 199 Parser Errors E 200 to E 299 Execution Control Errors E 300 to E 399 GPIB Errors E 400 to E 499 TEC Control Errors E 500 to E 599 Laser Control Errors MIX Lightwave LDC 3900 Series 181 182 ERROR MESSAGES A Table 5 2 LDC 3900 Modular Laser Diode Controller Error Message Codes Error Code Explanation E 001 Memory allocation failure E 101 lt program mnemonic gt is too long E 102 lt PROGRAM MESSAGE UNIT gt is too long E 103 lt DEFINITE LENGTH ARBITRARY BLOCK PROGRAM DATA gt length too long E 104 lt NON DECIMAL NUMERIC PROGRAM DATA gt type not defined E 105 lt DECIMAL PROGRAM DATA gt exponent not valid E 106 lt DECIMAL PROGRAM DATA gt digit expected E 107 lt DECIMAL PROGRAM DATA gt digit not expected E 108 lt DECIMAL PROGRAM DATA gt more than one decimal point E 109 lt DECIMAL PROGRAM DATA gt more than one exponential indic
221. of C1 or C2 is required just set C1 0 C2 1 If a maximum absolute error of 0 5 C is tolerable the one point calibration of C1 may be used If a greater accuracy is desired the two point method of determining C1 and C2 should used Note however the absolute error associated with the constant C2 may vary over different temperature ranges 04_10 LDC 3900 Series 193 194 _ One Point Calibration Method One Point Calibration Method This procedure will work for any linear temperature sensor The accuracy of this procedure depends on the accuracy of the known temperature externally measured It is used to determine the zero offset of the device and it assumes that the gain offset slope is known and is correct 1 Allow the LDC 3900 Laser Diode Controller to warm up for at least one hour Set the SENSOR SELECT switch for the desired sensor type and RECALL the constants for the particular device to be calibrated Select the C1 parameter Read and record the value of C1 Place the sensor at an accurately known and stable temperature Ta Connect the sensor to pins 7 and 8 of the LDC 3900 s 15 pin connector Set the LDC 3900 for normal constant temperature T mode operation Allow the LDC 3900 to stabilize at the known temperature Ta and read the displayed temperature Ty Determine the new value of C1 Cin from the formula Cin C1 Ta Tg and replace C1 with C1n by selecting the C1 parameter and entering the n
222. ommand Paths The LDC 3900 device dependent commands are structured into tree format see Figure 4 1 on page 84 Each of the legal paths is listed below followed by its list of path options each of which is followed by the commands themselves It is recommended that the first time user begin learning the commands by using the full path notation Once you are familiar with the commands you may wish to take advantage of the shortcuts allowed for command paths see Advanced Programming on page 61 04 10 LDC 3900 Series 83 84 com cmds CAL CLS ESE ESE ESR IDN OPC OPC PSC PSC PUD PUD RCL RST SAV SRE SRE STB TST WAI LDC 3900 Series BEEP BEEP CHECKSUM DELAY SET ERR MES LDI MES MDI RAD MDP RAD SECURE TERM TERM TIME TIMER ONLY OUT CALMD CALMD CHAN CHAN COND DEC DIS DIS EVE INC LDI LDI LDV LDV MDI MDI MDP MDP MODE SET OUT OUT ITE STB STEP STEP TOL TOL LAS ALL CAL DIS ENAB CALMD LIM MODE ONLY LDI LDI COND CALMD LDI LDI COND LDI l IHBW OUT LDV LDV EVE LDI 12 ILBW LDV LDV EVE LDV MDP MDP MDI MDI OUTOFF MDI MDP MDI MDI OUTOFF MDI MDP MDP MDP MDP SET OUT SET OUT PARAM TEC CHAN ALL CAL DIS CHAN COND CONST LIM MODE ONLY IT
223. on the Laser display The constant values will be shown on the TEC display LDC 3900 Series 13 y OPERATION LDC 3900 Front Panel The TEC Display is used to show TEC control measured and set point and parameter values It may also display errors which relate to TEC operation TEC CHANNEL nn TES UU O ERROR O TEMP LIMIT O TE CURRENT LIMIT O SENSOR OPEN C TE MODULE OPEN Figure 2 10 TEC Display The TEC Channel indicators show which TEC channel may be adjusted LED lit and whose measurements are displayed They also blink if an error occurs ona TEC channel which is not presently selected for adjustment For more information see TEC Channel Indicators on page 24 The TEC Error Indicators become lit when the corresponding TEC conditions occur For more information see TEC Error Indicators on page 24 Conditions Which Will Automatically Shut Off a TEC Output High Temperature Limit TEC Interlock Disabled see TEC module instruction manual Booster Changed While Output On see TEC module instruction manual Sensor Open While Output On see TEC module instruction manual e TEC Module Open While Output On e SENSOR Select Switch Moved While Output On e Sensor Shorted While Output On The above conditions may be defeated via GPIB using the TEC ENAB OUTOFF command Laser Functions This section gives a brief synopsis of the Laser controller sections on the LDC 390
224. orage temperatures should be in the range of 40 to 70 xC To achieve rated accuracy let the LDC 3900 Modular Laser Diode Controller warm up for about 1 hour before use TEC Mode Operation You can operate the TEC controller portion of the LDC 3900 Modular Laser Diode Controller in several modes constant T constant R or constant lyg This example is for constant T mode the most commonly used mode However the other operating modes follow similar procedures 1 Plug the LDC 3900 Modular Laser Diode Controller into an AC power source supplying the correct voltage and frequency for your unit refer to the back panel for the correct ratings 2 Turn on the LDC 3900 The TEC Output stage s will be off at power up and the unit will automatically configure its parameters to the state which existed when the power was last shut off if possible If the LDC 3900 detects that its modular configuration has changed it will configure the parameters in the default states 3 Check the setting of the SENSOR Select switches for the desired operation The sensor code for the selected TEC channel will be shown on the TEC display for three seconds during the power up sequence see Power Up Sequence on page 6 4 Press the LAS TEC switch in the Adjust section of the front panel to select the TEC 34 LDC 3900 Series im IL Lightwave 04 10 OPERATION General Operating Procedures module for adjustment Press the Select switch in the TEC Mode se
225. osition Ite Set Point 0 LIM l g set to 25 of maximum setting LIM Ty set to 99 9 xC GAIN 30 TEC STEP value 1 units depend on set point mode used with remote operation only TEC Tolerance values 0 2 xC 5 seconds C1 1 125 x 103 C2 2 347 x 10 C3 0 855 x 107 PARAMETERS not selected TEC and LASER adjust not selected LASER output off LASER DISPLAY enabled in mode Constant low bandwidth high BW for 39427 39437 mode selected LASER display showing actual current if LAS module exists LASER Set Point 0 LIM P 25 of maximum setting for laser module LASER PPD Set Point 0 LASER IPD Set Point 0 CAL PD 0 mA mW LIM 25 of maximum setting for laser module LASER STEP value 1 units depend on set point mode used with remote operation only LASER Tolerance values 10 0 mA 1 0 seconds RECALL BIN number 0 8 LDC 3900 Series MIL Lightwave OPERATION LDC 3900 Front Panel LDC 3900 Front Panel The LDC 3900 Modular Laser Diode Controller s front panel contains displays and controls for both the TEC and Laser controller hardware Each of the labeled areas on the front panel i e TEC Display or GPIB is described in a separate section later in this chapter Generally the controls are simple to operate The setup parameters however are intentionally awkward to use so that their values are not
226. output is controlled to this value if the output is on MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC T COMMON DEVICE DEPENDENT FRONT PANEL The TEC T query returns the value of the TEC temperature measurement for the selected TEC channel Parameters None The response is an lt nrf value gt Notes The measured TEC temperature is valid for all modes of TEC operation Temperature is continually updated This measurement is updated approximately once every 600 msec In remote operation the response value has 6 digits of precision In local operation the T measured value is determined by pressing the T switch in the TEC DISPLAY area of the front panel and visually reading the value on the TEC display Examples TEC T response 10 4231 means the measured TEC load temperature is 10 4231 C for the selected TEC channel Tec Mode R Tec T response 3 0778 means the measured TEC load temperature is 3 07780 C for the selected TEC channel 04_10 LDC 3900 Series 169 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC TOLerance DEVICE DEPENDENT The TEC TOLerance command allows the programmer to determine the selected TEC s set point tolerance and time window for it to occur in order that the TEC condition bit for tolerance be cleared after a TEC OUTput 1 command is issued or the set point is changed Version 3 5 and higher of the LDC 3900 allows tolerance testing for R
227. owing actual temperature if TEC module exists Temperature Set Point 0 C Resistance Reference Set Point 1 Q or 1 A or 1 mV depending on the setting of the SENSOR Select switch ITE Set Point 0 LIM ITE set to 25 of maximum LIM THI set to 99 9 C TEC STEP value 1 TEC Tolerance values 0 2 C 5 seconds GAIN 30 C1 1 125 x 10 C2 2 347 x 10 C3 0 855 x 107 CAL PD 0 0 04_10 LDC 3900 Series 45 REMOTE OPERATION _ Getting Started with GPIB Table 3 1 State of the LDC 3900 After RST LDC 3900 Condition LIM 25 of maximum LIM for the laser module LIM P 25 of maximum LIM P for the laser module Laser output off Laser Display enabled in mode Constant low bandwidth high BW with 39427 39737 mode selected Laser display showing actual current if Laser module exists Laser STEP value 1 Laser Tolerance values 10 0 mA 1 0 seconds Laser Set Point 0 Laser IPD Set Point 0 Laser PPD Set Point 0 LAS channel is the lowest existing Laser module channel 1 4 TEC channel is the lowest existing TEC module channel 1 4 Recall BIN number 0 Getting Started with GPIB This section is intended as a quick guide to the GPIB syntax and commands used by the LDC 3900 Modular Laser Diode Controller The LDC 3900 Modular Laser Diode Controller s unique device dependent
228. owing should also be considered 1 When alternating adjustments of the Laser and TEC operations the corresponding switch in the Adjust section of the front panel must be pressed 2 The Save and Recall parameter functions save the Laser and TEC parameters simultaneously 3 For channels which contain both a Laser and TEC controller in one module see the module instruction manual for details on Output control TEC Booster Mode Operation You can operate the TEC controller portion of the LDC 3900 Modular Laser Diode Controller with an external TEC current source booster Operation is the same as described in TEC Mode Operation on page 34 except that when a booster is present a control signal of 10 0 volts is used to drive the external TEC current source Also the LIM value may be increased above the normal operation maximum of 4 0 Amps to a maximum of 10 0 Amps Refer to the TEC module instruction manual for connecting and operating with an external booster 36 LDC 3900 Series MIL Lightwave CHAPTER 3 REMOTE OPERATION 5 B E a t8 a a El E E a E E E E a a The LDC 3900 Modular Laser Diode Controller can be used as a remotely controlled laser diode testing instrument Possible applications include automatic L I curve data gathering over a range of controlled temperatures In remote operating mode the LDC 3900 Modular Laser Diode Controller offers all of the features accessible from the front panel and some advanced featu
229. pplies for thermistors The appropriate algorithms are automatically implemented whenever the sensor type is selected via the back panel SENSOR Select switches However C1 and C2 must be changed by the user Gain The Gain function sets the analog feedback gain which in part determines how fast the actual temperature reaches and settles to the set point temperature If the gain is set too low 1 is lowest the TE cooler will take longer to reach the temperature set point If it is set too high 300 is highest the actual temperature may overshoot and may cycle around the set temperature The Gain Indicator becomes lit when the control loop gain level is displayed The allowed Gain values are 1 3 10 30 100 and 300 These values actually define the proportional loop gain The gain setting depends on the type of TE cooler that you are using but we can suggest guidelines for selecting the proper gain Set the gain to 1 and increase it until the actual temperature oscillates around the set temperature Then reduce the gain to the next lower value LDC 3900 Series 23 LDC 3900 Series OPERATION _ LDC 3900 Front Panel To read the gain setting press the Parameter Select switch until the Gain Indicator is lit The TEC display will show the value of the Gain setting To change the Gain sequence the parameters to the Gain value Press and hold in the Parameter Set switch turn the Adjust Knob until the desired new value
230. r LIMit MDP Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The LASer LIMit MDP query returns the value of the selected channel s laser monitor PD power limit None The response is an lt nrf value gt In local operation the limit power value is read by selecting the LIM P parameter in the PARAMETER area of the front panel and visually reading the LASER display LAS LIM MDP response 3 0 means the selected channel s monitor PD power limit is set to 3 0 mW LAS Limit MDP response 10 0 means the selected channel s monitor PD power limit is set to 10 0 mW LASer MDI Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The LASer MDI command sets the value of the optical power set point in mA if the CALMD CAL PD responsivity is 0 An lt nrf value gt which represents the selected channel s photodiode feedback current in mA If the selected channel s CALMD CAL PD parameter is not set to 0 the LAS MDI value will not be used In this case the measured MDI would be converted to MDP PPD by the CAL PD factor and the MDP PPD set point would be used In local mode the photodetector current set point would be set by first pressing the LASER MODE P switch and then pressing the SET switch and then turning the Adjust Knob until the desired value appeared on the LASER display Las Mdi 40 action The selected channel s LASER output is controlled so that the photodiode feedback cu
231. r death F 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 repair to ensure that safety features are maintained see the contact information on page xiv 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 xiii for more information Im IL Lightwave LDC 3900 xi Ld AS 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 e Ordinary Protection This product is NOT protected against the harmful ingress of moisture e Class Equipment grounded type Pollution Degree II e Installation ov
232. rance Limit condition is set in this register when the LASER output is off you will not be able to turn the LASER output on until this bit is reset The enable registers normally retain their values at power up as they were at power down unless the power on status clear flag is set true see PSC Chapter 3 The factory default value for this register is B1110100000001000 or HE808 or 59400 decimal LAS ENAB OUTOFF 2049 action enables the selected channel s LASER status outoff register so that a TEC temperature Limit on channel 1 and LASER current limit on the selected laser channel conditions will cause the LASER output to be turned off Las Enab Outoff HFFFF action enables the selected channel s LASER status outoff register so that any or all of the above conditions will cause the LASER output to be turned off Las Enable Outoff B1000 action enables the selected channel s LASER status outoff register so that a Power Limit While the Output is On will cause the LASER output to be turned off MIX Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ENAB1e OUTOFF COMMON DEVICE DEPENDENT RONT FANEL The LASer ENABle OUTOFF query returns the value of the status outoff enable register of the selected channel s LASER operations Parameters None The response is the sum of the following 1 LASER Current Limit 256 N A 2 LASER Voltage Limit 512 Output is Out of Tolerance 4 TEC Outp
233. ration the TEC CAL SENsor query may be used to determine if the LDC 3900 is ready for the user to enter a value In local operation the LDC 3900 will display Ox where x is a digit from 1 5 to indicate the calibration mode This number corresponds to the sensor switch display number 1 100 mA thermistor 2 10 mA thermistor 3 LM335 4 AD590 5 RTD Then it will enable the SET switch and beep when it is ready for the user to enter a value Tec CAL Sen action the LDC 3900 enters calibration mode for the sensor which is selected by the back panel switch Tec Cal Sensor action the LDC 3900 enters calibration mode for the sensor which is selected by the back panel switch MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC CAL SENsor COMMON DEVICE DEPENDENT FRONT PANEL The TEC CAL SENsor query is used to determine that the LDC 3900 is ready for a value to be entered during the calibration cycle of the TEC CAL SENsor mode Parameters None The response is an lt nrf value gt 1 ready 0 not ready Notes This query can be used to poll the LDC 3900 after the TEC CAL SEN command to determine if it is waiting for a value If the response is 1 the LDC 3900 is ready to receive a calibration value via the TEC R command see the Calibration section of the TEC module instruction manual A query of the TEC condition status register bit 11 has the same results In local operation the rea
234. rea for a particular switch or LED Indicator on the front panel For example TEC Display Set refers to the switch labeled Set in the TEC Display area of the front panel Note For LDC 3900 v3 2 and above If a command is sent to module which does not support the command an error E533 LAS command or E433 TEC command will be generated Also if a query is issued to a module which does not support the query in addition to the error code the response will be inf For example if the TEC V query is sent to a 39032 module the response would be inf and E433 would be generated If a command receives a parameter which is out of range the value will not be changed Instead an error will be generated either E222 for over range or E223 for under range Prior to v3 2 out of range parameters would force the setting to a minimum or maximum condition Note Some commands which expect BOOLEAN values true false will accept a non zero value as true BEEP DEVICE DEPENDENT The BEEP command controls the LDC 3900 Modular Laser Diode Controller s beeper The beeper can be used to signal error or warning conditions Parameters An lt nrf value gt 0 OFF totally disabled 1 ON enabled for normal operation and 2 beep once Notes Disabling the BEEP will prevent the audible beeper signal from working during front panel operation including the calibration signals The parameter must be a numeric value 0 1 or 2 and nota
235. red See Appendix D for information regarding error handling Parameters None The response consists of one or more error code values separated by commas Notes The response data will be a list of the current errors The errors are represented by numbers and are separated by commas A response of 0 indicates that no errors were reported The response data is sent as character data With LDC 3900 version 3 1 and higher errors are only reported over GPIB which occur during remote operation Examples ERR response 0 means no errors reported Errors response 201 407 means that the lt PROGRAM DATA gt parameter value out of range error and the High Temperature Limit error were reported since the last query LASer COMMON DEVICE DEPENDENT FRONT PANEL The LASer command path is used to get to the LDC 3900 Modular Laser Diode Controller s laser current source commands The following command paths may be reached from the LASer command path LASer ALL LASer CAL LASer DISplay LASer ENABle LASer LIMit LASer MODE LASer ONLY LASer SET The following commands may be reached directly from the LASer command path LASer CALMD LASer INC LASer OUTput LASer CALMD LASer LDI LASer OUTput LASer CHAN LASer LDI LASer MODE LASer CHAN LASer LDV LASer RANge LASer COND LASer LDV LASer RANge LASer DEC LASer MDI LASer STEP LASer DISplay LASer MDI LASer STEP LASer DISplay LASer MDP LASer TOLerance LASer EVEnt LASer M
236. red in the individual modules Laser Mode Operation You can operate the Laser current source modules of the LDC 3900 in several modes constant I constant P or constant I high bandwidth This example is for constant mode the most commonly used mode However the other operating modes follow similar procedures 1 Plug the LDC 3900 Modular Laser Diode Controller into an AC power source supplying the correct voltage and frequency for your unit refer to the back panel for the correct ratings Turn on the LDC 3900 Modular Laser Diode Controller The Laser Output stage s will be off at power up and the unit will automatically configure its parameters to the state which existed when the power was last shut off if possible If the LDC 3900 detects that its modular configuration has changed it will configure the parameters in the default states Press the LAS TEC switch in the Adjust section of the front panel to enter Laser mode for the desired Laser channel Press the Select switch in the Laser ModeLaser Mode section until the mode is selected Press the Select switch in the Parameter section and check the setting of LIM I to insure that it is compatible with the laser you are using Refer to Laser Parameter Section on page 28 if you need to change the current limit If a pre configured setup is to be recalled use the Recall feature see Save and Recall Parameter Functions on page 31 and then recheck the parameter settings for co
237. removal procedures are described in the module manuals Note Modules should be installed or removed from the LDC 3900 only when the power is off Whenever the modular configuration of the LDC 3900 is changed the unit will power up using default parameters AC Power Considerations The LDC 3900 Modular Laser Diode Controller can be configured to operate at nominal line voltages of 100 120 220 or 240 VAC Normally this is done at the factory and need not be changed before operating the instrument However check to be sure that the voltage selection displayed in the center of the power entry module on the back panel of the instrument matches the power line voltage in your area Refer to the Line Voltage selection on page 3 if it is necessary to reconfigure the input voltage range MIL Lightwave LDC 3900 Series 5 OPERATION Power Up Sequence AA warnine To avoid electrical shock hazard connect the instrument to properly earth grounded electical supply only Failure to observe this precaution can result in severe injury or death Tilt Foot Adjustment The LDC 3900 Modular Laser Diode Controller has front legs that extend to make it easier to view the LED displays To use them place the unit on a stable base and rotate the legs downward until they lock into position Rack Mounting The LDC 3900 Modular Laser Diode Controller may be rack mounted by installing a rack mount flange on either side of the enclosure All r
238. res which can only be accessed via the interface bus In remote mode you have access to commands for functions not found on the front panel such as the INC or DEC commands which automatically increment or decrement the set point by a user defined step value calculation of measured temperature to 6 digit resolution and control of the conditions which cause the TEC and Laser controller outputs to be shut off The GPIB interface allows bus control of the LDC 3900 Modular Laser Diode Controller Information can also be read by the host computer and printed or stored Other features include A concise and straight forward command set Full talk listen capability e Full serial poll capability with SRQ Full local remote capability including Local Lockout Meets ANSI IEEE 488 2 1987 standards This chapter is a guide to the syntax and usage of the various IEEE 488 2 common commands available for the LDC 3900 Modular Laser Diode Controller It also includes advanced programming tips for remote use with the device dependent commands hardware diagrams and other information relating to remote operation This chapter is divided into three parts The first part has the information for using the GPIB with the LDC 3900 Modular Laser Diode Controller It also has sections for each common GPIB ANSI IEEE 488 2 command which is supported by the LDC 3900 Modular Laser Diode Controller LX Lightwave LDC 3900 Series 37 REMOTE OPERATION
239. rns the value of the TEC s Steinhart Hart constants or the linear sensor conversion constants for all TEC channels C1 C2 and C3 are returned for each channel in ascending order Parameters None The is always in the form C1 C2 C3 C1 C2 C3 C1 C2 C3 C1 C2 C3 where the first three values are from channel 1 next three from channel 2 next three from channel 3 and last three from channel 4 Notes When the LM335 AD590 or RTD sensors are selected via the SENSOR SELECT switch only C1 and C2 are used Therefore C3 values may be ignored for these cases Appendices A B and C contain information on the use of these constants with the various sensor types Examples TEC ALL CONST response 1 111 2 03 0 85 1 111 2 03 0 85 1 111 2 03 0 85 1 111 2 03 0 85 means C1 1 111 C2 2 030 and C3 0 850 for all TEC channels TEC All Const response 1 00 2 222 0 07 1 111 2 03 0 85 1 50 2 324 0 856 1 123 2 347 0 8 means C1 1 000 C2 2 222 and C3 0 070 for channel 1 C1 1 111 C2 2 030 and C3 0 850 for channel 2 C1 1 500 C2 2 324 and C3 0 856 for channel 3 C1 1 123 C2 2 347 and C3 0 800 for channel 4 04_10 LDC 3900 Series 131 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL GAIN DEVICE DEPENDENT The TEC ALL GAIN command sets the TEC control loop gain for all four TEC channels in ascending order Parameters Four lt nrf value gt s representing the GAIN value for each channel in as
240. rrent remains constant at 40 mA Laser MDI 200 action The selected channel s LASER output is controlled so that the photodiode feedback current remains constant at 200 mA LASer MDI Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT FRONT PANEL The LASer MDI query returns the value of the selected channel s laser photodetector current measurement in mA None The response is an lt nrf value gt The response is in mA The response is valid even when the unit is not in constant P mode This measurement is updated approximately once every 600 mSec In local mode the measured photodetector current would be read by pressing the LASER DISPLAY IPD PPD switch and visually reading the LASER display assuming P mode is selected and CALPD is zero Las Mode MDP Las Calmd 0 Las MDi response 100 0 means 100 mA of photodetector current from the selected LAS channel This feedback is controlling the laser selected channel s current output LAS MODE IHBW LAS MDI response 20 0 means 20 mA of photodetector current from the selected LAS channel but photodiode monitor current is not controlling the selected channel s laser output current MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer MDP COMM DEVICE DEPENDENT FRONT PANEL The LASer MDP command sets the value of the optical power set point in mW if the CALMD CAL PD responsivity is greater than zero Parameters
241. rresponds to the smallest incremental change of the mode For example with a CSM39020 a step of 1 means 0 01 mA 0 01 mW or 1 mA if CALPD 0 Las Mode i Las i 20 Las Step 100 Las Inc Las set i action sets the selected channel s step to 1 0 mA so the Las set i query will return a value of 21 0 mA CSM39010 CSM39020 CSM39050 or CSM39420 LAS STEP 1000 action sets the selected channel s step size to 1000 could mean 10 0 mA 10 0 mW or 100 mA CSM39010 CSM39020 CSM39050 or CSM39420 LASer STEP Parameters Notes Examples LDC 3900 Series DEVICE DEPENDENT The LASer STEP query is used to read back the selected LAS channel s STEP value This value is used to increment or decrement the selected laser control mode set point by the given amount when used with the LASer INC or LASer DEC command None The is an lt nrf value gt of the selected channel s step amount The step of 1 corresponds to the smallest incremental change of the mode For example a step of 1 means 0 1 mA 0 01 mW or 1 mA if CALPD 0 A step of 9999 means 999 9 mA 99 99 mW or 9999 mA Las Mode LDI Las Step response 1 means the selected channel s step size is 0 1 mA CSM39100 or CSM39400 since Const mode is in effect LAS MODE MDP LAS CALMD 1 LAS STEP response 10 means the selected channel s step size is 0 1 mW CSM39100 or CSM39400 since Const P mode is in effect MIX Lightwave COMMAND REFERENCE LDC 3900 Devi
242. rvice Request Enable Register the Event Status Enable Register the Condition Status Enable Register and the Parallel Poll Enable Register will retain their values when power is restored to the LDC 3900 Modular Laser Diode Controller A returned value of 1 indicates that the registers listed above will be cleared when power is restored to the LDC 3900 Modular Laser Diode Controller The syntax for this query is TOOK HO PUD The Protected User Data command stores data unique to the LDC 3900 Modular Laser Diode Controller such as calibration date serial numbers etc This data is protected by restricted entry SECURE lt nrf gt command and is usually only entered at the time of service or calibration This data is a fixed size of 21 bytes The syntax of the PUD command is o les lt white lt ARBITRARY space gt 7 BLOCK I gt PROGRAM DATA gt where the user s input unique data is exactly 21 bytes 54 LDC 3900 Series MIL Lightwave REMOTE OPERATION Common Commands and Queries PUD The Protected User Device query allows the user to retrieve the contents of the PUD storage area The response is the contents of the unique data which was last entered The syntax of the PUD query is OA HOH The initial factory set response value of the PUD query is 221nnnnnnnnLLOOMMDDYYABC where the response is lt ARBITRARY BLOCK RESPONSE DATA gt nnnnnnnn represents the 8 digit s
243. s turning on the TEC output will also turn on the LAS output for that channel Examples TEC ALL OUTPUT 1 0 0 1 action turns the output on for channel 1 and 4 and turns the output off for channels 2 and 3 Tec All Out 0 0 0 0 action turns the TEC output off on all channels LDC 3900 Series 137 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ALL OUTput DEVICE DEPENDENT The TEC OUTput query returns the status of the OUTPUT switch for the selected TEC channel Parameters None The response is four lt nrf value gt s separated by commas 0 off 1 on Notes Although the status of the switch is on the corresponding TEC output may not have reached its set point value Examples Tec ALL OUT response 0 0 0 0 means that the TEC OUTPUT switch is disabled on all channels TEC All OUT response 1 0 0 0 means that the TEC OUTPUT switch is enabled for channel 1 TEC output is present for channel 1 For channels 2 4 the TEC outputs are off TEC ALL R DEVICE DEPENDENT The TEC ALL R command sets the TEC s constant thermistor resistance or linear sensor reference set point for all channels Parameters Four lt nrf value gt s which represent the thermistor or RTD resistance set point value in kW the AD590 current set point in mA or the LM335 voltage set point in mV depending on the selected sensor type The values correspond to the channels in ascending order Notes The R set point is use
244. s may be read by visually inspecting the back panel of the TEC channel in question If the response is 0 the sensor type is undetermined and a hardware error must exist Examples TEC Sensor response 1 means the selected TEC s SENSOR SELECT switch is in the THERM position and the THERM SELECT switch is in the 100 mA position Tec SEN response 3 means the selected TEC s LM335 sensor is selected by the back panel SENSOR SELECT switch The position of the THERM SELECT switch in this case is not relevant TEC SET Co DEVICE DEPENDENT FRONT PANEL The TEC SET command path is used to get to the selected TEC channel s TEC set point queries The following commands may be reached directly from the TEC SET command path TEC SET ITE TEC SET R TEC SET T TEC SET ITE DEVICE DEPENDENT FRONT PANEL The TEC SET ITE query returns the TEC constant TE current set point value for the selected TEC channel Parameters None The response represents the ITE set point for the selected TEC channel in amps Notes The selected TEC output is controlled to this set point value only when constant ITE mode is in effect In local operation the ITE set point value is read by pressing the TEC DISPLAY SET switch while in ITE mode and visually reading the TEC display Examples TEC SET ITE response 3 0 means the ITE set point is 3 000 amps for the selected TEC channel Tec Set lte response 4 0 means the ITE set point is 4 000
245. s the TEC output current so that the unit does not provide more current than your device can safely handle During operation when the TEC current limit is reached the TE CURRENT LIMIT Error Indicator will flash If the GPIB option is installed the TE current limit condition may be used to shut the TEC output off via the TEC ENABle OUTOFF command To read the current limit press the Parameter Select switch until the LIM ly Indicator is lit If the LIM Iyg value is to be changed press and hold in the Parameter Set switch turn the Adjust Knob until the desired value is displayed then release the Set switch When the Set switch is released the new value will be stored in non volatile memory The TEC current limit is displayed in Amps LIM Ty The LIM Ty function sets the maximum TEC output temperature in xC During operation when this limit is reached the TEMP LIMIT Error Indicator will flash Normally this limit will cause the TEC output to shut off unless this ability is disabled remotely via the TEC ENABle OUTOFF command To read the temperature limit press the Parameter Select switch until the LED by LIM Ty is lit The TEC display will show the value of the LIM Ty in xC To change the temperature limit sequence the parameters to the LIM Ty value Press and hold in the Parameter Set switch turn the Adjust Knob until the 22 LDC 3900 Series im IL Lightwave 04 10 OPERATION LDC 3900 Front Panel desired new
246. s the same effect as pressing the PARAMETER SELECT switch while in TEC mode The selected parameter will be displayed for three seconds The actual TEC PARAM display is turned off automatically when a TEC display selection is enabled Each time the command is issued the next TEC parameter will be selected see Section 2 10 In local operation the TEC PARAMETER is displayed by pressing the SELECT switch in the TEC PARAMETER area of the front panel while in TEC mode Examples Tec Display Param action selects a TEC parameter and displays its value TEC DIS PARAM action selects a TEC parameter and displays its value TEC DISplay R DEVICE DEPENDENT FRONT PANEL The TEC DISplay R command sets the TEC display to show the thermistor resistance AD590 current LM335 voltage or RTD resistance measurement for the selected TEC channel Parameters None Notes The actual TEC R display is turned off automatically when another TEC display selection is enabled In local operation the TEC R display is enabled by pressing the R switch in the TEC DISPLAY area of the front panel Examples TEC DIS R action enables the TEC display for measured resistance or linear sensor reference values TEC Display R action enables the TEC display for measured resistance or linear sensor reference values 148 LDC 3900 Series im IL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC DISplay R COMM DEVICE DEPENDENT FRONT
247. sconnected or connected at the selected LAS channel s output terminals LAS OUT response 1 means that the selected LAS channel s OUTPUT switch is enabled LASER output is present for the selected channel LASer RANge COMMON DEVICE DEPENDENT FRONT PANEL The LASer RANge command is not useful with the LDC 3900 LASER modules because they are single range Parameters An lt nrf value gt which is required but not used Notes This command is not useful with the LDC 3900 but was included to enhance compatibility with user s programs written for previous models of ILX Lightwave Laser Diode Controllers Examples LAS RAN 2 action does nothing LASer RANge DEVICE DEPENDENT FRONT PANEL The LASer RANge query returns a 1 Parameters None The response is an lt nrf value gt of value 1 Notes This query is not useful with the LDC 3900 but was included to enhance compatibility with user s programs written for previous models of ILX Lightwave Laser Diode Controllers Examples LAS RAN response 1 has no bearing on the current source range LAS range response 1 has no bearing on the current source range 04_10 LDC 3900 Series 123 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer SET Com DEVICE DEPENDENT FRONT PANEL The LASer SET command path is used to get to the selected LAS channel s laser set point queries The following commands may be reached directly from the LASer SET command p
248. sed for saving the instrument parameters When a save operation is performed all of the parameters which are currently in effect on the unit are stored The user selects a bin number 1 10 for saving the parameters Then when that bin number is recalled the unit is restarted and the parameters are reconfigured to the previously stored values To enter the Save Recall mode first exit both TEC and Laser modes If either TEC or Laser mode is engaged the corresponding LED indicator will be lit in orange in the Adjust section of the front panel To enable Save Recall press the switch es of the orange LAS TEC Indicators so that all indicators are either green or off Then press the Select switch in the Parameters section of the front panel When the Select switch is pressed in Save Recall mode the unit enters the Select mode Then the Save Indicator LED becomes lit and the unit displays the Save bin number If the Select switch is pressed again the Recall Indicator LED becomes lit and the unit displays the Recall bin number If the Select switch is released the Select mode state continues for three seconds after which the instrument reverts to its former state The Save indicator becomes lit when the unit is displaying a save bin number The pin number is shown on the TEC display as a number in the range 1 10 Bin 0 holds the reset default parameters The Recall Indicator becomes lit when the unit is displaying a recall b
249. ser channel LED will be orange and the appropriate parameter or measurement for that channel will be displayed on the Laser display If a Laser channel which is not selected for adjustment has an error condition the Laser channel LED of the channel with the error will blink and the Error light will also blink Laser Error Indicators The functions of the LDC 3900 Modular Laser Diode Controller s Laser error indicators are shown in Table 2 2 on page 24 Refer to Figure 2 23 on page 30 during the discussion of the Laser error indicators Error codes are explained in Chapter 5 Error Messages The Error Indicator and Channel Indicator s blink whenever an error occurs on a Laser channel which is not presently selected LASER CHANNEL mW uw NNE DO H L mA pA 123 4 DD J Vv C ERROR CI OPEN CIRCUIT C CURRENT LIMIT c INTLK ENBL KT OUTPUT SHORTED C POWER LIMIT Figure 2 23 LDC 3900 Laser Error Section LDC 3900 Series MIL Lightwave OPERATION Save and Recall Parameter Functions Table 2 3 Laser Error Indicators Error Condition Action Interlock or LASER ENABLE pins 1 and Output off INTLK ENBL light flashes at 1 Hz 2 of the LASER connector must be shorted Open circuit Output off OPEN CIRCUIT light flashes at 1 Hz Output shorted OUTPUT SHORTED light comes on This indicator becomes lit whenever the LASER output is off Current limit CURRENT LIMIT light flashes
250. sing an IOTech 50 GP488 controller card and PERSONAL488 software I0Tech P O Box 21204 Cleveland 60 OH 44121 This program assumes that the GPIB address of the LDC 3900 is 01 70 176 LDC 3900 Series im IL Lightwave 04_10 COMMAND REFERENCE LDC 3900 Programming Examples 80 This program was written in GWBASIC Microsoft Corp 90 100 INITIALIZE PROGRAM PARAMETERS 110 a 120 ADS 01 Set GPIB address for LDC 3900 130 OUTS OUTPUT Used in output subroutine 140 200 INITIALIZE THE GPIB DEVICE DRIVERS 210 220 OPEN DEV IEEEOUT FOR OUTPUT AS 1 230 OPEN DEV IEEEIN FOR INPUT AS 2 240 IOCTL 1 BREAK Clear driver 250 PRINT 1 RESET 260 CMDS RST GOSUB 1000 Reset the LDC 3900 to default values 270 300 1 NITIALIZE THE OUTPUT PRINT HEADER 310 320 CLS Clear the screen 330 340 PRINT LASER OUTPUT vs DRIVE CURRENT at 10 DEGREE C STEPS 350 PRINT 360 PRINT Temperature Drive Current Output 370 PRINT C mA mW 380 PRINT LDC 3900 Series 177 COMMAND REFERENCE LDC 3900 Programming Examples Example Program 4 3 400 INITIALIZE LDC 3900 Modular Laser Diode Controller 410 CMDS Tec Chan 1 Las Chan 2 GOSUB 1000 Set the TEC and LASER channels
251. stant temperature T resistance linear sensor reference R or TE current 12 LDC 3900 Series MIL Lightwave 04 10 OPERATION LDC 3900 Front Panel lrg control modes The LED Indicators show the selected mode For more information see TEC Mode Section on page 18 TEC MODE SELECT Figure 2 7 TEC Mode The TEC Display switch section is used to select the measured T R or lyg values or the set point value The set point is determined by the TEC Mode selection For more information see TEC Display Switch Section on page 19 Figure 2 8 TEC Display When the Adjust TEC mode is selected the TEC set point may be displayed and adjusted automatically by simply turning the Adjust Knob For more information see TEC Mode Select on page 19 The TEC Parameters are TE current limit LIM lyg high temperature limit LIM Thy constants CONST for converting from sensor measurements to temperature and control loop gain Gain For more information see TEC Parameter Section on page 21 TEC GIO PARAMETER GMINDLASER O LMI ve LMI O LMT H LIMP SELECT UU CONST CALPD O O GAIN O SAVE SET RECALL o Figure 2 9 TEC Parameters When the CONST parameter is selected the constants C1 C2 and C3 are sequenced by pressing the Parameter Select switch and a corresponding message of 1 2 or 3 will be shown
252. t until the Event Register is queried or the LDC 3900 is powered off Conditions reflect the current state of the device and therefore may change many times during operation Querying a Condition Register does not change its contents The LDC 3900 Modular Laser Diode Controller contains Event and Condition Registers for TEC and Laser controller operations It also contains the Standard Event Status Register which reports events for general operation of the LDC 3900 64 LDC 3900 Series MIL Lightwave REMOTE OPERATION Status Reporting Modular Laser Diode Controller The Standard Event Status Register conforms to the IEEE 488 2 standard LASER Current LASER Condition Statu Volta LASer CONI N A 4 Channels Power e GEEREEE ie 9 N A N A 7 Oper Output Out o Output Ready for Calibration Calculator LASER Boar LASER Contr 5 LASER EEPH Standar Event Status i Operatior TP EE BPEL zi est LASER Event Statu iran E Query 4 Channel S Device Dependent 4 Execution Command k 6 User 7 Power andar at Sat ens 150 QUEUE 9 Tolerance Statu ESE 0T 10 Outou Stat EE NOT EMPTY a a tu ledt 2 Calculatior ue LASER Board Communication 14 LASER Control
253. tant current mode for all channels Parameters None Notes This command sets the Ilbw mode for all four channels at once Examples LAS all mode ILBW action enables the laser low bandwidth constant current mode on all channels LASer ALL MODE MDP DEVICE DEPENDENT The LASer ALL MODE MDP command selects laser constant power mode for all channels Parameters None Notes This command sets the MDP mode for all four channels at once Examples las all mode mdp action enables the laser constant power mode on all channels LASer ALL ONLY DEVICE DEPENDENT The LASer ALL ONLY command path is used to get to the global laser only commands The following commands may be reached directly from the LASer ALL ONLY command path LASer ALL ONLY OUTput 04_10 LDC 3900 Series 95 96 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL ONLY OUTput Parameters Notes Examples DEVICE DEPENDENT The LASer ALL ONLY OUTput command turns the laser output only on or off for each channel These commands effect all channels regardless of the LAS channel selection Four lt nrf value gt s one for each channel in ascending order 1 non zero on O off This command is useful with combination modules when the LAS and TEC outputs need to be controlled separately For combination modules this command effects only the LAS output After a channel s output is turned on it may be useful to wait unti
254. ted and the R set point parameter will not be changed If an entered value is less than 0 001 an error E223 will be generated and the R set point parameter will not be changed In local operation the R set point is entered by selecting ADJUST TEC and R modes pressing the TEC DISPLAY SET switch adjusting the Adjust Knob within 3 seconds and then releasing the SET switch when the desired value is shown on the TEC display TEC R 20 5 action sets the set point thermistor or RTD resistance to 20 5 kQ or sets the AD590 current to 20 5 mA or sets the LM335 voltage to 20 5 mV for the selected TEC channel TEC Mode R TEC R 10 action sets the set point thermistor or RTD resistance to 10 0 KQ or the AD590 current to 10 0 mA or the LM335 voltage to 10 0 mV for the selected TEC channel The TEC output sensor is controlled to that value if the output is on TEC R Parameters Notes Examples 04 10 DEVICE DEPENDENT FRONT PANEL The TEC R query returns the value of the TEC thermistor or RTD resistance or AD590 current or LM335 voltage measurement for the selected TEC channel None The response value is the measured TEC thermistor or RTD resistance in kQ or AD590 current in mA or the measured LM335 voltage in mV TEC load temperature is derived from the thermistor resistance or linear sensor reference measurement for the selected TEC channel This measurement is updated approximately once every 600 msec In
255. ted LAS channel Parameters None Notes After this command is issued the LDC 3900 Modular Laser Diode Controller will automatically enter the LASER photodiode current calibration mode for the selected LAS channel When the LDC 3900 Modular Laser Diode Controller is ready the user should enter the true measured value This procedure is outlined in the Calibration section of the LASER module instruction manual If the LASER output is not ON or the CALMD CAL PD parameter value is O or the P mode is not selected the LDC 3900 Modular Laser Diode Controller will beep each time you try to enter this mode indicating a calibration procedural error In remote operation the LASer CAL MDI query may be used to determine if the LDC 3900 Modular Laser Diode Controller is ready for the user to enter a value via the LASer MDI command In local operation the LDC 3900 Modular Laser Diode Controller will BEEP when it is ready for the user to enter a value Examples Las CAL MDI action the LDC 3900 Modular Laser Diode Controller enters the LASER photodiode current calibration mode LAS Chan 1 Cal MDI action the LDC 3900 Modular Laser Diode Controller enters the LASER photodiode current calibration mode for channel 1 LASer CAL MDI COMN DEVICE DEPENDENT FRONT PANEL The LASer CAL MDI query is used to determine that the LDC 3900 Modular Laser Diode Controller is ready for a value to be entered during the calibration cycle of the LASer CAL MDI mode
256. ter Select switch is used to enter Select mode While the Adjust TEC Indicator lit is orange press the Parameter Select switch to enter this mode When the Select mode is first entered the LIM lyg Indicator becomes lit and the unit displays the current limit value in Amps All indicators in the TEC Display switch section are turned off If the Parameter Select switch is released this 04_10 LDC 3900 Series 21 OPERATION LDC 3900 Front Panel state continues for three seconds after which the instrument reverts to its former state If the Parameter Select switch is pressed repeatedly successive parameter values are displayed with the appropriate Parameter Setup Indicator LED being lit The order of cycling through the parameter list is LIM lyg LIM Ty Const C1 C2 and C3 in succession Gain then back to LIM lyg and so on While the Const parameters are selected the corresponding Const number 1 2 or 3 is shown in the Laser display TEC Parameter Set The Parameter Set switch is used to enter Set mode where parameter values are stored into non volatile memory If the Parameter Set switch is pressed while the unit is in Select mode the unit will enter Set mode While the Parameter Set switch is held in the selected parameter value can be change by rotating the Adjust Knob The new value is stored in non volatile memory when the Parameter Set switch is released LIM lg The LIM lyg function limit
257. the TEC channels TEC ALL R 4 Sets all the channels constant R resistance reference set points TEC ALL R NONE Returns all the TEC channels measured R resistance reference values measured about every 600 msec TEC ALL SEN NONE Returns SENSOR SELECT position for all the TEC channels TEC ALL T 4 Used to set all the channels TEC constant T temperature set points TEC ALL T NONE Returns all the channels TEC measured temperature values measured about every 600 msec TEC ALL V NONE Returns all the channels TEC voltage values measured about every 600 msec TEC CAL ITE NONE Used to enter the present TEC channel s bipolar current source calibration mode TEC CAL ITE NONE Returns the ready state for entering the present channel s TEC current source calibration value TEC CAL SEN NONE Used to set the present channel s sensor calibration constant sensor type depends on rear panel sensor switch setting TEC CAL SEN NONE Returns the ready state for entering the present channel s sensor calibration value TEC CAL V NONE Used to enter the present channel s TEC voltage calibration mode 39034 only TEC CAL V NONE Returns the ready state for entering the present channel s TEC voltage calibration value 39034 only TEC CHAN 1 Used to select the TEC adjustment channel TEC CHAN NONE Returns the number of the TEC adjustment channel TEC COND NONE Returns the value of the channel s TEC condition register TEC CONST 3
258. tionally the LDC 3900 Modular Laser Diode Controller s OCIS and OQIS idle states are set with the RST command With LDC 3900 version 3 1 and higher the CLS function is also performed automatically when the RST is performed The Operation Complete Command Idle State OCIS is the state which the LDC 3900 is in when it is no longer waiting for any operation to complete after an OPC command has been executed The Operation Complete Query Idle State OQIS is the state which the LDC 3900 is in when it is no longer waiting for any operation to complete after an OPC query has been executed These idle states allow the LDC 3900 to complete its reset process and have no operations pending before continuing with any other commands after the RST is executed 56 LDC 3900 Series MIL Lightwave REMOTE OPERATION Common Commands and Queries The syntax for the RST command is The Save command stores the current state of the LDC 3900 in non volatile local memory A particular state is then recalled by using the RCL recall command see RCL on page 55 There are 10 unique states which can be stored The syntax of the SAV command is KOKORO E lt white lt DECIMAL space gt 7 NUMERIC S PROGRAM DATA gt SAV where the data value must round off to an integer between 1 and 10 The rounded integer value corresponds to a unique saved state which can be recalled by using the same value with the
259. truction manual After this command is issued the selected TEC channel will automatically change to ITE mode turn the TEC output on determine its zero current offset set the ITE limit to 4 0 amps and drive the output to 1 0 amps This procedure is outlined in the Calibration section of the TEC module instruction manual In remote operation the TEC CAL ITE query or bit 11 of the TEC status condition register may be used to determine if the LDC 3900 is ready for the user to enter a value In local operation the TEC ITE calibration mode is entered by pressing the LOCAL GPIB and TEC DISPLAY ITE switches at the same time The LDC 3900 will BEEP when it is ready for the user to enter a value the SET switch is enabled Examples Tec CAL ITE action the selected TEC channel enters calibration mode for current on the selected TEC channel Tec Cal lte action the selected TEC channel enters calibration mode for current on the selected TEC channel 04_10 LDC 3900 Series 141 142 COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC CAL ITE Parameters Notes Examples DEVICE DEPENDENT FRONT PANEL The TEC CAL ITE query is used to determine that the selected TEC channel is ready for a value to be entered during the calibration cycle of the TEC CAL ITE mode None The response is an lt nrf value gt 1 ready 0 not ready This query can be used to poll the selected TEC channel after the TEC CAL ITE
260. ure 3 11 on page 65 The syntax of the SRE query is OO STB The Read Status Back query allows the programmer to read the status byte and Master Summary Status bit The response to this query is an integer value of the contents of the Status Byte Register where bit 6 represents the MSS Master Summary Status bit and not the RQS message see Figure 3 11 on page 65 The syntax of the STB query is Oro o gt 04 10 LDC 3900 Series 59 nan REMOTE OPERATION W Common Commands and Queries TST The Self Test query causes an internal self test and returns a response when the self test is complete The syntax of the TST query is O The response is lt DECIMAL NUMERIC RESPONSE DATA gt where the value of the response is 0 if the self test completes with no errors If the response is a value other than 0 the self test was not completed or it was completed with errors detected WAI The Wait to Continue command prevents the LDC 3900 from executing any further commands until the No Operation Pending flag is true This allows the programmer to make the LDC 3900 wait for the completion of an operation before continuing For more information on the operation complete OPC flag see Operation Complete Definition on page 66 The syntax for the WAI command is QO 60 LDC 3900 Series MIL Lightwave REMOTE OPERATION Advanced Programming Advanced Programming Once you have become famili
261. urned off if this limit is reached unless this condition to turn the Laser output off is disabled via the remote LASer ENABle OUTOFF command The maximum LIM P value depends on the laser module type Refer to the Laser module instruction manual During operation when the Laser power limit is reached the POWER LIMIT Error Indicator flashes CAL PD The CAL PD Indicator becomes lit when the monitor photodiode responsivity parameter is displayed The responsivity is displayed in uA mW The responsivity is entered by the user in uA mW after performing the following measurements Measure with a calibrated detector the output power of the device Measure the corresponding photodiode current LDC 3900 Series 29 30 A OPERATION E LDC 3900 Front Panel e Calculate the responsivity by dividing the optical power into the corresponding photodiode current This value is normally used to convert between optical power and optical current of the monitor photodiode This parameter is used to convert between lpp and Ppp values However when the CAL PD value is set to zero the unit may be operated in constant Ipp mode When the CAL PD value is zero and P mode is selected the Laser output will be controlled to the lpp set point value and the Ppp display will indicate when it is selected Laser Channel Indicators When a Laser channel is selected for adjustment see Adjust Section on page 17 the corresponding La
262. urrent high bandwidth or P optical power LAS MODE IHBW NONE Sets the present LAS channel to constant current high bandwidth mode LAS MODE ILBW NONE Sets the present LAS channel to constant current low bandwidth mode LAS MODE MDP NONE Sets the present LAS channel to constant optical power mode LAS ONLY OUT 1 Set the present channel s LAS output only on or off Useful with combination modules LAS OUT 1 Same action as setting the present LAS channel s OUTPUT switch on off LAS OUT NONE Returns the present LAS channel s OUTPUT switch status LAS SET LDI NONE Returns the present channel s constant current set point LAS SET MDI NONE Returns the present channel s constant optical power set point if the PD responsivity is 0 LAS SET MDP NONE Returns the present channel s constant P optical power set point if the PD responsivity is non zero LAS STB NONE Returns the present channel s status summaries for conditions and events LAS STEP 1 Used to set the present channel s LAS step value for use with DEC or INC commands Defaults to a step of 1 1 step is equal to the display resolution for the parameter For example 1 0 1 uA for Ipd on 39050 module Range is 1 9999 steps LDC 3900 Series MIL Lightwave 04 10 COMMAND REFERENCE LDC 3900 Device Dependent Commands Table 4 2 LDC 3900 Device Dependent Command Summary
263. used to convert between IPD and PPD values The units of this parameter are microamps milliwatt LAS ALL CALMD 0 0 0 0 action sets the CAL PD parameter to 0 for channels 1 4 This enables the constant IPD mode of operation for all channels Laser Calmd 1 0 0 0 action sets the CAL PD parameter for channel 1 to 1 00 microamp milliwatt Therefore a photodiode feedback current of 1 microamp will cause the PPD display to read 1 milliwatt for channel 1 For channels 2 4 the CAL PD parameter is set to 0 This enables the constant IPD mode of operation for channels 2 4 MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL CALMD DEVICE DEPENDENT The LASer ALL CALMD query returns the value of the laser s photodiode feedback responsivity CAL PD parameter setting for each LAS channel in ascending order Parameters None The response is four lt nrf value gt s separated by commas The response values correspond to the channel order 1 2 3 4 Notes If a value is 0 the corresponding LAS channel will be set to operate in constant IPD mode and the IPD set point value will be in effect If this value is non zero the corresponding LAS channel will be set to operate in constant PPD mode and the PPD set point value will be in effect Examples LASER ALL CALMD response 0 0 0 5 3 3 0 256 means that LAS channel 1 is set for operation in constant IPD mode if P mode is also selected LAS channels
264. ut is Off Channel 1 Event 1024 TEC Output is Off Channel 4 Event 8 Power Limit With Output On 2048 TEC High Temp Limit Channel 1 Condition 16 N A 4096 Hardware Error 32 TEC Output is Off Channel 2 Event 8192 TEC High Temp Limit Channel 1 Condition 64 TEC Output is Off Channel 3 Event 16384 TEC High Temp Limit Channel 1 Condition 128 N A 32768 TEC High Temp Limit Channel 1 Condition 1 If this bit is enabled with the output off the output may never turn on Notes The selected channel s enabled LASER events can be set by using the LASer ENABle OUTOFF command The selected channel s LASER output status can be monitored by the LASer EVEnt query Examples LAS ENAB OUTOFF response 1025 means that the selected channel s Current Limit condition and a TEC Output off condition on channel 4 will cause the selected channel s LASER output to be turned off Note if there is no TEC present in channel 4 the selected LASER s output will be disabled too Radix Hex Las Enab Outoff response HFFFF means that all of the above conditions will cause the selected channel s LASER output to be turned off 04_10 LDC 3900 Series 113 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer EVEnt Ci DEVICE DEPENDENT RON The LASer EVEnt query returns the value of the selected channel s status event register of the LASER operations Parameters None The is the sum of the follow
265. utput of the TEC controller One of the following may be selected at one time 18 LDC 3900 Series Mm LX Lightwave OPERATION LDC 3900 Front Panel constant temperature T constant thermistor resistance linear sensor reference R or constant TEC current lyg mode SELECT Figure 2 16 LDC 3900 TEC Mode Section The corresponding Adjust TEC indicator must be orange before adjusting the parameters of the TEC Mode functions Refer to Figure 2 7 on page 13 for the discussion of the features in the TEC Mode section of the LDC 3900 Modular Laser Diode Controller front panel TEC Mode Select The Select switch is used for selecting one of the three TEC modes available The selected mode will be indicated by the corresponding lit LED Indicator If the Select switch is pressed repeatedly the TEC modes are cycled through in the order T R It then back to T and so on with the appropriate TEC Mode Indicator being lit TEC Mode Indicators The T indicator becomes lit when the unit is in the temperature control mode When the unit is in constant temperature mode the TEC is controlled to the constant T set point value The R indicator becomes lit when the unit is in the sensor resistance reference control mode When the unit is in constant R mode the TEC is controlled to the constant R set point value in kW for back panel SENSOR Select settings of 100 or 10 mA thermistor sensor currents in mV for the LM335
266. vailable 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 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 3900 xiii Ld ee 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 In the United States Online 2 0 0 0 eee Or mail to ILX Lightwave Corporation P O Box 6310 Bozeman Montana U S A 59771 www ilxlightwave com In Europe Optical Test and Calibration Ltd Listerhills Science Park Bradford BD7 1HR United Kingdom Phone 44 1274 393857 Fax 44 1274 393336 Online www otc co uk Email sales otc co uk In China ETSC Technologies Co 9 F Building 1 SBI Street Dongxin Road East Lake High Tech Development Zone Wuhan Hubei 430074 PRC
267. value is on the TEC display then release the Parameter Set switch When the Parameter Set switch is released the new value will be stored in non volatile memory CONST These are the constants of the Steinhart Hart equation that the user enters to calibrate the TEC for different thermistors or linear sensors temperature conversions The Steinhart Hart equation is used to derive temperature from the non linear resistance of an NTC Negative Temperature Coefficient thermistor When a linear sensor device such as an AD590 LM335 or RTD is used only C1 and C2 need to be entered and a linear equation is used The range of values for C1 C2 and C3 are 50 000 to 50 000 To read a C1 C2 or C3 constant press the Parameter Select button until it sequences to CONST The CONST Indicator will become lit and a message 1 2 or 3 will be displayed on the Laser display to indicate which constant is selected To change the value press and hold in the Parameter Set switch and turn the Adjust Knob until the correct value is displayed Release the Parameter Set switch to store the new value in non volatile memory Appendix B contains information on sensor calibration constants for AD590 LM335 and RTD sensors Since these devices are used over their linear range the constants C1 and C2 are used in this case to determine a linear approximation of the temperature rather than the Steinhart Hart non linear approximation which a
268. width modes on a given channel This measurement is updated approximately once every 600 mSec per channel Examples LAS ALL Idi response 30 0 29 9 25 13 0 0 means the measured laser output current is 30 0 mA for channel 1 29 9 mA for channel 2 25 13 mA for channel 3 and 0 0 mA for channel 4 Laser ALL LDI response 100 1 0 0 INF INF means the measured laser output current is 100 0 mA for channel 1 0 0 mA for channel 2 and not a valid measurement on channels 3 and 4 could be because no LAS or combination module is present in channels 3 and 4 04_10 LDC 3900 Series 89 COMMAND REFERENCE LDC 3900 Device Dependent Commands LASer ALL LDV DEVICE DEPENDENT The LASer ALL LDV query returns the measured laser voltages for all four channels in ascending order Parameters None The response is four lt nrf value gt s separated by commas Notes Response is the measured laser output voltages from all four channels for either low or high bandwidth modes Each measurement is updated approximately once every 600 mSec per channel Examples LAS all ldv response 3 03 1 23 0 01 0 0 means the measured laser output voltage is 3 030 volts on channel 1 1 230 volts on channel 2 0 010 volts on channel 3 and 0 000 volts on channel 4 Laser ALL LDV response 1 0 INF INF INF means the measured laser output voltage is 1 000 volts on channel 1 Channels 2 4 have no valid measurements for laser voltage could
269. will be the status of the TEC DIS T switch 1 on O off In local operation the status of the TEC T display switch is determined by visually inspecting the LED indicator on the TEC DISPLAY T and SET switches The T measurement will be displayed if the SET indicator is off and the T indicator is on lit ON Examples TEC Dis T response 0 means that the TEC DIS T switch is not enabled TEC load temperature is not displayed Tec dis T response 1 means that the TEC DIS T switch is enabled temperature may be displayed for the selected TEC channel TEC ENABle LDC 3900 Series DEVICE DEPENDENT The TEC ENABle command path is used to get to the selected TEC channel s TEC status enable commands and queries The following commands may be reached directly from the TEC ENABle command path TEC ENABle COND TEC ENABle COND TEC ENABle EVEnt TEC ENABle EVEnt TEC ENABle OUTOFF TEC ENABle OUTOFF MIL Lightwave COMMAND REFERENCE LDC 3900 Device Dependent Commands TEC ENABle COND COMMON DEVICE DEPENDENT RON VEL The TEC ENABle COND command sets the status condition enable register of the TEC operations for the selected TEC channel These conditions are summarized in bit 1 of the status byte Parameters An lt nrf value gt whose sum represents the enabled bits 1 TE Current Limit 256 N A 2 Voltage Limit Error 512 Output Out of Tolerance 4 N A 1024 Output On 8 High Temperature Limit 2048

LDC-3900 Front Panel - Newport Corporation

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