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C A L I B R A T I O N   A N D   T R O U B L E S H O O T I N G

Calibration Overview

04_09

LDC-3700C Series

 149

 

C H A P T E R  

5

I

TE

 Current Calibration

The following procedure is for calibrating the I

TE

 bi-polar constant current source.  

This procedure calibrates the zero current set point, then it automatically drives 
the TE current output to internally set limits of ±2.000 amps.  When each of these 
values is reached and is stable, the user enters the actual value of the current, as 
measured by an external DMM.  The LDC-3700C Series Laser Diode Controller 
then automatically calibrates the TEC current source and limits. 

1

With the output off, connect a 1 

, 20 W resistor across the TEC output terminals (TE 

 and TE Module -).

2

Connect a calibrated DMM across the load resistor.  You will be calculating TE current in 
the following manner using Ohm's Law:

I = V / R

where V is the accurately measured voltage across the resistor, and R is the accurately 
measured load resistance.  I is the calculated current in Amps.  (A 4-point probe 
resistance measurement is recommended.)

3

The TEC output must be off in order to enter the I

TE

 calibration mode.  Enter the 

TEC:OUTPUT OFF

 command.

4

Enter the 

TEC:CAL:ITE

 command to place the controller in TEC Current Calibration 

mode. 

The TEC display indicates a small current in Amps as the temperature controller 
calibrates itself for a zero current level.  After 20 seconds, the TEC controller drives the 
output to 2.000 amps. Once stable, the temperature controller is ready to enter the actual 
TE current value.

5

Enter the TE current value using the

 TEC:ITE <nrf value> 

command. The (absolute 

value of the) actual ITE value is the

 <nrf value>

.

The controller drives the TE output current to the negative value of -2.000 Amps.

6

Repeat step 5 for the negative polarity of the TEC output current.

After the negative polarity value of the TEC output is entered, the controller automatically 
calibrates its current limits and set points, indicated by the flashing TE Current Limit 
indicator. The controller then returns to the state before calibration. 

Содержание LDC-3700C Series

Страница 1: ...oller LDC 3700C Series 70041001 April 2009 ILX Lightwave Corporation 31950 Frontage Road Bozeman MT U S A 59715 U S Canada 1 800 459 9459 International Inquiries 406 556 2481 Fax 406 586 9405 ilx cust...

Страница 2: ......

Страница 3: ...Chapter 1 Introduction and Specifications Product Overview 1 Initial Inspection 1 Installing the LDC 3700C 2 Grounding Requirements 2 AC Line Power Requirements 2 USB 2 GPIB Connector 3 The GPIB Addr...

Страница 4: ...21 Adjusting the Set Point 21 Set Current Source Limit 22 Set Compliance Voltage Limit 23 Automatic Shutoff Conditions for Laser Output 24 Operating a Laser in Constant Power Mode P 24 Entering Photod...

Страница 5: ...ace Messages 44 Talkers Listeners and Controllers 44 GPIB Cable Connections 45 The GPIB Connector 45 Reading the GPIB Address 46 Changing the GPIB Address 46 Changing Operation from Local to Remote 47...

Страница 6: ...35 Sensor Calibration 140 ITE Current Calibration 141 Local Calibration of the Laser Current Source 142 Current Source Calibration 142 IPD Current Calibration 144 Laser Forward Voltage Measurement Cal...

Страница 7: ...ector 17 Figure 2 3 Rear Panel TEC Connector 19 Figure 2 4 LDC 3700C Series Rear Panel 39 Figure 2 5 Rear Panel TEC Connector 41 Figure 3 1 GPIB Cable Connections 45 Figure 3 2 GPIB Connector Diagram...

Страница 8: ...L I S T O F FIG U R E S vi LDC 3700C Series...

Страница 9: ...3 1 Substitute Parameter Names 50 Table 3 2 Invalid Syntax Command Strings 52 Table 3 3 LDC 3700C Commonly Used Commands 54 Table 3 4 Default Settings for Output Off Registers 58 Table 4 1 Remote Comm...

Страница 10: ...L I S T O F TA B L E S viii LDC 3700C Series...

Страница 11: ...which can result in minor or moderate injury or damage to the product or equipment WARNING Warning indicates a potentially dangerous situation which can result in serious injury or death WARNING Visi...

Страница 12: ...oor use only Ordinary Protection This product is NOT protected against the harmful ingress of moisture Class I Equipment grounded type Mains supply voltage fluctuations are not to exceed 10 of the nom...

Страница 13: ...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 shippe...

Страница 14: ...and on the shipping paperwork ILX Lightwave recommends you insure the shipment If the original shipping container is not available place your instrument in a container with at least 3 inches 7 5 cm o...

Страница 15: ...U S A 59771 www ilxlightwave com When you contact us please have the following information If ILX Lightwave determines that a return to the factory is necessary you are issued a Return Authorization...

Страница 16: ...WA R R A N T Y xiv LDC 3700C Series in a container with at least 3 inches 7 5cm of compressible packaging material on all sides We look forward to serving you even better in the future...

Страница 17: ...ature controller The current source provides a high stability output with a fully redundant current limit and multiple laser protection features The built in temperature controller can work with most...

Страница 18: ...um power consumption is 360 VA Volt Amps The instrument s operational voltage is configured at the factory and cannot be changed However check to make sure the voltage printed on the back panel of the...

Страница 19: ...address set to 1 You can change the LDC 3700C s GPIB address locally via front panel A procedure for changing the address can be found in the section Changing the GPIB Address on page 46 Tilt Foot Ad...

Страница 20: ...ic shock do not perform any maintenance on the instrument Qualified service personnel are required to wear protective eyeglasses and anti static wrist bands while working on the LDC 3700C Series Laser...

Страница 21: ...tain Repair Services You may have to return your controller to the ILX Lightwave facility at some time for repair or service whether it is under warranty or not There is a charge for repairs after the...

Страница 22: ...Term Stability 24 hours 3 40 ppm 40 ppm 40 ppm Noise and Ripple A rms 4 High Bandwidth Mode 1 5 A 4 A 15 A lo range 20 A hi range Low Bandwidth Mode 1 5 A 2 A 10 A Transients Operational5 2 mA 3 mA 4...

Страница 23: ...while driving calibration load Accuracy is dependent upon load and cable used LDC 3714C LDC 3724C LDC 3744C Accuracy setpoint of FS 0 05 0 05 0 05 EXTERNAL ANALOG MODULATION Input 0 10 V 1 k 0 10 V 1...

Страница 24: ...e Voltage 8 V DC Short Circuit Output Current 4 Amps Maximum Output Power 32 Watts Current Noise and Ripple7 1 mA rms Current Limit Range 0 to 4 Amps Current Limit Set Accuracy 0 05 Amps Control Algor...

Страница 25: ...tput over a bandwidth of 10 Hz 10 MHz 8 When ordered with TSC 599 RTD Sensor Converter 9 Nominal temperature coefficients It and Vt apply over the rated IC temperature sensor range 10 Software limits...

Страница 26: ...Weight LDC 3714C 22 5 lbs 10 2 kg LDC 3724C 22 5 lbs 10 2 kg LDC 3744C 25 lbs 11 3 kg Power Requirements 100 115 VAC 220 240 VAC 48 66 Hz Temperature 0 C to 40 C operating 40 C to 70 C storage Humidit...

Страница 27: ...installation into a standard 19 inch wide rack RM 136 Temperature Controlled Laser Diode Mount LDM 4407 Temperature Controlled Laser Diode Mount available with collimating assembly LDM 4412 DIL Laser...

Страница 28: ...I N T R O D U C T I O N A N D S P E C I F I C A T I O N S General LDC 3700C Specifications 12 LDC 3700C Series C H A P T E R 1...

Страница 29: ...e power cord and check the line power fuse Note The instrument contains a laser current source that has remote interlock capability This allows you to connect the interlock circuit to an external swit...

Страница 30: ...lected RECALL BIN number 0 TEC DISPLAY enabled in T mode TEC and LASER adjust not selected TEC Display showing actual temperature LASER DISPLAY enabled in I mode Constant T mode selected LASER display...

Страница 31: ...the LASER Output off ILX also recommends that the connections to the LDC 3700C Series Laser Diode Controller output be made using twisted wire pairs with an earth grounded shield see Figure 2 1 on pa...

Страница 32: ...d they be jostled or bumped Figure 2 1 Laser Diode Connection Configurations Bias 3700B Series Laser Diode Controller OUTPUT 7 6 9 5 3 P D L D Earth Ground Bias 3700B Series Laser Diode Controller OUT...

Страница 33: ...k Panel LD Connector Interlock Connections In order for the laser output to be enabled a short must exist between the Interlock pins pins 1 and 2 of the connector The short can be a direct short acros...

Страница 34: ...is optional Setting the PD bias The LDC 3700C Series Laser Diode Controller provides an adjustable reverse bias of 0 5 VDC for the photodiode To set the photodiode bias to 5 volts reverse bias turn t...

Страница 35: ...in pairs internally to allow high current flow to the TEC module Peltier device Pins 7 and 8 are connected to the sensor i e thermistor Pins 9 through 15 are normally not used and should be left uncon...

Страница 36: ...ction with the appropriate enunciator illuminated Operating a Laser in Constant Current I Mode Suppose you have an LDC 3724C Laser Diode Controller and you want to run the instrument in Constant Curre...

Страница 37: ...R DISPLAY parameters When the LASER DISPLAY SET switch is pressed a display set point value is indicated by the corresponding display mode enunciator flashing At this point the Controller is in Consta...

Страница 38: ...ent of the set point and the controller mode Constant Current or Constant Power Set Current Source Limit To set the current source limit use the SELECT push button in the PARAMETER LASER section of th...

Страница 39: ...en press the LASER DISPLAY V push button The LASER display will then indicate the LASER voltage limit setting While holding the PARAMETER SET push button adjust the voltage limit using the adjust knob...

Страница 40: ...hanges due to internal or environmental conditions the controller will increase decrease the current to the laser to maintain the power set point The following paragraphs detail the instrument configu...

Страница 41: ...oint values The display annunciator mW will illuminate when PPD is selected Adjust the Constant Power set point of the controller to 1 00 mW To do this set the instrument to LAS mode by pressing the a...

Страница 42: ...hed release the SET push button to store the new limit value The LIM P is the absolute limit of optical power as detected by the unit via the monitor PD feedback loop In order for this limit to be mea...

Страница 43: ...Panel 04_09 LDC 3700C Series 27 C H A P T E R 2 the laser The Controller s laser source will drive the laser to the Constant Power set point and maintain closed loop control with the PD current measu...

Страница 44: ...ashes at 1 Hz Open circuit Output off OPEN CIRCUIT light flashes at 1 Hz If this condition was caused by an excessively high compliance voltage the VOLTAGE LIMIT light will also be turned on Output sh...

Страница 45: ...ection with the appropriate enunciator illuminated In the case of the temperature sensor constants the LASER display section displays which constant you are viewing or adjusting C1 C2 or C3 and the TE...

Страница 46: ...ndicated on the TEC display Note Note for RTD sensors the RTD Temperature Sensor Converter option is required ILX Model 599 Table 2 2 shows the SENSOR SELECT positions and corresponding position code...

Страница 47: ...on the LASER display and the value will be displayed on the TEC display To adjust the value of C1 C2 or C3 press the PARAMETER SELECT button until it sequences to CONST on the TEC side The CONST indic...

Страница 48: ...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...

Страница 49: ...display will flash The TEC current limit is displayed in Amps Note it is normal for the TE Current limit to be reached when the TEC output is first turned on Typically the TE current will be maximum...

Страница 50: ...t mode indicated by the display enunciator flashing Before adjusting the set point check the TEC display for proper display mode The display mode determines which set point is being adjusted Adjust th...

Страница 51: ...tant TE current mode In this mode the temperature controller will output a constant current when the output is enabled regardless of temperature The output will only be disabled by manually turning th...

Страница 52: ...s in a controller action as shown in the following table Table 2 3 TEC Error Indicators Error Condition Action Temperature limit TEMP LIMIT light flashes at 1 Hz Open sensor Output off SENSOR OPEN ind...

Страница 53: ...Temperature mode thermistor constants C1 C2 and C3 a temperature set point of 35 C a loop gain of 30 temperature limit of 40 C and a TE current limit of 2 A Once this set up is saved the LDC 3700C Con...

Страница 54: ...point is to the operating voltage of your laser the faster the circuit will work in the event of an open circuit Some experimentation may be necessary for optimum results Using the LDC 3700C Controll...

Страница 55: ...ange high bandwidth mode with a limit of 175 mA The allowable bandwidth of the modulated signal defined as the 3 dB roll off point is dependent on the LDC 3700C Series family member the LASER current...

Страница 56: ...mode To accomplish setting the current source limit use the SELECT push button in the PARAMETER LASER section of the front panel to select LIM I You will notice there are two LIM I selections one in...

Страница 57: ...ming lit To disable the output press the OUTPUT push button again Boosting the TE Controller For users who need more than 16 Watts of TE Controller power a booster current source may be required and t...

Страница 58: ...e LDC 3700C Series instrument Pin 13 is used as an external shutoff switch Although it is labeled as Temp Limit its function is to shut off the TEC controller This function is controlled by applying a...

Страница 59: ...o you may only query the TEC voltage via remote control The following sections show you the fundamentals of operating your LDC 3700C Laser Diode Controller remotely through the USB or GPIB interface U...

Страница 60: ...ontent data is often called a device dependent message or a device dependent command Interface messages manage the bus with functions such as initializing the bus and addressing or unaddressing device...

Страница 61: ...t all data and messages are reliably transferred NRFD not ready for data indicates whether a device can receive the next byte of data or message NDAC not data accepted indicates whether a receiving de...

Страница 62: ...t is necessary to change the 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...

Страница 63: ...ng the LOCAL switch returns the instrument to LOCAL control mode unless the Local Lockout state has been activated by the host computer Local Lockout disables all LDC 3700C Series Laser Diode Controll...

Страница 64: ...identify optional letters The optional letters must be in the correct sequence Some examples of what works and what does not White Space White space is normally the space character space bar A single...

Страница 65: ...same command string if you separate them with a semicolon The semicolon can be preceded by one or more spaces Examples TEC DIS 1 tec set t TEC MODE t TEC T 25 TEC Const 1 2 3 5 TEC OUT 1g1 Parameters...

Страница 66: ...d For example TEC CONST 1 111 0 456 A query has no space between the mnemonic and the question mark as in LAS LDI Command Tree Structure Many of the LDC 3700C remote commands require a compound struct...

Страница 67: ...fore the question mark in a query command root com cmds CAL CLS DELAY ERR MES MES RAD RAD SECURE TERM TERM TIME TIMER COND DEC DIS DIS EVE LDI LDI INC MDI MDI MODE OUT OUT MDP MDP STEP STEP TOL TOL CA...

Страница 68: ...engineering scientific notation There are no default values for omitted parameters Some device dependent commands are compound commands in which the first mnemonic opens a path to a set of commands r...

Страница 69: ...h PSC 1 on 0 off RCL 0 to 10 see front panel RECALL function SAV 1 to 10 see front panel SAVE function ESE 0 to 255 see Figure 3 2 SRE 0 to 255 see Figure 3 2 and PUD used at factory only A list of al...

Страница 70: ...rrent source limit high range for 3744C LAS LIM I4 1 Used to set the LASER current source limit high range for 3744C LAS LIM I5 1 Used to set the LASER current source limit low range for 3714C high ra...

Страница 71: ...not reset until the Event Register is queried or the LDC 3700C Series Laser Diode Controller is powered off Conditions reflect the current state of the device and therefore may change many times duri...

Страница 72: ...depend on the completion of all previous commands For example the user may set the TEC output to 30 C enable an SRQ on Operation Complete set ESE 1 and SRE 32 and have an SRQ handling routine in the u...

Страница 73: ...RE M O T E O P E R A T I O N Command Syntax 04_09 LDC 3700C Series 57 C H A P T E R 3 Figure 3 5 Status Reporting Scheme...

Страница 74: ...However their outputs are not reported in the Status Byte Register Rather they go to the hardware which controls the output switching for that function LASER or TEC The events and conditions which ma...

Страница 75: ...r Limit output on 11 TEC High Temperature Limit Condition 4 N A 12 N A 5 N A 13 N A 6 N A 14 N A 7 N A 15 N A 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 15 14 13 12 11 10 8 9 10 11 12 13 14 15 9 8 Logical OR Tur...

Страница 76: ...8 Sensor Type Change while output on Eve 1 TEC Voltage Limit 9 Outside of TEC Tolerance Cond 2 N A 10 Sensor Shorted while output on Cond 3 High Temperature Limit 11 N A 4 N A 12 N A 5 Booster Change...

Страница 77: ...manner except the DELAY command which is sequential The operation complete flag is set after the conditions outlined in the Operation Complete Definition have been satisfied The 04_09 common command i...

Страница 78: ...RE M O T E O PE R A T I ON Command Syntax 62 LDC 3700C Series C H A P T E R 3...

Страница 79: ...nto two parts The first part contains an overview of the remote commands used by the LDC 3700C Series Laser Diode Controller The second part contains all of the LDC 3700C Series Laser Diode Controller...

Страница 80: ...rrent calibration mode LAS CAL LDI NONE Returns the ready state for entering the laser current calibration value LAS CAL LDV NONE Used to enter the laser voltage calibration mode LAS CAL LDV NONE Retu...

Страница 81: ...range for 3714C 3744C LAS LIM I1 NONE Used to return the LASER current source limit low range for 3714C 3744C LAS LIM I2 1 Used to set the LASER current source limit low range for 3724C LAS LIM I2 NO...

Страница 82: ...ime period value LAS TOL NONE Used to return the LASER set point tolerance value and time period value MES 1 Used to enter a string message of up to 16 bits MES NONE Returns a previously stored ASCII...

Страница 83: ...eturns status of temperature display on off TEC ENAB COND 1 Sets the enable register for TEC conditions TEC ENAB COND NONE Returns the value of the TEC conditions enable register TEC ENAB EVE 1 Sets t...

Страница 84: ...point TEC T NONE Returns the TEC measured temperature value TEC TOL 1 or 2 Used to set the TEC set point tolerance value and time period value TEC TOL NONE Used to return the TEC set point tolerance v...

Страница 85: ...ore enabling service requests SRQ Example CLS Action 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 th...

Страница 86: ...sured temperature Action Enables bits in the standard event status enable register Response The value must be between 0 and 255 Bit Reference Notes Bit 5 of the status byte register is set if any enab...

Страница 87: ...Notes Bit 5 of the status byte register is set if any enabled conditions are true Response is the sum of the enabled bits ESE Event Status Enable COMMON DEVICE DEPENDENT FRONT PANEL 0 Operation Compl...

Страница 88: ...sponse is the sum of the enabled bits This command allows you to determine which type of error has occurred ESR Standard Event Status Register COMMON DEVICE DEPENDENT FRONT PANEL 0 Operation Complete...

Страница 89: ...self Response Returns a comma delimited standard format ASCII identification string from information stored in the instrument during manufacture The LASer CALMD command sets the laser s photodiode fee...

Страница 90: ...se only The LASer CAL LDI command is used to enter the LASER current set point measurement and limit in low bandwidth mode calibration mode Parameters None Notes Since the limit circuit is the same fo...

Страница 91: ...LDC 3700C Series Laser Diode Controller is ready for the user to enter a value Examples Las CAL Ldv action the LDC 3700C Series Laser Diode Controller enters calibration mode for LASER voltage Las Ca...

Страница 92: ...to enter a value via the LASer MDI command Examples Las CAL MDI action the LDC 3700C Series Laser Diode Controller enters the LASER photodiode current calibration mode LAS Cal MDI action the LDC 3700C...

Страница 93: ...refore 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...

Страница 94: ...ng The minimum time to complete one decrement is about 20 msec Therefore values for the second optional parameter time between decrements have a practical minimum of 20 Examples LAS MODE I LAS STEP 3...

Страница 95: ...e LAS DISPLAY I switch Notes In local operation the status of the I switch is indicated by the enunciator next to the LASER display mA will be illuminated when the display is in I mode Examples LAS DI...

Страница 96: ...is turned off automatically when another LASER DISPLAY selection is enabled Examples LAS DIS MDI action enables the LASER display for photodiode current values Laser Disp Mdi action enables the LASER...

Страница 97: ...switch is not currently active laser photodiode monitor power is not displayed Las dis MDP response 1 means that the LASER DISPLAY PPD switch is currently active PD power may be displayed The LASer DI...

Страница 98: ...cted mode LDI MDI IPD or MDP PPD LAS Dis Set action enables the LASER display for the set point of the selected display mode The LASer DISplay SET query returns the status of the LASER DISPLAY SET swi...

Страница 99: ...s they were at power down unless the power on status clear flag is set true for more information see the PSC definition in the IEEE488 2 specification Examples LAS ENAB COND 129 action enables the LAS...

Страница 100: ...ta State 16 Interlock Disabled 4096 N A 32 N A 8192 N A 64 N A 16384 N A 128 Open Circuit 32768 N A Notes The enabled LASER conditions can be set by using the LASer ENABle COND command The LASER condi...

Страница 101: ...flag is set true for more information see the PSC definition in the IEEE488 2 specification Examples LAS ENAB EVENT 136 action enables the LASER status event register so that the Open circuit and Powe...

Страница 102: ...off state change and Interlock changed LASER events will be reported in summarized form to the status byte register bit 2 Radix Hex Las Enab Eve response HF9B means that all of the above events will...

Страница 103: ...n the IEEE488 2 specification The factory default value for this register is B0000100000001000 or H808 or 2056 decimal Examples LAS ENAB OUTOFF 9 action enables the LASER status outoff register so tha...

Страница 104: ...he 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...

Страница 105: ...arameter is entered as zero LAS INC 0 the command will do nothing The minimum time to complete one increment is about 20 msec Therefore values for the second optional parameter time between increments...

Страница 106: ...ion enters a value of 1 025 volts The LASer LDV query returns the value of the measured laser voltage Notes This measurement is updated approximately once every 600 msec Examples LAS ldv response 3 03...

Страница 107: ...which represents the LASER limit current in mA Notes The current limit is in effect in all modes of operation of the laser output with respect to the output range low high Examples LAS LIM I2 180 act...

Страница 108: ...on the LDC 3744C Not applicable for LDC 3724C or LDC 3714C Notes The current limit is valid for all modes of Laser operation Examples LAS LIM I3 response 400 means the laser current limit is 400 mA L...

Страница 109: ...ith respect to the current output range In local operation the limit current is entered by selecting LIM I parameter pressing and holding in the PARAMETER SET switch adjusting the ADJUST knob until th...

Страница 110: ...s the monitor PD power limit is set to 3 0 mW LAS Limit MDP response 10 0 means the monitor PD power limit is set to 10 0 mW The LASer LIMit V command sets the LASER compliance voltage limit value Par...

Страница 111: ...e 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 Examples Las Mdi 40 action The LASER output is controlled so that the ph...

Страница 112: ...his measurement is updated approximately once every 600 msec Examples Las Mode MDP Las Calmd 460 Las MDp response 100 0 means 100 mW of photodetector power This feedback is controlling the laser curre...

Страница 113: ...the output low bandpass filter Examples LAS MODE ILBW action sets the laser output for constant I mode low bandwidth The LASer MODE MDP command selects laser constant power mode Parameters None Notes...

Страница 114: ...n the LASER output is off it is safe to connect or disconnect devices to the LASER output terminals When the LASER output is off an internal short is placed across the output terminals This condition...

Страница 115: ...0 mA LDC 3714C only or 1000 mA LDC 3744C only The LASer RANge query returns the value of the Laser Drive Current range Notes The resolution and accuracy of the laser limit current are dependent on the...

Страница 116: ...ns the laser monitor PD feedback set point is 10 0 mW CALPD 0 Laser Set MDP response 25 0 means the laser monitor PD feedback set point is 25 0 mW CALPD 0 The LASer STEP command is used to increment o...

Страница 117: ...ts the LASER current tolerance in mA with a range of 0 1 to 100 0 mA and the second represents the time window in seconds with a range of 0 001 to 50 000 seconds Notes The LDC 3700C Series Laser Diode...

Страница 118: ...eful for storing messages which relate to a test or configuration Parameters An ASCII string that is 1 16 bytes in length Notes The message may contain any ASCII character but will be terminated when...

Страница 119: ...Status Enable Service Request Enable Event Status Enable Standard Event Status Enable Factory default condition disabled In the disabled state the values of the enable registers are saved through pow...

Страница 120: ...able See Chapter Three for more information on register structure Example PSC Request state of power on status clear flag Action Stores data unique to the instrument such as calibration date and seria...

Страница 121: ...also be used with Hex H binary B or octal O 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 Examples RAD...

Страница 122: ...Sets OQIS state Notes OCIS Operation complete Command Idle State This is the same state as after OPC no further operations to complete OQIS Operation complete Query Idle State This is the same state...

Страница 123: ...e request enable register condition summary and error message bits are enabled 8 128 136 Action Requests the value in the status byte register Notes Response is the sum of the enabled bits See Chapter...

Страница 124: ...troller enters calibration mode for current Tec Cal Ite action the LDC 3700C Series Laser Diode Controller enters calibration mode for current The TEC CAL ITE query is used to determine that the LDC 3...

Страница 125: ...Tec Cal Sensor action the LDC 3700C Series Laser Diode Controller enters calibration mode for the sensor which is selected by the back panel switch The TEC CAL SENsor query is used to determine that t...

Страница 126: ...calibration mode The TEC CAL V query is used to determine that the LDC 3700C Series Laser Diode Controller is ready for a value to be entered during the calibration cycle of the TEC CAL V mode Notes...

Страница 127: ...was 9 999 to 9 999 However for a thermistor sensor these values are scaled by the appropriate exponential value for the Steinhart Hart equation Notes If less than three parameters need to be changed...

Страница 128: ...nrf value 1 on 0 off Notes Turning the TEC display and LEDs off means that a message of all blank spaces is sent to the TEC display and all of the TEC section s indicator LEDs will be turned off Examp...

Страница 129: ...led TEC output current is not displayed Tec DISp Ite response 1 means that the TEC DIS ITE switch is enabled TEC current may be displayed The TEC DISplay PARAM command enables the TEC display to show...

Страница 130: ...ff Examples TEC Dis R response 0 means that the TEC DIS R switch is not active Therefore TEC thermistor resistance or AD590 current or LM335 voltage is not displayed Tec dis R response 1 means that th...

Страница 131: ...to show the TEC load temperature measurement Parameters None Notes The actual TEC T display is turned off automatically when another TEC display selection is enabled Examples Tec Dis T action enables...

Страница 132: ...lues 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...

Страница 133: ...response 129 means that the TE Module Open and TE Current Limit conditions may be reported in the status byte register Radix Hex TEC Enable Cond response H0EFB means that any and all of the above con...

Страница 134: ...ear 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 will be reported in summarized...

Страница 135: ...ure Limit and Output Out of Tolerance TEC events will be reported in summarized form to the status byte register bit 0 Radix Hex TEC Enab Eve response H0EFB means that all of the above events will be...

Страница 136: ...E 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 en...

Страница 137: ...nab Outoff response H17FB means that all of the above conditions will cause the TEC output to be turned off Radix Bin TEC Enab Outoff response B1001 means that the High Temperature Limit and TE Curren...

Страница 138: ...o the nearest of 1 3 10 30 100 or 300 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 wi...

Страница 139: ...econds 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 TEC MODE ITE Tec Ite 3 5 actio...

Страница 140: ...ponse 3 5 means the TEC output current limit is 3 500 amps Tec Limit Ite response 4 0 means the TEC output current limit is 4 000 amps The TEC LIMit THI command sets the TEC high temperature limit val...

Страница 141: ...4 7 C The TEC MODE query returns the selected TEC control mode Notes The TEC mode is also the parameter which is controlled The TEC output is kept at the set point Examples Tec MODE response ITE means...

Страница 142: ...selects TEC constant temperature control mode 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...

Страница 143: ...rmistor resistance to 20 5 k or sets the AD590 current to 20 5 A or sets the LM335 voltage to 20 5 mV TEC Mode R TEC R 10 action sets the set point thermistor resistance to 10 0 k or the AD590 current...

Страница 144: ...SOR SELECT switch is in the 100 A thermistor posi tion Tec SEN response 3 means the LM335 sensor is selected by the back panel SENSOR SELECT switch The TEC SET ITE query returns the TEC constant TE cu...

Страница 145: ...see TEC LIMit THI on page 124 this limit becomes the maximum set point value as well Examples Tec T 20 action sets the TEC temperature set point to 20 0 C TEC MODE T TEC T 25 3 action sets the TEC tem...

Страница 146: ...5 seconds Notes The LDC 3700C Series Laser Diode Controller defaults to a tolerance of 0 2 C for 5 seconds unless changed by the TEC TOLerance command In R mode the temperature and time parameters ar...

Страница 147: ...age value for calibration mode Parameters An nrf value which represents a TEC voltage calibration value Notes If the user attempts to use this command when not in TEC voltage calibration an error E 41...

Страница 148: ...tandard terminator has been altered to include a carriage return Notes An altered terminator will be in the form CR NL END This termination will be sent with all output until the TERM 0 command is sen...

Страница 149: ...onds since the last TIMER query was issued Action Performs internal self test then reports results Response 0 test completed with no errors Non zero test not completed or was completed with errors Exa...

Страница 150: ...C O M M A N D RE F E R E N C E Command Reference 134 LDC 3700C Series C H A P T E R 4...

Страница 151: ...NIST traceable measurement instrumentation and our calibration engineers and technicians use automated test equipment to accurately and efficiently capture and record calibration data An original cert...

Страница 152: ...1 0 C When necessary however the LDC 3700C Series Laser Diode Controller can be calibrated at its intended use temperature if this is within the specified operating temperature range of 0 50 C Finally...

Страница 153: ...alibration Overview 04_09 LDC 3700C Series 137 C H A P T E R 5 calibration circuit with the required components listed in Table 5 2 on page 138 Also the devices required for other calibration loads ar...

Страница 154: ...R TEMPERATURE CONTROLLER CALIBRATION Current Source Calibration all models 1 20W resistor low TCR TEC Voltage Calibration all models 50 5W resistor low TCR Thermistor 10 A setting 100 A setting 100 k...

Страница 155: ...perature Controller 15 pin connector on the rear panel sensor and sensor terminals 4 Enter the TEC sensor calibration mode by pushing the Communications LOCAL and TEC DISPLAY R switches at the same ti...

Страница 156: ...tore the new value into non volatile memory After the SET switch is released the LDC 3700C Series Laser Diode Controller will return to its former state before calibration LM335 Sensor Calibration The...

Страница 157: ...oint probe resistance measurement is recommended 3 Make sure that the TEC output is off before entering the ITE calibration mode Press the Communications LOCAL and TEC DISPLAY ITE switches at the same...

Страница 158: ...low range After calibration is complete in this range switch to the high range and repeat the procedure Configure the Laser Controller in the following state 1 Measure and record the resistance of a...

Страница 159: ...released the Controller will drive the LASER current output to about 25 of the first calibration set point 7 Calculate the measured current again through the load resistor 8 Press and hold in the PAR...

Страница 160: ...e of the ammeter Then place a calibrated DMM with 0 1 mV resolution to measure the voltage across the resistor R1 as shown in Figure 6 1 Calculate the current in the following steps by using Ohm s Law...

Страница 161: ...nal current For example if the first calibration set point was 4000 A the second set point will be about 1000 A 7 Press and hold in the PARAMETER SET switch and turn the ADJUST knob until the LASER di...

Страница 162: ...ions LOCAL and LASER DISPLAY V switches at the same time The TEC display will blank and the controller will drive the LASER current output to the respective set point and the LASER display will indica...

Страница 163: ...ermistor current sources so that the thermistor resistance measurement for these ranges will meet the stated accuracy specifications 1 Set the SENSOR SELECT switch back panel to the 100 A position the...

Страница 164: ...o its former state before calibration The OPC query may be used after the TEC R value is sent to determine when the calibration is completed LM335 Sensor Calibration The following procedure is for cal...

Страница 165: ...e accurately measured load resistance I is the calculated current in Amps A 4 point probe resistance measurement is recommended 3 The TEC output must be off in order to enter the ITE calibration mode...

Страница 166: ...ble and the Controller is ready to proceed enter the value by issuing the TEC V nrf value command where the actual TEC voltage on the DMM is the nrf value Once the actual TEC voltage value is entered...

Страница 167: ...range switch to the high range and repeat the procedure Configure the Controller in the following manner for the Laser Controller calibration 1 Measure and record the resistance of a 1 20 W resistor a...

Страница 168: ...alue is entered via the LAS LDI command the Controller will apply a new current equal to about 25 of the previous set current 7 Input the second actual measured LASER output current as an nrf value as...

Страница 169: ...its LASER Current Calibration mode The controller will increase the laser current output until the current at the PD monitor IPD inputs equals the targeted set point 4 After a few seconds the Controll...

Страница 170: ...V nrf value command The measured value of the voltage should not be entered until the LDC 3700C Series Laser Diode Controller is ready to receive it The Controller will be ready to receive the voltage...

Страница 171: ...er directly or through a switch If OPEN CIRCUIT indicator is lit check the load connections and then try again Check the OUTPUT ON switch the corresponding LED should be lit Output current at limit ca...

Страница 172: ...lit check the load connections Check that pins 14 and 15 of the output connector are not connected See Boosting the TE Controller on page 41 Power on but temperature is not controlled If SENSOR OPEN i...

Страница 173: ...e via GPIB clears the error queue Note Errors codes not listed are reserved for future design use Table 5 4 Error Code Classifications Error Code Range Area of Operation E 001 to E 099 Internal Progra...

Страница 174: ...l error disabled output E 412 Analog section status is all 1 s or all 0 s power down E 413 Serial EEPROM checksum error E 415 Sensor short disabled TEC output E 416 E 419 Incorrect Configuration for C...

Страница 175: ...Diode must have the output on and the responsivity set to zero to start E 519 Setting a measurement is only valid during the calibration phase for that measurement User has tried to calibrate a measu...

Страница 176: ...C A L IB R A TI O N A N D TR OU BL E S HO O T IN G Troubleshooting 160 LDC 3700C Series C H A P T E R 5...

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