Stanford Research Systems LDC500 Operation And Service Manual Download Page 9

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General Information

vii

Notation

The following notation will be used throughout this manual.

Unless otherwise speciﬁed in the text, LDC500 refers generally to
either the LDC500, LDC501, or LDC502 Laser Diode Controller.

A warning means that injury or death is possible if the instructions

WARNING

are not obeyed.

A caution means that damage to the instrument or other equipment

CAUTION

is possible.

Typesetting conventions used in this manual are:

•

Front-panel buttons are set as [Button].

•

Front-panel indicators are set as

Overload

•

Remote command names are set as

*IDN?

•

Literal text other than command names is set as

OFF

Remote command examples will all be set in monospaced font. In
these examples, data sent by the host computer to the LDC500 are set
as

straight teletype font

, while responses received by the host

computer from the LDC500 are set as

slanted teletype font

LDC500 Series Laser Diode Controllers

Summary of Contents for LDC500

Page 1: ...Operation and Service Manual Laser Diode Controllers LDC500 Series Stanford Research Systems Revision 4 3 February 23 2016...

Page 2: ...urned to a Stanford Research Systems authorized service facility Contact Stanford Research Systems or an authorized representative before returning this product for repair Information in this document...

Page 3: ...terminal 1 6 1 4 3 Turning on power 1 6 1 4 4 Hardware reset 1 8 1 5 Cable Interfaces 1 8 1 5 1 Modulate 1 8 1 5 2 Sync 1 8 1 5 3 Laser diode 1 8 1 5 4 TEC 1 9 1 5 5 Remote interface connections 1 10...

Page 4: ...ode 2 15 2 3 4 Operating the laser in CP mode 2 16 2 3 5 Modulation 2 17 2 3 6 Monitoring the LD 2 17 2 3 7 Optical power calibration 2 18 2 3 8 Con guring LD trip o s 2 18 2 4 Factory Default Setting...

Page 5: ...Status commands 4 52 4 6 Status Model 4 57 4 6 1 Status byte SB 4 58 4 6 2 Service request enable SRE 4 59 4 6 3 Standard event status ESR 4 59 4 6 4 Laser diode condition LDCR 4 60 4 6 5 TEC controll...

Page 6: ...lts 5 6 5 2 5 Thermal runaway 5 6 5 2 6 Polarity change locked out 5 6 5 3 Other messages 5 6 5 3 1 Restart 5 6 6 Accessories 6 1 6 1 Cables 6 2 6 1 1 Laser diode cables 6 2 6 1 2 TEC cables 6 4 LDC50...

Page 7: ...SELECTOR set for the wrong AC line voltage or if the wrong fuses are installed Verify that the correct line fuses are installed before connecting the line cord Fuse size is 5MF fast blow 5 20 mm For...

Page 8: ...n SRS Products Symbol Description Alternating current Caution risk of electric shock Frame or chassis terminal Caution refer to accompanying documents Earth ground terminal Battery Fuse On supply Off...

Page 9: ...ent or other equipment CAUTION is possible Typesetting conventions used in this manual are Front panel buttons are set as Button Front panel indicators are set as Overload Remote command names are set...

Page 10: ...term stability 1 hr 5 ppm FS Long term stability 24 hr 15 ppm FS Noise density 1 high range 0 7 3 5 12 5 low range 0 4 1 8 6 3 nA Hz typ Wide band noise 2 high range high BW 0 9 4 5 25 high range low...

Page 11: ...utput TTL pulse width negative 10 s Delay 6 0 004 1000 s Measurement display LD current resolution 1 10 100 A accuracy 200 ppm FS PD current resolution 0 1 A accuracy 200 ppm FS LD voltage resolution...

Page 12: ...ty Thermal drift 2 0 0005 C C Short term 1 hr 0 001 Long term 24 hr 0 002 C Control algorithm digital PID Autotuning method open loop step response TEC current control Output range 4 5 4 5 A Output po...

Page 13: ...cuitry inside the instrument Sensor uncertainty is not in cluded which can add up to 2 C 2 Measured by a monitor thermistor on the TEC stage The LDC500 is operated in an environmental chamber between...

Page 14: ...xii General Information LDC500 Series Laser Diode Controllers...

Page 15: ...1 5 1 3 Features and controls 1 6 1 4 Power 1 6 1 4 1 Power entry module 1 6 1 4 2 Grounding terminal 1 6 1 4 3 Turning on power 1 6 1 4 4 Hardware reset 1 8 1 5 Cable Interfaces 1 8 1 5 1 Modulate 1...

Page 16: ...high stability output with programmable current and voltage limits The temperature controller operates with most commonly used tem perature sensors and thermoelectric coolers TEC to maintain pre cisio...

Page 17: ...simpli ed or 1000 mA and 2000 mA LDC502 For both ranges there are two control modes for the magnitude of the current source output con stant current CC and constant optical power CP A simpli ed circui...

Page 18: ...n of the LDC500 delivers high performance temperature control for thermally stabilizing the laser diode Most commonly used thermal sensors are supported including thermis tors RTDs LM335 class voltage...

Page 19: ...stand all potential ground paths in your system to avoid inadvertant ground loops or short circuits The monitor photodiode if any will perform best if also left oating or one terminal can be tied to o...

Page 20: ...r explains each part of the front and rear panel of the LDC500 Circled numbers in the left margin refer to Figure 1 4 1 4 Power 1 4 1 Power entry module A rear panel power entry module contains a stan...

Page 21: ...1 4 Power 1 7 1 7 8 9 10 2 3 4 5 6 11 12 13 14 15 17 18 16 Figure 1 4 The LDC500 front and rear panels LDC500 Series Laser Diode Controllers...

Page 22: ...10 V inputs to mod ulate the laser diode operating point In CC mode the scale factor is 2 either 25 mA V when on the 250 mA current range or 50 mA V on the 500 mA current range When operating in CP m...

Page 23: ...on between pins 1 and 2 for the laser to operate Neither of these pins may be allowed to contact ground or any other signal See Figure 2 2 in section 2 1 2 for further examples 1 5 4 TEC TheDB 15femal...

Page 24: ...5 5 Remote interface connections An IEEE 488 GPIB interface is standard on all LDC500s The GPIB address can be con guredfrom the Utility menu see section 3 4 1 4 16 The default GPIB address is 2 An RJ...

Page 25: ...action and the state of the TEC is indicated by the TEC ON lamp 1 6 1 4 TEC control mode The principal control mode of the TEC either CT or CC is controlled by the Temp Current button under the TEC Co...

Page 26: ...n associated with the new menu For instance to jump from the LD voltage monitor menu LD to the TEC temperature setpoint menu simply press the Set button under the TEC Control block Pressing the Monito...

Page 27: ...ing point of the instrument To turn on this real time entry press the Live Entry button adjacent to the wheel If the Live indicator illuminates then the wheel is now in real time mode and continuously...

Page 28: ...1 14 Overview Note that if the Utility Local button is pressed when REM is not illuminated the Utility menu tree will be selected LDC500 Series Laser Diode Controllers...

Page 29: ...ings 2 7 2 2 3 Verify TEC wiring polarity 2 8 2 2 4 Auto tuning 2 9 2 2 5 TEC operation in CT mode 2 10 2 2 6 Thermal runaway 2 10 2 2 7 TEC operation in CC mode 2 11 2 2 8 TEC limit values 2 11 2 2 9...

Page 30: ...rounded through the CHASSIS GND lug on the rear panel Chassis ground should be tied to earth before any further connections are made 2 1 2 Laser diode connections Figure 2 2 shows the proper connectio...

Page 31: ...isconnected If possible better results will be obtained by connecting pin 14 to pin 7 and pin 15 to pin 8 ideally as close to the sensor as practical Some improvement is still obtained even if the con...

Page 32: ...2 13 14 15 TE Sense V TE TE TE Sense t Sensor 2 Wire Sensor 4 Wire Sensor 4 Wire Sensor 2 Wire NTC RTD LM335 LM235 LM135 10 mV K AD590 AD592 TMP17 1 A K Excitation Figure 2 3 Wiring diagram for the TE...

Page 33: ...ds and then return to low speed mode The fan speed is automatically controlled and will increase when power dissipation in the LDC500 is signi cant The display will show the instruments serial number...

Page 34: ...pendent of the temperature reading Assuming you have a laser stage with a TEC module and temperature sensor select CT mode 2 2 1 Sensor con guration Press the Con g button to navigate to the TEC con g...

Page 35: ...ower temperature limits the TEC voltage limit and the TEC current limit Begin by pressing the Set button to navigate to the TEC Settings menu tree Press the button repeatedly to reach the top of the m...

Page 36: ...ue around 10 of the maximum current Be sure to press Enter to complete the entry Press the TEC Monitor button The temperature display should reappear on the alphanumeric display Press the TEC On O but...

Page 37: ...set previously If a di erent current step is desired for autotuning press to Autotune tuneStep and change the setting to the desired step size in amperes Press to navigate back to the Autotune start i...

Page 38: ...ess Enter The TEC controller will adjust the output current and settle the temperature to the new setting Temperature can also be adjusted in live tracking mode Press the Live Entry button to enter li...

Page 39: ...TEC controller is o pressing the Temp Current button tog gles the operating mode between CT and CC In CC mode press the TEC Set button and navigate to the top of the menu tree with to reach the TE I i...

Page 40: ...Under certain limit conditions it is important to shut down the TEC controller output To customize which events will lead to TEC shut down press the TEC Con g button and then press until you reach th...

Page 41: ...e goes below Tmin set Trip OFF at Tmin to Y To shut down when there is a sensor fault set Trip OFF at SensFault to Y Note that in CT mode a sensor fault will always shut down the TEC controller For mo...

Page 42: ...ur laser diode Con gurations include output current range working bandwidth photodiode bias voltage and responsivity and more Press repeatedly to reach the top of the menu tree Press 0 to select low r...

Page 43: ...ser diode The LD driver will uncondition ally shut down if the operating voltage on the laser diode ever exceeds this value Press repeatedly to return to LD I Now you may enter the desired operating c...

Page 44: ...liwatt units set use mW to Y to control the laser in raw mi croamperes of photodiode current set use mW to N For this example select N Press to select PD Bias and set the photodiode reverse bias betwe...

Page 45: ...in the LD Cfg menu tree reached by the Con g button is set to Y The front panel BNC input accepts 10 V inputs which imposes a modulation on the laser current in addition to the DC setpoint See the sp...

Page 46: ...ft slightly during calibration Make sure the LD driver is ON preferably in CP mode with PD units use mW set to N or else in CC mode Adjust the LD output so that a good stable optical power read ing ca...

Page 47: ...ure goes above Tmax set Trip o at Tmax to Y Note that this condition can operate indepen dent of the TEC controller and even operate if there is no TEC module However if enabled a sensor fault will al...

Page 48: ...s A not mW PD bias 2 5 V Photodiode reverse bias PD resp 1 A mW Photodiode responsivity CC CP lock no CC CP transitions allowed Trip o LD Ilim no Do not trip o when laser current limit is reached Trip...

Page 49: ...second Derivative gain Auto tune step 0 225 A Step size for autotuning CC CT lock no CC CT transitions allowed Trip o TE Ilim no Do not trip o when TEC current limit is reached Trip o TE Vlim YES Trip...

Page 50: ...2 22 Getting Started LDC500 Series Laser Diode Controllers...

Page 51: ...nel In This Chapter 3 1 Menu Navigation 3 2 3 2 Laser Menus 3 2 3 2 1 LD settings 3 2 3 2 2 LD monitor 3 4 3 2 3 LD con guration 3 5 3 3 TEC Menus 3 7 3 3 1 TEC settings 3 7 3 3 2 TEC monitor 3 8 3 3...

Page 52: ...the and buttons Figure 3 1 The menu navigation buttons 3 2 Laser Menus The three menu trees described here are all accessed by pressing the Parameter buttons under the Laser Diode Control block of the...

Page 53: ...e with PDMW Y 3 2 1 4 Laser current limit LD Settings LD lim SILM 4 18 3 2 1 5 Photodiode current limit LD Settings D lim PILM 4 19 Only visible with PDMW N 3 2 1 6 Photodiode power limit LD Settings...

Page 54: ...ntrol Note that monitor selections are read only and cannot be set Figure 3 3 The LD monitor menu selection 3 2 2 1 Laser operating current LD RILD 4 22 3 2 2 2 Photodiode current LD RIPD 4 23 3 2 2 3...

Page 55: ...ted by pressing the Con g button under Laser Diode control Figure 3 4 The LD con guration menu selection 3 2 3 1 Output range LD 3 4 6 RNGE 4 24 3 2 3 2 Modulate Enable LD 7 48 MODU 4 24 3 2 3 3 Modul...

Page 56: ...ivity LD RESP 4 27 3 2 3 8 Control mode locking LD 1 48 SMLK 4 28 3 2 3 9 Laser trip off con guration Several conditions can be enabled to trip o the laser current source LD ABB 48 AILM 4 29 LD ABB 48...

Page 57: ...C settings menu tree is selected by pressing the Set button under TEC Control block Figure 3 5 The TEC settings menu selection 3 3 1 1 Temperature setpoint TEMP 4 34 Only displayed in CT mode 3 3 1 2...

Page 58: ...yed without a sensor model 3 3 1 8 Minimum resistance 3 H 1F TRMN 4 33 Only displayed without a sensor model 3 3 1 9 TEC voltage limit I TVLM 4 32 3 3 2 TEC monitor The TEC monitor menu tree is select...

Page 59: ...3 3 2 3 Temperature reading IH d TTRD 4 35 3 3 2 4 Raw thermometer reading 3 HG01F TRAW 4 35 3 3 3 TEC con guration The TEC con guration menu tree is selected by pressing the Con g button under TEC c...

Page 60: ...the calibration model is set to BETA TE Cfg 3800 000K TNTB 4 43 3M 6 1F TNTR 4 42 d TNTT 4 43 3 3 3 4 Model parameters for NTC Steinhart Hart These items are only visible for NTC sensors when the cal...

Page 61: ...g is typically performed simply with the TUNE command For special situations requiring user control of the step size used to measure the thermal step response the TATS command is also available TUNE 4...

Page 62: ...ABB B 4C TTSF 4 45 3 3 3 10 TEC polarity The sense of the TEC current output polarity can be reversed for TE elements that are wired backwards so that positive current leads to heating of the stage T...

Page 63: ...left of the alphanumeric display Figure 3 8 The Utility menu selection 3 4 1 1 Save parameters Q P AP Q SPAR 4 48 3 4 1 2 Restore parameters Q 3 3 Q GPAR 4 48 3 4 1 3 IP address The numerical IP addr...

Page 64: ...9 P 4 6 U BLVL 4 49 3 4 1 8 Ethernet MAC address Q H 7 MACA 4 50 3 4 2 Other messages In addition to the menu selections described above the alphanumeric display may also display various error or stat...

Page 65: ...4 18 4 5 5 Laser setting commands 4 20 4 5 6 Laser monitor commands 4 22 4 5 7 Laser con guration commands 4 24 4 5 8 Laser trip o commands 4 29 4 5 9 TEC limit commands 4 31 4 5 10 TEC setting comma...

Page 66: ...Current Setpoint SIPD f 4 20 Photodiode Current Setpoint SWPD f 4 21 Photodiode Power Setpoint SCAN f i g 4 21 Multi step Scan of Laser Setpoint SYND h 4 22 Sync delay for scans Laser monitor RILD 4...

Page 67: ...34 TEC Current Setpoint TEMP f 4 34 TEC Temperature Setpoint TRTH f 4 34 TEC Resistance Setpoint TEC monitor TIRD 4 35 TEC Current Reading TVRD 4 35 TEC Voltage Reading TRAW 4 35 Raw Thermometer Readi...

Page 68: ...in Temperature TTVL z 4 46 TEC Trip o on Voltage Limit TTIL z 4 46 TEC Trip o on Current Limit Interface IDN 4 46 Identify TOKN z 4 47 Token Mode TERM z 4 47 Response Termination OPC 4 47 Operation Co...

Page 69: ...itive Transition LDNT i j 4 54 Laser Diode Negative Transition LDEV i 4 55 Laser Diode Event LDEN i j 4 55 Laser Diode Event Enable TECR i 4 55 TEC Condition TEPT i j 4 55 TEC Positive Transition TENT...

Page 70: ...o on Photodiode CP ATMN z 4 31 Laser Trip o on Min Temperature ATMX z 4 30 Laser Trip o on Max Temperature ATOF z 4 30 Laser Trip o on TEC O B BAUD z 4 49 Serial Baud Rate BIAS f 4 26 Photodiode Bias...

Page 71: ...eading RIPD 4 23 Photodiode Current Reading RNGE z 4 24 Laser Diode Current Range RVLD 4 23 Laser Diode Voltage Reading RWPD 4 23 Photodiode Power Reading S SCAN f i g 4 21 Multi step Scan of Laser Se...

Page 72: ...D z 4 36 TEC Control Mode TNTB f 4 43 NTC model Parameter TNTR f 4 42 NTC model R0 Parameter TNTT f 4 43 NTC model T0 Parameter TOKN z 4 47 Token Mode TPGN f 4 38 TEC Control Loop P Gain TPOL z 4 39 T...

Page 73: ...4 2 Alphabetic List of Commands 4 9 TVLM f 4 32 TEC Voltage Limit TVRD 4 35 TEC Voltage Reading U ULOC i 4 48 Unlock Ethernet LDC500 Series Laser Diode Controllers...

Page 74: ...n volatile memory Upon power on these settings are restored to their values before the power was turned o Where appropriate the default or power on value for parameters is listed in boldface in the co...

Page 75: ...ications with the LDC500 This example assumes a Windows based computer with HyperTerminal available for direct TCP IP connections 4 4 1 1 Network address con guration If the LDC500 is being connected...

Page 76: ...en the application begins it will ask you for a Connection Description Choose something like LDC ethernet and click OK When the Connect To window pops up choose the Connect us ing method as TCP IP Win...

Page 77: ...4 4 Ethernet 4 13 After clicking OK in the Connect To window you should see the following message from the LDC500 displayed by HyperTerminal LDC500 Series Laser Diode Controllers...

Page 78: ...der HyperTerminal Select File Properties and then click the Settings tab Press the ASCII Setup button to bring up the ASCII Setup window Select Send line ends with line feeds Echo typed characters loc...

Page 79: ...erface Finally send the ULOC 1 command see section 4 5 15 to enable the Ethernet interface for use Type ULOC 1 followed by the Enter key You can then test the interface for example by sending the IDN...

Page 80: ...rs are always required Do not send or or as part of the command Multiple parameters are separated by commas Multiple commands may be sent on one command line by separating them with semi colons so lon...

Page 81: ...for both set and query forms 4 5 3 Examples Each command is provided with a simple example illustrating its usage In these examples all data sent by the host computer to the LDC500 are set as straigh...

Page 82: ...ated but independent e ects Most importantly the output current is clamped by hardware to never exceed the SILM value under any conditions The second e ect is to limit the current setpoint value SILD...

Page 83: ...LD driver upon over voltage Users should be certain to set these important device protection parameters even when operating in CP mode Also in either control mode CC or CP the LD driver can optionally...

Page 84: ...urning the laser o via LDON OFF is immediate Front panel control is by the LASER On O button LDON ON Example Laser Diode Current Setpoint SILD f Set query the laser diode current setpoint to f in mA W...

Page 85: ...tep in mA if CP mode it is raw photodiode current step in A regardless of the value of PDMW The scan begins immediately after receipt of the SCAN command starting at the previous setpoint The second p...

Page 86: ...uired for a particular application consider the step size and the required tolerance For this requirement is given by e h where h is the SYND delay value This can be rearranged to give h ln For exampl...

Page 87: ...rent in A re gardless of control mode CC or CP optical power units PDMW or even laser current source on o Front panel LD RIPD Example 2003 021 Photodiode Power Reading RWPD Query the monitor photodiod...

Page 88: ...the maximum output current to 250 mA LDC501 or 50 mA LDC500 while RNGE HIGH sets it to 500 mA LDC501 or 100 mA LDC500 The RNGE command cannot be executed while the laser is on Front panel LD 3 4 6 RNG...

Page 89: ...te that by hardware design the measured laser current can never exceed the setpoint limit Front panel control is by the CC CP button Note that if the mode is switched from the front panel while the la...

Page 90: ...et to PDMW NO the CP mode display is A photodiode current Note that the value of PDMW has a subtle e ect on the photodiode setpoint parameters SIPD and SWPD and the limit values PILM and PWLM If PDMW...

Page 91: ...odiode Responsivity RESP f Set query the monitor photodiode responsivity to f in A mW The responsivity determines the conversion from photodiode current in A to optical power in mW The minimum possibl...

Page 92: ...uery the control mode lock out to z NO 0 YES 1 When SMLK YES is set the LDC500 will prevent the SMOD command from operating if the laser is on The front panel CC CP key is similarly inhibited Front pa...

Page 93: ...mode If the measured photodiode current or optical power exceeds the corresponding limit APLP YES causes the laser current source to shut down Note that this trip is implemented in rmware and can onl...

Page 94: ...own as well Front panel LD ABB A 4C ATOF YES Example Laser Trip o on Max Temperature ATMX z Set query the laser to trip o if the maximum temperature is ex ceeded to z NO 0 YES 1 If set to ATMX YES the...

Page 95: ...than TRMN in k If the sensor has a negative temperature coe cient this will correspond to the greatest temperature of the operating band not the lowest Front panel LD ABB 48 ATMN NO Example 4 5 9 TEC...

Page 96: ...upper user de ned tempera ture limits for normal operation If the user must assure the device is not operated below some minimum temperature for instance near the condensation point setting TMIN toge...

Page 97: ...ower bound on resistance regard less of whether the sensor has a negative or positive temperature coe cient Front panel 3 H 1F TRMN 9 50 Example Upper Resistance Limit TRMX f Set query the upper resis...

Page 98: ...1 234000E 00 TEC Temperature Setpoint TEMP f Set query the TEC temperature setpoint to f in C When the TEC is operated in CT mode the TEC current is adjusted by the control loop to maintain the senso...

Page 99: ...Query the TEC voltage in V Front panel G H TVRD Example 1 608900E 00 Raw Thermometer Reading TRAW Query the raw sensor value in k V or A depending on the sensor type Front panel 3 HG01F TRAW Example 1...

Page 100: ...set the present value of the TEC current is taken as the CC setpoint If the TEC is originally operating in CC mode and TMOD CT is set the present value of the temperature sensor is measured the CT set...

Page 101: ...es not stabilize at the beginning of the cycle the autotuning fails and the loop parameters remain unchanged If the step response cannot be interpreted successfully the autotuning also ends in failure...

Page 102: ...noisy setups Decreas ing TATS will reduce the temperature excursion during autotun ing which can improve recovery time after tuning as well as yield slightly improved temperature control Front panel...

Page 103: ...ers Note that in all cases D 0 Front panel P G TDGN Example 6 500000E 01 TEC Polarity Reverse Mode TPOL z Set query the TEC current polarity reverse mode to z NO 0 YES 1 When TPOL YES is set the LDC50...

Page 104: ...10 A and 1 mA Al ternately the user can specify a xed excitation current of 10 A NTC10UA 100 A NTC100UA or 1 mA NTC1MA The sensor type cannot be changed while the TEC is on and in CT control mode Fro...

Page 105: ...f no calibration coe cients are known or the user desires to operate in resistance control mode the model can be set to TMDN NONE Note that TMDN cannot be changed if the TEC is on and in CT mode TMDN...

Page 106: ...he Steinhart Hart model to f See TMDN for formula details Front panel 9 0 TSHB 2 347E 4 Example Steinhart Hart Coe cient C TSHC f Set query the C coe cient for the Steinhart Hart model to f See TMDN f...

Page 107: ...TC model to f in C See TMDN for formula details Front panel d TNTB 25 0 Example RTD Linear Model R0 Parameter TRTR f Set query the R0 parameter for the RTD model to f in k See TMDR for formula details...

Page 108: ...voltage TLMY sets the c coe cient in the calibration Front panel 0 d TLMY Example 2 731500E 02 AD590 Slope Parameter TADS f Set query the slope parameter for AD590 calibration to f in C A The AD590 ca...

Page 109: ...cause the TEC to shut down if the sensor TRAW value is greater than TRMX in k If the sensor has a negative temperature coe cient this will correspond to the lowest temperature of the operating band n...

Page 110: ...nt to the value set by TILM This limit can be reached during large temperature transitions when it essentially imposes a temper ature rate limit or at the ultimate cooling or heating limits of the the...

Page 111: ...onse messages terminated with the LF character while queries received on the ethernet interface shall generate response messages terminated by the CR and LF characters TERM settings are saved when the...

Page 112: ...r instrument settings except remote interface settings such as TCP IP address or baud rate There are 9 user records available for saving instrument setups numbered 0 8 Front panel Q P AP Q SPAR USER3...

Page 113: ...bled only a remote command returning the instrument to LOCK LOCAL or a power cycle will restore front panel control Note that any GPIB access to the LDC500 always places the instru ment into the LOCK...

Page 114: ...e left most byte of the mask Front panel Q 8 1 NMSK 1 255 NMSK 0 NMSK 1 NMSK 2 NMSK3 Example 255 255 0 0 Default Gateway GWAY i j Set query byte i of the internet default gateway to j Note that byte 0...

Page 115: ...the LDC500 to its default con guration The following commands are internally excecuted upon receipt of the RST command LDON OFF TEON OFF SVLM 5 0 SILM 20 0 LDC500 SILM 100 0 LDC501 PILM 5000 0 SILD 0...

Page 116: ...6 Status commands Status Byte STB i Reads the Status Byte register bit i STB Example 0 Service Request Enable SRE i j Set query the Service Request Enable register bit i to j SRE 0 1 Example Standard...

Page 117: ...Query the last execution error code A query of LEXE always clears the error code so a subsequent LEXE will return 0 Valid codes are Value De nition 0 No execution error since last LEXE 1 Illegal valu...

Page 118: ...Parameter bu er over ow 9 Bad oating point 10 Bad integer 11 Bad integer token 12 Bad token value 13 Bad hex block 14 Unknown token IDN Example LCME 4 The error 4 Illegal set is due to the missing La...

Page 119: ...TECR i Read the TEC Controller Condition Register bit i TECR 0 Example 1 TEC Positive Transition TEPT i j Set query the TEC Controller Positive Transition Register bit i to j TEPT 4 1 Example TEC Nega...

Page 120: ...4 56 Remote Operation TEC Event Enable TEEN i j Set query the TEC Controller Status Enable Register bit i to j TEEN 4 1 Example LDC500 Series Laser Diode Controllers...

Page 121: ...9 0 1 2 3 4 5 6 7 8 9 10 11 0 1 2 3 4 5 6 7 8 9 10 11 TECR TEPT TENT TEEV TEEN TEC Status CT CC T Stable Tuning IMAX IMIN VLIM T Fault TMAX TMIN TEC Open Runaway TEC ON 5 4 3 2 0 5 4 3 2 0 OPC Operat...

Page 122: ...is read only register represents the top of the status model and is populated with summary bit messages and interface condition bits Enabled bits within the Status Byte generate the IEEE 488 Request S...

Page 123: ...reading it always returns 0 This register is set and queried with the SRE command At power on this register is cleared 4 6 3 Standard event status ESR The Standard Event Status Register consists of 8...

Page 124: ...t source is on CC CP Set when the LD current source is in CP mode BW Set when the LD current source is in high bandwidth mode SCANNING Set when a multi point scan is in progress see SCAN LD STABLE Set...

Page 125: ...its in the LDCR These are Weight Bit Flag 1024 10 VTRIP 2048 11 OPEN 4096 12 TEC OFF 8192 13 TMAX 16384 14 TMIN 32768 15 TFAULT VTRIP Indicates the LD tripped o due to overvoltage OPEN Indicates the L...

Page 126: ...4 6 5 1 TEC controller positive negative transition TEPT TENT These two 16 bit wide registers control the mapping of transitions in the TECR to setting ags in the TEEV register For any particular even...

Page 127: ...it Flag 1024 10 TEC OPEN 2048 11 RUNAWAY TEC OPEN Indicates the TE tripped o due to open circuit OPEN Indicates the TE tripped due to thermal runaway 4 6 5 3 TEC controller status enable TESE This is...

Page 128: ...4 64 Remote Operation LDC500 Series Laser Diode Controllers...

Page 129: ...aser current 5 2 5 1 4 Transitions locked out 5 2 5 1 5 Responsivity 5 3 5 1 6 Photodiode current over ow 5 3 5 1 7 Responsivity under ow 5 3 5 1 8 Responsivity over ow 5 4 5 1 9 Trip o from TEC 5 4 5...

Page 130: ...e prohibited To allow live transitions from CC to CP mode either reduce the laser operating current or increase the PD Ilim value 5 1 3 Transitions with limited laser current 1 In CP mode if the laser...

Page 131: ...time a new photodiode power limit PWLM is set the instrument checks that the physical photodiode current limit still remains less than 5000 A 10 000 A for LDC502 Again if this occurs either the respo...

Page 132: ...ource if the TEC turns o for any reason 5 1 10 Trip off from temperature ABB E E ABB E ABB Any of these messages indicate the laser diode driver has tripped o because of a temperature limit setting No...

Page 133: ...ith the above message Verify the TEC wiring polarity and if reversed either correct the problem in hardware or with the TPOL command pagerefcmd TPOL A manual procedure to verify the TEC wiring polarit...

Page 134: ...thermal runaway 5 2 6 Polarity change locked out Turn off TEC to change polarity The TEC wiring polarity can be changed using the TPOL command page 4 39 However changes to the TEC polarity can only be...

Page 135: ...hutdown to occur in response to an ESD electrostatic discharge event If this occurs multiple times investigate whether there are signi cant ESD problems in the area where the LDC500 is operated If the...

Page 136: ...5 8 Error Messages LDC500 Series Laser Diode Controllers...

Page 137: ...cessories This chapter describes cables and accessories that are available for use with the LDC500 Series Laser Diode Controllers In This Chapter 6 1 Cables 6 2 6 1 1 Laser diode cables 6 2 6 1 2 TEC...

Page 138: ...ck PD Cathode PD Anode Shielding 6 ft 1 8m or 12 ft 3 6m Interlock Chassis GND LD Anode Sense LD Anode LD Cathode LD Cathode Sense 1 2 3 4 5 6 7 8 9 Interlock Chassis LD Vsense LD Cathode PD Cathode P...

Page 139: ...Brown Interlock Interlock PD Cathode PD Anode LD Anode Sense LD Anode LD Cathode LD Cathode Sense Green White Black Blue Red Red Red 1 6 7 8 9 2 3 4 5 Figure 6 2 Laser diode cable with ying leads SRS...

Page 140: ...ith the TEC output of the controller All SRS TEC cables are constructed for high exibility and high current capacity and optimized for use with the LDC500 Series Laser Diode Controllers The terminated...

Page 141: ...on of the cable see Figure 6 4 is available in one length 6 ft D sub 15 pin male to LDC500 501 502 1 2 3 4 5 7 8 10 12 14 15 TE TE Chassis Sensor 2W Sensor 2W TE Vsense TE Vsense Sensor 4W Sensor 4W 1...

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