LC-C50 Laser Controller User manual
Contents
1. signal warning pulses as short as 1 us may be generated To make these pulses visible the extension circuit elongates these signals to 0 3 s 2 2 Front panel The front panel of the LC C50 controller is shown in Fig 2 2 Several of the connectors and switches present were already briefly mentioned in the previous section Each of the panel items will now be discussed EMISSION AED Laser Controller LC C50 TRIGGERIN GATEIN MODULATE OUT Ee REMOTE VOLTAGE CONTROI O EO 8 O DISABLE EXTERNAL ON ENABLE ANALOG ANALOG DIGITAL DIGITAL DUTYCYCLE VSWR OVER FORWARD REFLECTED FORWARD REFLECTED LIMIT LIMIT TEMPERATURE POWER MAN GATE FREQUENCY MODE DUTY CYCLE OEZ 00006 0 0 Fig 2 2 Front panel of the LC C50 controller 2 2 1 Power switch The LC is switched on or off by the power switch The switch is illuminated if the controller is on When the switch does not illuminate if the unit is connected to the mains the fuse at the back of the LC is melted 2 2 2 Enable safety key switch The enable safety key controls the laser enabling If the key is in the disable position the laser cannot be enabled This is a safe situation If the key is in the enable position the laser can be enabled depending on the selected gating mode see section 3 2 2 2 3 Emission indicator The emission indicator is switched on if the laser is enabled The amount of laser power is depend2. 5V corresponds to 0 100 duty cycle In the RVC mode the display shows Rem Voltage Control 2 2 13 BNC Remote voltage in In the RVC mode the duty cycle is varied according to the external applied voltage to the REMOTE VOLTAGE INPUT as described in section 2 2 12 2 2 14 BNC Analog forward The ANALOG FORWARD output is a buffered output of the analog forward signal as described in Chapter Four of Ref 1 2 2 15 BNC Analog reflected The ANALOG REFLECTED output is a buffered output of the analog reflected signal as described in Chapter Four of Ref 1 2 2 15 BNC Digital forward The DIGITAL FORWARD output is a buffered output of the digital forward signal as described in Chapter Four of Ref 1 A warning LED is present above the BNC connector This LED is switched on if case of a failed condition 1 e digital forward signal is continuously 2 2 16 BNC Digital reflected The DIGITAL REFLECTED output is a buffered output of the digital reflected signal as described in Chapter Four of Ref 1 A warning LED is present above the BNC connector This LED is switched on if case of a failed condition i e digital reflected signal is becomes inactive 2 2 17 BNC Duty cycle limit The DUTY CYLCE LIMIT output is a buffered output of the duty cycle limit signal as described in Chapter Four of Ref 1 A warning LED is present above the BNC connector This LED is switched on if case of a failed condition 1 e duty c
3. LC C50 Laser Controller User manual Version 1 0 Firmware V1 0 Date 30 01 1999 Authors J Louwers M van Balen 1999 AED Electronics Bertelindislaan 3 5581 CS Waalre The Netherlands Acronyms DC Duty Cycle EEPROM Electrical Erasable Programmable Read Only Memory LC Laser Controller LCD Liquid Crystal Display LED Light Emitting Diode PWM Pulse Width Modulation RAM Random Access Memory ROM Read Only Memory RVC Remote Voltage Control uP Microprocessor Notice Always comply with the local law and regulations when using high power lasers AED Electronics guarantees operation of the LC C50 device as is without additional hardware AED Electronics dissociates itself from all claims when using the LC C50 Use of this device is at own responsibility Please study and follow the instructions in this manual 1 Introduction This manual describes the operation of the laser controller LC C50 The LC C50 is designed to control the operation of the Coherent DIAMOND G 50 100 Lasers Typical applications include laser cutting and engraving but also the scientific use is supported Some features of the LC C50 controller e Digital PWM circuit e Frequency and duty cycle are set through the controller s serial port or by potentiometers at the front panel e The laser output power at the selected frequency and duty cycle combination is displayed at the controller s liquid crystal display LCD The default calibration v
4. Remote voltage control Manual Manual Internal On External External Internal On Table 3 1 Overview of all LC C50 modes 3 1 3 Remote voltage control mode In the Remote Voltage Control RVC mode the laser controller generates a PWM signal with a variable duty cycle The duty cycle is determined from the voltage at the RVC IN input 0 5V corresponds to 0 100 duty cycle The frequency of the PWM signal is either read from the position of the frequency potentiometer power mode control switch in manual position LCD shows man Fig 3 3 top or a serial command power mode control switch in external position LCD shows ext Fig 3 3 bottom The remote voltage control mode is entered if the RVC switch is set to on and the modulation switch is in the internal position The selected frequency is shown on the LCD as is the text Remote Voltage Control The maximum modulation frequency is determined by the computational speed of the controller A practical value is 1000 Hz Flrlelgl LOON kHz main Rlem Wlojtialgle Colnit rjoll Flrlelgl LOON kHz lejxitD Rlem Volt algle Coinit rjoll Fig 3 3 LCD in Remote voltage control mode Top manual mode bottom external control mode 3 2 Gating As default the laser can be enabled by an active signal on the GATE IN input the manual gate switch or by a serial command in all modes see section 4 2 4 By seri
5. The setting of the controller is dependent on the position of the power mode control switch If this switch is in the manual mode the PWM signal is controlled by the position of the potentiometers LCD shows man Fig 3 1 top In the external mode the controller uses serial commands to set the PWM LCD shows ext Fig 3 1 bottom The standard mode is entered if the modulation switch is set to internal and the remote voltage control switch is in the off position The selected frequency duty cycle and laser power are shown on the LCD Firlelq LOON kHz main Duty 50 Wel 150 w Firlelq 100 kHz exit Diultiy 50 x 150 w Fig 3 1 LCD in Standard mode Top manual mode bottom external control mode 3 1 2 External modulation mode In the external modulation mode the PWM circuit of the laser is replaced by a user supplied PWM signal at the MODULATE IN input The external modulation mode is entered when the modulation switch is set to external The position of the power mode control and the remote voltage control switches is insignificant The LCD shows External modulation Fig 3 2 Elxitielrinjall Imloidju lialt ilo n Fig 3 2 LCD in External modulation mode Power Mode Switch Modulation Remote Voltage Switch Control Switch Standard Manual Manual Internal Off External External Internal Off External modulation X External X
6. al commands the laser can also be switched on and off 3 3 Initialization When the laser is switched on the laser controller initializes In this initialization the following actions take place 1 2 3 4 A The laser is disabled the PWM circuit is disabled The LCD is updated with an introduction screen If a user supplied calibration table is present in the E PROM it is copied to RAM Otherwise a default table is copied to RAM If the user has defined a custom waveform it is copied from E7PROM to RAM The gating mode is set to external gating The position of the three switches is read and the laser controller is set to the desired mode 4 Serial commands 4 1 Introduction The LC C50 laser controller can be configured via its serial port This configuration can take place by means of a simple terminal program or a user written program communicating with the computers serial port The default configuration of the controller s serial port is Baud Rate 9600 bits s Data bits 8 Parity N Stop bits 1 After each carriage return the LC C50 scans the input string After processing the input the LC C50 responds with the prompt LC C50 gt 4 2 Overview of commands 4 2 1 Help The LC responds with an overview of the available commands if is entered 4 2 2 LCD related commands The back light of the LCD can be toggled on or off by the commands led on and lcd off respectively 4 2 3 PWM relat
7. alues can be overruled by the user s calibration data To calibrate the laser a convenient calibration routine is present in the controller s firmware e Remote voltage control RVC mode allows modulation of the laser output by an externally applied voltage In the remote voltage control mode the laser is modulated at a fixed frequency by varying the duty cycle The duty cycle circuitry assures glitch free operation when the duty cycle is continuously varied A new value of the new duty cycle is only latched into the PWM circuit after each completed period e Modulation of laser by user defined waveforms e Light emitting diodes LED s at the front panel warn the user in case of a laser malfunction The outline of this manual is as follows Chapter 2 discusses the general operation of the laser controller and its front and back panels Basic operation of the laser controller is described in Chapter 3 The external serial programming of the laser controller is addressed in Chapter 4 2 Theory of operation In this Chapter the general operation of the Laser Controller LC will be discussed first Then the switches and connectors at the front and back panels are reviewed 2 1 General operation The main components of the laser controller are shown schematically in Fig 2 1 The controller is divided into two printed circuit boards the main board and the front panel printed circuit board The main board contains the core of the contr
8. and time References 1 OEM Manual DIAMOND G 50 100 Laser Coherent Laser Group 5100 Patrick Henry Drive Santa Clara CA 95054 USA Appendix A LC C50 specifications PWM Output Input signals Output signals Physical Properties Power Requirements Environment Frequency range Duty cycle range Trigger Gate External modulation Remote voltage control Modulate out Digital forward Digital reflected Duty cycle limit VSWR Temperature Analog forward Analog reflected Serial Interlock Size depth x height x width Mounting Single Phase Storage temperature range Operational temperature range Relative humidity 25 Hz 133 kHz 0 100 TTL input impedance 1 MQ TTL input impedance 1 MQ TTL input impedance 1 MQ 0 5 V input impedance 100 KQ TTL output impedance 1 KQ TTL output impedance 1 kQ TTL output impedance 1 kQ TTL output impedance 1 kQ TTL output impedance 1 KQ TTL output impedance 1 KQ 0 5V output impedance 1 KQ 0 5V output impedance 1 KQ RS 232 12V 12V signals 0 12V lt 50 mA 255 mm x 88 mm x 482 mm Standard 19 rack height 2E 100 170 VAc 170 240 VAc 200 mA 100 mA 10 C 60 C 0 C 40 C lt 95 Appendix B LC C50 default power calibration table The default calibration table for the LC C50 is given in Table B 1 This table is for the G50 mode If the controller is set to the G100 mode the contents of the calibration table are multipli
9. e laser to frequency for which it was not calibrated the output power is determined by a logarithmic interpolation between the closest frequencies Calibration can only be carried out in the standard external mode 4 3 Overview of serial commands Help overview of available commands lcd on LCD back light on default red off LCD back light off laser extgate Switch to external gating default laser intgate Switch to internal gating laser enable Enable laser default laser disable Disable laser freq lt frequency gt Set PWM frequency duty lt duty cycle gt Set duty cycle on trigger ramp up Ramp up on trigger on trigger ramp down Ramp down on trigger on trigger pulse Pulse on trigger on trigger sinus Generate sinus on trigger on trigger userwav Generates userwave on trigger trigger off Ends trigger mode userwave clear Clear waveform data stored in RAM userwave store Store waveform data from RAM to E7PROM userwave retriev Retrieve waveform data from E7PROM to RAM userwave show Show waveform data as stored in RAM userwave lt time gt lt duty gt Insert waveform datapoint at lt t ime gt with duty cycle lt duty gt settings factory Reset the controller to facotory settings laser lt type gt Select the lasertype G50 or G100 settings factory Resets laser to factory settings settings calibrate Starts laser calibration procedure version Shows firmware version and compilation date
10. ected by serial commands The LC starts sending the waveform to the laser when a low to high TTL transition is sensed at the TRIGGER input 2 2 9 BNC Gate in In the default mode the laser is only enabled when a high TTL signal is connected to the GATE IN connector In this way the laser can be switched on for a certain period by e g a pulse generator By serial commands it is possible to overrule the function of GATE IN and switch the laser on and off independent of the GATE IN signal see sections 4 2 4 and 4 2 5 2 2 10 Modulation switch The modulation switch allows the user to choose between the internal generated PWM signal or a user applied signal at the MODULATE IN input If an external source is selected the LCD display shows External Modulation 2 2 11 BNC Modulate in The MODULATE IN input may be connected to an external PWM signal generator TTL input This signal is used for laser modulation when the external modulation mode is selected see section 2 2 10 2 2 12 Remote voltage control switch The LC C50 controller is capable of modulating the laser power depending on an external applied voltage This mode is called Remote voltage control RVC and is selected by setting the RVC switch to ON During RVC mode the frequency is set by a serial command or by the frequency potentiometer depending on the selected power mode see section 2 2 7 The duty cycle is varied proportional to the RVC voltage 0
11. ed by a factor 1 72 in accordance with Ref 1 Intermediate values are determined by logarithmic extrapolation in duty cycle and frequency duty fregf 100 150 250 350 500 700 Ik 1k2 ik5 2k 3k 4k 5k 7k 10k 15k 20k 30k 40k 60k 100k _o foy0oy 0 0 0 os os os o ofolol o oj 0 0 0 0 o 10 38 20 55 30 62 40 65 50 f 20 31 45 53 61 62 64 64 64 64 64 64 64 64 63 64 64 65 65 66 67 60 20 32 46 56 66 67 69 69 69 69 70 70 70 7o 69 70 70 70 70 69 67 Table B 1 Default power calibration table for LC C50 duty cycle in frequency in Hz and power in Watt 20
12. ed commands In external controlled mode the frequency of the PWM can be set by the freq lt frequency gt command 100 Hz lt frequency lt 100 kHz The PWM clock signal is derived from a 40 MHz clock circuit by a digital divider This divisor n determines the PWM frequency according to _ 40MHz 100 n freq The divisor is n gt 4 The controller responds with the frequency set most closely to the requested frequency The duty cycle is set by the duty lt duty cycle gt 0 lt duty cycle lt 100 4 2 4 External Internal gating At power up the LC is set to external gating and the laser is enabled if an active signal is present at the GATE input or if the MANUAL GATE switch is pressed The gate can be overruled by the command laser intgate This situation corresponds to an active GATE input The gating can be re set to external gating by the command laser extgate By disabling the laser the output power is zero even if the LC has been set to internal gating next section 4 2 5 Enable Disable laser If the laser were set to internal gating it would continuously be enabled To be able to disable the laser the command laser disable can be used This command can also be used if the laser is set to the default external gating but the user wants to ignore the external gating signal and does not want to enable the laser To reset to the default enabled laser use the command laser enable Note that in all cases t
13. ent on the selected duty cycle and frequency 2 2 4 LCD The LCD display provides the user with information about the current settings the selected mode and current laser power The back light can be switched off with a serial command if the user wants to prevent the LCD light emission see section 4 2 2 2 2 5 Frequency potentiometer The frequency potentiometer allows the user to set the frequency of the PWM signal at 21 discrete values 100 150 250 300 500 700 Hz and 1 1 2 1 5 2 3 4 5 7 10 15 20 30 40 60 and 100 kHz Intermediate frequencies can be set by a serial command see section 4 2 3 The selected frequency is shown in the display 2 2 6 Duty cycle potentiometer The duty cycle potentiometer is used to set the desired duty cycle of the PWM signal from 0 to 60 in 1 steps The selected duty cycle is shown in the LCD display 2 2 7 Power mode selection switch The mode selection switch sets the desired power mode In the manual position the frequency and duty cycle settings are set as selected by the potentiometers In the external position the frequency and duty cycle settings are set via a serial command see section 4 2 3 In this mode the controller does not read the position of the two potentiometers So the power settings can not be changed accidentally in this mode 2 2 8 BNC Trigger in The LC C50 controller is capable of sending a user defined waveform to the laser This mode is sel
14. he interlock and safety key can still disable the laser 4 2 6 On trigger commands The LC C50 controller is capable of sending a series of PWM pulses to the laser according to a user programmed waveform This waveform is started when a low to high transition is sensed at the TRIGGER input The controller has to be set to the trigger mode This trigger mode is selected by the on trigger command which is then followed by a specification of the waveform to follow For convenience several waveforms are already present in the controllers memory see Fig 4 1 The user may also define a custom waveform The built in waveforms are ramp up and down pulse and sinus The time scale is in 1 ms units E g the commando on trigger ramp up 50 1000 generates a ramp up with a final duty cycle of 50 The total ramp time is 1000 ms viz 1 second The resolution is dependent on the length of the waveform to limit the maximum amount of memory required according to 0 lt t lt 10sec 1 msec 10 lt t lt 20 sec 2 msec 20 lt t lt 50 sec 5 msec 50 lt t lt 65 sec 10 msec After entering the on trigger command the LC generates a wave table Depending on the wave type this may take up to 10 seconds During this period the LCD shows Generating wave table The LC then waits for a positive flank on the trigger input The LCD shows On trigger During the waveform a bar graph is shown on the second line of the LCD This bar graph di
15. oller the microprocessor uP and its memory RAM ROM and E PROM The E PROM is used to store user data even if the controller is shut off like custom waveforms and calibration data The microprocessor communicates with the user through the front panel by means of switches potentiometers and a LCD RS 232 RAM ROM EPROM LCD Pulse extension Programmable PWM Laser Enable VO Interlock RS 485 Driver Safety Key 0000 OOO RS 485 Receiver Figure 2 1 Block diagram of the LC C50 laser controller The power output of the Coherent DIAMOND G 50 100 Laser is set by a Pulse Width Modulation PWM signal 1 The output power increases with increasing Duty Cycle DC of the PWM signal Varying the frequency of the PWM signal sets the properties of the laser beam The LC C50 controller contains a computer programmable PWM generator with variable frequency The laser can only be enabled when the enable safety key is in the enable position and the interlock switch is closed Several control signals are available to check the laser status These signals are generated by the laser as differential signals RS 485 RS 485 receivers at the front panel convert these signals to normal signals available at the front panel In case of an error situation light emitting diodes LED s light up at the front panel As several of these signals are only active during the high period of the PWM
16. ontroller by means of a terminal terminal program running on a personal computer or via a program communicating with the controller Any regular 3 wire serial cable can be connected to this connector 2 3 3 Interlock connector The interlock connector has several purposes e Safety interlock e g to be connected to the entrance door of the room where the laser is located e In serial connection with a user supplied water flow switch to prevent operation of the laser if no cooling water is flowing The interlock connector is a 3 pole DIN style connector with a screwlock A schematic of the interlock is shown in Fig 2 4 If the circuitry between poles 1 and 3 is not shortened the laser is not enabled Laser controller 12V ende sen hd Fig 2 4 Interlock circuitry of the LC C50 controller 2 3 4 Mains connector The main connector and the fuse are also found at the back of the controller This connector also accommodates the fuse 3 Basic operation This Chapter describes the basic operation of the laser controller The different modes are discussed 3 1 Overview of different modes By means of the switches on the front panel and the serial input the controller can be set to different modes In this section each of these modes is discussed Table 3 1 summarizes these different modes 3 1 1 Standard mode In the standard mode the PWM settings are controlled by the potentiometers at the front panel or by serial commands
17. splays the current duty cycle Each solid character represents 5 duty cycle After finishing a wave the LC can be triggered again by a positive edge on the trigger input The trigger mode is ended by the trigger off command Ramp Pulse Sinus 5 Up Down gt O gt gt 5 ES time Fig 4 1 Standard waveforms of the LC C50 controller The built in waveforms are available through the following commands on trigger ramp up lt duty gt lt time gt on trigger ramp down lt duty gt lt time gt on trigger pulse lt duty gt lt time gt on trigger sinus lt amp gt lt avg gt lt period gt lt time gt where lt dut y gt is the maximum duty cycle in lt time gt is the total time of the waveform in ms lt amp gt the duty cycle amplitude in lt avg gt the average duty cycle in and lt period gt the period of the sinus in ms If the user request a sinusoidal waveform the controller first generates a wavetable into its memory the message Generating wavetable is shown on the LCD Apart from the built in waveforms the user may also enter a custom waveform This waveform can be stored into the nonvolatile memory of the controller when the controller is shut off This stored waveform is used as the default waveform The waveform in the RAM memory can be cleared by the userwave clear command The stored waveform can be retrieved from the nonvolatile memory by the userwave retrie
18. ve command An entered waveform can be stored by the userwave store command Individual data points of the waveform are entered by the userwave lt time gt lt duty gt command where lt time gt is the time in ms and lt duty gt the duty cycle at that time The data points are automatically sorted when entered The waveform is linearly interpolated between the individual data points The userwave mode is entered by the on trigger userwave command After the last data point the controller shuts of the output signal and waits for another trigger at the trigger input So usually the last data point has zero duty cycle The maximum number of datapoints that can be entered is 100 The minimum number of datapoints for a userwave is 2 The userwave show shows a table of the entered waveform data Note that for all on trigger commands the laser has to be in external control mode The trigger mode can be disabled by switching to the internal control mode or by the trigger off command 4 2 7 Laser settings The settings factory resets the laser to it s factory settings e Laser type G50 e Calibration table according to the Appendix B e No user defined wave form The settings calibrate starts the calibration procedure of the laser The laser is set to sequence of different duty cycles and frequencies At each of the duty cycle frequency combination the user inputs the total laser power In case the user sets th
19. ycle limit signal becomes active 2 2 18 BNC VSWR limit The VSWR LIMIT output is a buffered output of the vswr limit signal as described in Chapter Four of Ref 1 A warning LED is present above the BNC connector This LED is switched on if case of a failed condition i e vswr limit signal becomes active 2 2 19 BNC Temperature The TEMPERATURE output is a buffered output of the over temperature signal as described in Chapter Four of Ref 1 A warning LED is present above the BNC connector This LED is switched on if case of a failed condition i e over temperature signal becomes inactive 2 2 20 Manual gate As of s n 98002 the LC C50 laser controller is equipped with a manual gate switch This allows manual gating of the laser Pressing the manual gate switch down gates the laser momentarily From this position the switch veers back to its central position laser off Lifting the switch gates the laser until the switch is switched back to its central position 2 3 Back panel Several connectors are present at the back of the controller see Fig 2 3 Fig 2 3 Back panel of the LC C50 controller 2 3 1 Laser output connector The DB 25 connector at the back of the controller is connected to the laser by a 1 1 Male Female ribbon cable For a description of the pins of this connector see Ref 1 2 3 2 RS 232 connector The DB 9 RS 232 connector at the back of the connector allows external programming of the c
Download Pdf Manuals
Related Search