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1. Waiting for button press Writing CITT TT TT Dont disconnect USB cable 5 Now wait till Firmware upgrade was successful message appears It will take up to 1 minute to complete Firmware upgrade complete xj J Firmware upgrade was successfull 6 Click OK in Firmware upgrade complete messagebox Firmware Upgrade window will close and Watt Pilot control window will start 8 3 FIRMWARE UPGRADE WAS UNSUCCESSFUL OR IN TERRUPTED In case firmware upgrade ended unsuccessfully due to some reasons cable disconnection program crash Usually such error will be thrown then trying to use Watt Pilot Figure 38 Error thrown if device firmware becomes corrupted In order to recover follow these steps 1 Close Watt Pilot software 2 Turn off controller using ON OFF switch 3 Press and hold down Firmware upgrade button located inside con troller box see Figure 37 on page 64 to find there it is 4 Turn on controller while holding firmware upgrade button pressed 5 Release button after 10 second after power on 6 Launch Watt Pilot software and try to use the device 7 Firmware will be correctly rewritten automatically Device will be ready to use after one minute Altechna 9 LIST OF TABLES Table 1 Controller specifications oo et eeeee eens 31 Table 2 STEP DIR INTERFACE connector pin out 35 Table 3 STEP DIR INTE
2. Altechna WATT PILOT MOTORIZED ATTENUATOR USER MANUAL Rev 3 November 2013 www altechna com Altechna WATT PILOT November 2013 Copyright UAB Altechna All Rights Reserved No part of this manual including the products and software described in it may be reproduced transmitted transcribed stored in a retrieval system or translated into any language in any form or by any means ex cept documentation kept by the purchaser for backup purpose without the express written permission of UAB Altechna hereinafter ALTECHNA Product warranty or service will not be extended if 1 The product is repaired modified or altered Unless such repair modi fication of alteration is authorized in writing by ALTECHNA OR 2 The serial number of the product is defaced or missing ALTECHNA PROVIDES THIS MANUAL AS IS WITHOUT WARRANTY OF ANY KIND EITHER EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO THE IMPLIED WARRANTIES OR CONDITIONS OF MERCHANTABILITY FOR A PARTICULAR PURPOSE IN NO EVENT SHALL ALTECHNA ITS DI RECTORS EMPLOYEES OR AGENTS BE LIABLE FOR ANY INDIRECT SPE CIAL INCIDENTAL OR COSEQUENTIAL DAMAGES INCLUDING DAMAGES FOR LOSS OF PROFITS LOSS OF BUSINESS LOSS OF USE OR DATA IN CONTENTS T GE UE IK mm maa a 3 141 Watt PHOT SAO AESEMDUOA tapan 3 1 2 General safety reguirements mmm 3 Poe MGG ee aal aa alajaamad aasal taa 3 18274 SE EEEE OAA E T
3. but with outdated firmware is used STEP DIR current value is used if motor enabled If ENABLE pin is high motor is completely disconnected This caused lack of holding torque on idle state and step position could be lost This was fixed for SATT controllers in firmware version v8 released on August 22 2012 and newer controllers STEP DIR current setting is abandoned in latest controllers Altechna 5 6 STEP DIR INTERFACE CONNECTOR PIN OUT AND SPECIFICATIONS STEP DIR INTERFACE connector is used to operate controller in Step Dir mode or use UART interface instead USB The type of connector is 15 pin D SUB female 2 1 Figure 19 STEP DIR INTERFACE 15 pin D SUB female connector on the controller case Table 2 STEP DIR INTERFACE connector pin out Pin No Name Type 1 Step A In Optocoupler anode 2 Dir A In Optocoupler anode 3 Enable A In Optocoupler anode 4 ZeroPosC Open Collector 5 ModeSel In Pulled up to 5 V 6 UartOn In Pulled up to 5 V UartRx In 8 Not Connected 9 Step K In Optocoupler cathode 10 Dir K In Optocoupler cathode 11 Enable K In Optocoupler cathode 12 ZeroPost Open Emitter 13 GND Controller ground 14 UartTx Out 13 5 V Power output Table 3 STEP DIR INTERFACE connector electrical specifications Input pins Description UartRx UART baud rate 38 400 8 data bits 1 stop bit no p
4. Enable input pin in STEP DIR INTERFACE connector Example ent off motor power is controlled by input pin Now send ss to save this setting to controller dir x This command is effective only in Step Dir mode Controls software disconnecting of Dir input pin switch SW F see Figure 18 Parameter x cw Dir pin is disconnected motor direction is clockwise ccw Dir pin is disconnected motor direction is counterclockwise off motor direction is controlled by signals on Dir input pin in DB 15 connector Example dir ccw set motor direction counterclockwise Now send ss to save this setting to controller Move motor by x steps Parameter x Integer number Can be positive motor turns clockwise and negative motor turns counterclockwise Place for negative notation x can be in range of 2 147 483 646 2 147483646 Example m 1000 to move 1000 steps clockwise and m 1000 to move 1000 steps counterclockwise gx Go to absolute coordinate Parameter x Integer number Can be positive and negative Place for negative notation x can be in range of 2 147 483 646 2 147 483 646 Example g 400 motor turns while internal step counter reaches 400 Then send m 1000 to move 1000 steps clockwise Now motor stands in 600 position ix Set coordinate counter to specific value Parameter x Integer
5. Started There are three devices attached to PC in shown screenshot Double click listed attenuator to open control window for it Columns description e Name It is useful to give meaningful titles for each Watt Pilot because they will be easily recognized if more than one is used in the same system For example name can be set to Harmonic WP and another attenuator can be named as 2nd Harmonic WP New name is saved into control ler internal memory so it will be visible even if connected to another computer Name length is restricted to 20 characters maximum Watt Pilot can be renamed from Watt Pilot control window Options gt Watt Pilot Name menu option e Serial Number This column shows unique Watt Pilot controller hardware serial num ber It is used to identify hardware at low level Use Options gt Watt Pilot Name menu option in control window to give meaningful name to attenuator e COM port Each Watt Pilot gets unique serial port name after first enumeration with computer This column shows USB serial port name assigned by Win dows COM port name is necessary to know for advanced users who want to use serial commands in their applications See chapter Serial commands and protocol on page46 for more details about this e Status This column shows Connected if attenuator control window is active otherwise it is blank File menu description Connect This opens
6. Use fixing screw to tighten both parts to gether Figure 3 Assembling the Watt Pilot Altechna 4 WATT PILOT SOFTWARE DESCRIPTION 4 1 COMPUTER REQUIREMENTS e Free USB port Watt Pilot is compatible with USB 1 1 USB 2 0 and USB 3 0 Computer administrator rights only for installation e Windows XP sp3 32 bit e Windows Server 2003 sp2 32 bit e Windows Vista sp1 32 64 bit e Windows Server 2008 32 64 bit e Windows 7 32 64 bit e Windows 8 32 64 bit e Microsoft Net framework 4 0 redistributable installs automatically 4 2 SOFTWARE INSTALLATION 1 Check for and download latest Watt Pilot software installer pack age from http www altechna com product details ohp id 824 2 Run downloaded Watt Pilot Setup exe installation file In case you are installing on operating system that does not meet reguirements only USB drivers will be installed Click Yes to continue IS Watt Pilot 7 0 1 0 Setup xi Windows XP Service Pack 3 or above is required to run Watt Pilot software Only serial port drivers will be installed so you will be able to control Watt Pilot by sending commands via serial port continue setup JE 3 Installation window will appear click Next to continue Watt Pilot 2 0 1 0 Setup Welcome to the Watt Pilot 2 0 10 setup Wizard This wizard will guide you through the installation of Watt Pilot 2 0 1 0 Itis recommended that you d
7. 5 05 4 52 1000 Enter required value 74 Ste program preferences mw 5 D e 2 5 Watt Pilot name and serial number is shown on each attenuator control window caption Watt Pilot can be renamed by Options gt Watt Pilot Name menu option Name is convenient if more than one device is used in the same system Name length can be up to 20 characters and is saved into controller memory Serial number is unigue for each Watt Pilot controller and cannot be changed as it is used to identify hardware at low level Please include serial number if contacting developers e Power meter panel always shows existing power after the attenuator Percentage range is from 0 to 100 of transmission Zero percent means that waveplate occurs at 45 degrees angle beam polarization is rotated by 90 degrees and is maximally attenuated Display reading 100 means that waveplate is rotated at minimum attenuation maxi 50 0 MW 5 05 mW Figure 9 Power meter panel Left Use absolute power measurement units checkbox is set in Options gt Preferences right checkbox is unset 50 0 If Use absolute power measurement units checkbox is set in Options gt Preferences or during calibrating numeric display showing mW be comes active Absolute power reading is converted from percentage value with respect to minimal and maximal measured power using pow
8. Illustration of Watt Pilotcontroller advanced features www altechna com 11 Altechna 5 2 CONTROLLER CONNECTIONS Watt Pilot front and rear connectors are shown in the pictures below Figure 16 Controller front view e USB connector is used to control Watt Pilot with computer e Firmware upgrade button is hidden under small hole highlighted by arrow Used to recover if firmware upgrade process crashed See TROU BLESHOOTING on page 65 necessary STEP DIR INTERFACE connector can be used to control Watt Pilot with microcontroller via UART or Sep Dir pulses See section Operation modes Step Dir mode on page 34 MOTOR Figure 17 Controller rear view Zero position switch or optical sensor USB connector 31 Step A 15600 aN 9 Step kK ModeSel 5 Internal 5V Internal GND 4 ZeroPosc rad 43415 JU Step Dir connector Internal Step Dir signal generation e Controller power supply socket Plug dimensions outer diameter 5 5 mm GND central pin diameter 2 1 mm 12 V Watt Pilot requires 12 VDC 2 A power supply ON OFF switch Green led indicatesthat controller is ON MOTOR connector 9 pin D SUB female Connect it to Watt Pilot atten uator See MOTOR connector pin out on page 40for more information Controller can be used to drive variety of bipolar stepper m
9. Int32 steps converts ratio 0 0 1 0 to waveplate angle in degrees ratio double in range 0 0 to 1 0 publicdouble GetAngleFromRatio double ratio double angle Math Acos Math Sgrt rati0 180 0 2 0 Math PI return angle Angular offset between waveplate and waveplate rotator is important so degrees parameter in GetStepPositionFromDegrees double de grees should be adjusted accordingly to offset before passing www altechna com 21 Altechna Altechna 7 WATT PILOT ATTENUATOR DIMENSIONS 7 2 BIG APERTURE ATTENUATOR DIMENSIONS 7 1 STANDARD ATTENUATOR DIMENSIONS 50 0 21 0 Li Figure 34 Mechanical drawings of Watt Pilot big aperture attenuator All dimensions shown in millimeters 7 3 WATT PILOT CONTROLLER DIMENSIONS 163mm Figure 32 Mechanical drawings of Watt Pilot standard attenuator continued All dimensions shown in millimeters Figure 35 Watt Pilot controller dimensions 22 www altechna com www altechna com 23 Altechna 8 TROUBLESHOOTING 8 1 REAL LASER POWER DOES NOT MATCH SHOWN IN SOFTWARE Click Home button inWatt Pilot Control window This eliminates an gular error which can occur if power is lost during waveplate motion 8 2 UPGRADE CONTROLLER FIRMWARE NOW MES SAGE APPEARS Sometimes Watt Pilot software will show dialog asking whether to up date firmware Upgr
10. Pilot control win dow Make sure that attenuator is correctly aligned before calibrating PS GATT101D calibration Step 1 Step 2 Select if you have Watt Pilot with waveplate CA gt 25 mm ep 3 highest power Go to Step 4 when such position is found e som am of a 1 0 wo gt Curent waveplate rotator position is 1800 steps 20 769 deg Stop Minimum measured value 000 mW Madmum measured value 1000 mw Figure 6 Calibration window Calibration procedure 1 Click GO button in section Step 1 and wait till motor stops This will drive waveplate holder to hardware zero limit switch This will allow ac curate homing from control window Homing is needed after power loss during motion and will eliminate any accumulated position error 2 Check checkbox in Step 2 if using Big aperture waveplate rotator See pictures below Standard rotator Step 2 checkbox must be unchecked Big aperture rotator Step 2 checkbox must be checked Figure 7 Standard and Big aperture waveplate rotators 3 Rotate waveplate by using buttons in section Step 37 and measure laser power after the attenuator Number on the buttons represents mo tor moving distance measured in stepper motor steps and rotation di rection One step equals to 0 0115 degrees for standard waveplate rota www altechna com 7 Altechna tor and 0 005 degrees fo
11. User manual for advanced users from supplier e Overwrite Dir Input option is used in Step Dir mode only If checked voltage level on Dir pins 2 and 10 in DB15 connector is ignored and motor direction is set depending on selection to the right Ask docu ment Watt Pilot User manual for advanced users from supplier e Motor current settings Setting motor current higher than default can cause permanent damage to motor or controller so current changing sliders are disabled by default In order to activate them please enter string understand without quotes in security text field Motion cur rent is used when motor rotates waveplate so it must be higher than Standby current Standby current is used when motor idles Additional STEP DIR current slider is present for controllers with serial numbers beginning with 4ATT or newer controllers with outdated firmware ver sion This current drives motor continuously when controller operates in Step Dir mode and motor is enabled by Enable signal on DB15 connector or by enable overwrite command Motor current is cut off completely if enable signal is lost In analogy with this Motion and Standby current values are used for controllers with serial number SATT or 6ATT so third slider is hidden Third slider should be used only by advanced users and does not relate to watt pilot attenuator directly Default motion current is 0 95 A for
12. control window for selected Watt Pilot it does the same as double clicking in device list If only one device is connected during pro gram startup control window will be opened automatically See chap ter Watt Pilot Control window on page 22 for information e Search For Devices This will force searching for Watt Pilot devices attached to computer It can help if not all devices are detected and listed automatically Close This will close Watt Pilot Selector window but leaves control windows opened if any Exit This will close Watt Pilot Selector window and all control windows too Help menu description e User Manual This will open this help file Altechna e About This will show software version and contact information Please include software version and controller serial number when contacting manu facturer 4 5 CALIBRATION In order to correctly change output power software needs to know at what angle A 2 waveplate is It can be fixed in any angle with respect to rotator It is known that waveplate is positioned at 45 degrees at highest attenuation point and 0 degrees at zero attenuation The purpose of calibration is to obtain angular offset between A 2 waveplate and rotator hardware zero position when one of these two conditions is met Cali bration window is opened automatically on first use of Watt Pilot or can be found in menu Options gt Calibration in Watt
13. is not 20 symbols then returned name can consist of unreadable characters Please space pad trailing name n Show name Returns 20 character string saved by sn command Return 20 character string 6 5 SOFTWARE RECOMMENDATIONS There are plenty of applications built for serial port communication Windows XP and full installations of Windows 7 or Windows 8 has na tive hypertrm exe terminal application which can be launched by typ ing hepertrm in Run dialog Winkey R Linux and OS X users can use free CuteCom http cutecom sourceforge net utility see Figure 28 on page46 For Windows OS it is recommended to use free tool terminal exe from https sites google com site terminalbppFigure 29 p 55 Configure terminal exe as follows 1 Select correct com port number see Identifying serial port name on page 44 2 Select correct serial port configuration values see Table 6 on page 44 3 Set Hex checkbox if received characters should also be shown as hexadecimal values 4 Click Connect button 5 Type in command and press Enter key on keyboard Command string p r is sent to device as shown in example picture Look at Se rial commands and protocol on page46 for available commands 6 Watt Pilot response is shown in middle pane Hex representation of all received bytes is shown on the right Controller speed setting is set to 550
14. ms and decode response If 1 parameter become 0 it means that motor has stopped and is ready for next move command zr X Report zero position when hitting zero position switch Parameter x 1 Controller sends string zp integer_value on each zero position button press 0 Turn off zero position reporting ZS X Reset coordinate counter then hitting hardware zero position switch Parameter x 1 Position counter will become 0 on each zero position switch press 0 Position counter increases position continuously en x Motor enable in Command mode Parameter x 1 Motor is enabled Motor is disconnected j Reset controller Controller resets in 4 s after issuing this command It is equivalent to power switch press This command can also enter into firmware upgrade mode if firmware upgrade button is pressed All changed settings and position are restored in previous state if ss and or so commands was not issued before reset Then controller starts it sends string STEP DIR mode or USB mode according to state of pin ModeSel a0 Turn off acceleration do Turn off deceleration 20 www altechna com SS Save settings of controller Save configuration mentioned in pc command description to controller memory Configuration saved by 1 ss command will be restored on controller power on SN X Write 20 character long name to controller Parameter x 20 characters If x
15. only via USB connection It will not work if RS232 level shifter is used ATTENTION UART pins are connected directly to controller s microprocessor which is 5 V device RS232 to 5 V UART converter must be used to connect de vice to PC for example MAX232 chip can be used for this e UartRx UartTx 5 V UART input and output pins see UartOn pin description These pins are not optically isolated If galvanic isola tion is needed special integrated circuits can be used for example ADUM1201 e GND Ground pin of controller internal circuit it is reference for Mode Sel UartOn UartRx and UartTx pins e 5V Internal controller 5 V Can be used for external circuitry and can supply up to 25 mA of current www altechna com 15 Altechna 5 7 MOTOR CONNECTOR PIN OUT MOTOR connector is used to connect bipolar stepper motor and home limit switch to controller The type of connector is 9 pin D SUB female Figure 23 Controller MOTOR connector Table 4 MOTOR connector pin out Description Controller serial number begins with Pin No 4ATT see SATT see BATT see Figure 22 p 39 Figure 22 p 39 Figure 21 p 38 1 Motor winding B output usually red wire Motor winding B output usually blue wire 3 Motor winding A output usually green wire 4 Motor winding A output usually black wire 3 No connection Zero position 6 Zero
16. position switch return CMOS input with pullup to 5 V 5V power sup No connection GND PE pai sensor up to 70 MA 8 No connection P A not used 9 Zero position switch GND Connector pin out changes were made in controller hardware revisions Only mechanical limit switch can be used with controller serial numbers 4ATT and 1 connected to pins 6 and 9 Latest Watt Pilots with GATT serial number come with optical home position sensor on ro tator so limit switch input circuit is essentially different from previous hardware versions See Figure 21and Figure 22 on page 38for differenc es 6AT T rotators are not compatible with 4ATT or 5ATT versions of controllers All versions of rotators can be used with 6ATT controllers Pull Up for zero position 5600 J 88 May be timerdriven Output o input gt gt n Q AT So ow t g 42 Output turn on ES Output turn on 63 Step Dir mode if needed O Inputs Outputs 5 8 SUPPORTED STEPPER MOTORS There are two types of stepper motors unipolar and bipolar Controller supports bipolar stepper motors In order touse unipolar motor as bipo lar center wires from both windings must be left unconnected Motor winding resistance multiplied by motor current must be less than 11 5 V Controller can drive up to 2 A maximum currentand 1 6 A contin uous ST281851006
17. stepper motor can be chosen as reference for motor requirements because it is used as waveplate rotator Unipolar stepper motor Bipolar stepper motor Motor wire Controller pin number A Black A 4 Com Leave Com Yellow i Yellow unconnected A Green i A 3 EN aie 8 1 a E Com Leave lt oO o White unconnected E BN 2 Figure 24 Using unipolar motor as bipolar Table 5 Stepper motor ST281851006 electrical characteristics Winding voltage 2 66 V Winding Current 0 95 A Winding Resistance 280 Resistance of motor windings usually is less than 10 Ohms so wires to the motor must be as short as possible and with significant wire diame ter gt 0 75 MM2 or lt 20 AWG to minimize wiring impact to motor noise 5 9 WATT PILOT CONTROLLER CONNECTION EXAMPLES AND INPUT CIRCUIT DIAGRAM Connect pins 5 and 13 to activate Step Dir mode Controller internal st ModeSel S circuitry 5V digital wn 8 ee Inputs outputs 3 3 Karaat a IE dr 12 EZTA ectronics Output 2 Dir ETOM A m t ee Input 1 Zero pos ZeroPosc Ta E Figure 25 Connecting external eguipment to use Watt Pilot controller in Step Dir mode Weak pull ups Internal circuitry Watt Pilot controller Figure 26 Connecting Watt Pilot controller to microcontrolle
18. v2 46 6 Watt Pilot software requires Microsoft NET Framework 4 Client Profile or higher version to be installed Setup will offer to download it choose Yes if you have active internet connection Choose No to download it from http www microsoft com en us download de tails aspx id 17113 and install it manually You should choose No if you wish to install any newer version of framework or do not have a working internet connection This dialog will not appear if framework is already installed Download size is 42 Mbytes IF Watt Pilot 2 0 1 0 Setup P Watt Pilot requires Microsoft Met framework 4 Client profile or higher to be installed Do you want to 9 download and install Microsoft Net framework v4 0 Client profile download size is 42 MB res I 7 Setup will download Microsoft NET Framework 4 Client Profile PS Watt Pilot 2 0 1 0 Setup Please wait while Watt Pilot 2 0 1 0 is being installed Downloading dotNET4 exe 2246kB 59 of 419928 at 745 7kB s 53 seconds remaining Ea Nullsoft Install System v2 46 Back www altechna com 5 Altechna 8 After download is finished Microsoft NET Framework 4 Client Pro file will be installed wait for it to complete This can take more than 10 minutes on slower machine E Microsoft NET Framework 4 Client Profile Setup Installation Progress SW Please wait while the WET Fram
19. 00 as seen in example screenshot Presets can be configured for frequently used commands Click Set Macros button Macro Settings window will appear Macro Settings Load Save oe Transmit Macros s0 D Step 1000 a m2 m2 7000 E Figure 30 Command string presets can be configured by clicking Set Macros button in main terminal exe window Type in string which should be sent and name of this preset Hexadeci mal values can be entered with prefix For example command end symbol r 0xOD should be entered as SOD Stop command defini tion is shown in example Click Save button to save your presets Stop button will appear in Macros pane of main window Press it to stop attenuator motor motion bi by Broy 3 Terminal 1 9b AA BeScan am Help About COMs Setting Set font AutoBis Connect Time Stream log O AutoStart Script 8 JF Stay on Top 14400 E at 19200 56000 Receive CLEAR Autoscroll Reset Crit E Ent 53 Transm CLEA Send File OP CR CR LF BREAK 2 RTS USC te ae an ea A STS TES Set Macros Stop Ma 4 M5 ME Mi Ma Mg 10 M11 M12 M13 M14 M15 M16 M1 M18 M19 M20 427 M22 123 HESI Disconnected Rx 68 T 2 Re OF E custom BA
20. 8 Block diagram of Watt Pilot controller 12 www altechna com 5 4 OPERATION MODES COMMAND MODE This is thefirstof two possible controller operation modes Command mode is selected if pin5 ModeSel is left unconnected in front STEP DIR INTERFACE connector Motor position is set by sending ASCII commands to controller Con troller has USB and UART interfaces for communication STEP DIR ENABLE inputs are disconnected in this mode Watt Pilot appears as virtual serial port in computer device list when connected Watt Pilot software uses this port to change attenuation It is easy to write own program to integrate with controller Device can be accessed by any serial port program USB drivers are available for Windows Windows CE Mac or Linux see List of supported operating systems for USB drivers on page 44 Serial commands are listed in Serial commands and pro tocol on 80646 Apart from USB UART connection is available in STEP DIR INTERFACE connector It can be used to communicate with microcontroller or pro long cable length with RS232 level shifter See STEP DIR INTERFACE connector pin out and specifications on page35 ATTENTION Watt Pilot software only supports Command mode and only via USB connection It will not work if RS232 level shifter is used ATTENTION UART pins are connected directly to controller s microprocessor whic
21. Ax Clear ASCII table Scripting CTS 0 5600 j Graph Remote 1058 n L All Bin ASCII StartLag Stoplog Reg Resp N ml kati PUSB 1 a 232 d 2432 s 55000 wm lld ws 36 mt lld en l Altechna top 51 E E RTS CT5 ON 40FF ATSACTS 40N460FF ATS onT invert 3 53 Figure 29 terminal exe window with p command sent 6 6 SERIAL COMMAND USAGE WITH NATIONAL INSTRU MENTS LABVIEW There is a Serial port control in LabView Add it to your LabView project and set its properties to parameters listed in Table 6 page 44 Then use commands described in Serial commands and protocol p 46 to control motor use g xx m xx commands for moving and com mand for checking if motor has stopped To calculate motor step posi tion for required laser power use formulas shown in in chapter Relation between motor position and laser power on page56 6 7 RELATION BETWEEN MOTOR POSITION AND LASER POWER Transmitted laser power ratio can be in range of 0 0 max attenuation to 1 0 min attenuation According to Malus law waveplate angle pcan be calculated from ratio p cos ratio degrees In order toget motor step position steps from waveplate rotator angle userelation steps p k r where coefficient k is steps per unit depending on wave
22. LUDING THE PRODUCTS AND SOFT WARE DESCRIBED IN IT THIS MANUAL IS DIRECTLY CONNECTED TO FIRMWARE VERSION LATEST FIRMWARE SOFTWARE AND MANUAL VERSIONS CAN BE DOWNLOA DED FROM www altechna com Products and corporate names appearing in this manual may or may not be registered trademarks or copyrights of their respective com panies and are used only for identification or explanation and to the owner s benefit without intent to infringe 5 4 Operation modes Command 100 13 5 5 Operation modes Step Dir mode mm 13 5 6 STEP DIR INTERFACE connector pin out and specifications 13 S7 MOTOR COMMECION PIN OU raa tei ahta tem a 16 5 8 Supported Stepper MOtofs mmm 16 5 9 Watt Pilot controller connection examples and input circuit diagram 16 6 WRITING SOFTWARE FOR WATT PILOT 17 6 1 List of supported operating systems for USB drivers 17 572 89 1112 151910186 1 16 1 11 29989955678 2958289989 77 17 6 3 Identifying serial port NaMe 17 6 4 Serial commands and protocol 17 6 5 Software recommendations 444444 20 6 6 Serial command usage with National Instruments LabView 21 6 7 Relation between motor position and laser power 21 7 WATT PILOT ATTENUATOR DIMENSIONS 22 74 Standard attenuator dimensio
23. NTROLLER HARDWARE 5 1 CONTROLLER SPECIFICATIONS Watt pilot controller isbipolar stepper motor driver with specifications listed in Table 1 below Table 1 Controller specifications Characteristic Rating Max output voltage 12V Max output current 2A Current regulation type Pulse Width Modulation Microstepping capability Full Half Quarter Eight Sixteen steps Step frequency Up to 4 kHz Open loop operation no external position feedback encoder Position feedback Controller protection Driver have overheating and over current 2A protection Device can be operated by Step Dir pulses e Computer software via USB port e Microcontroller via UART connection One limit switch can be connected and used only for homing Limit switch Advanced feature is STEP DIR INTERFACE connector which enable controller to be used with custom electronics not only computer based applications SV TTL A Microcontroller with UART port or Step Dir signal generator can be connected to D SUB15 connector in a Computer with USB port Watt Pilot software or self written software can control attenuator or motor Interface logic signal generation order to control motor A J Bipolar stepper Waveplate rotator or 2V 2A power supply motor driver other bipolar stepper motor can be driven position switch signal Figure 15
24. Preferences Usually this should be executed every time when device is turned on File menu description e Save Calibration Current program settings can be saved to file Configuration file includes all options in Options gt Preferences preset values and calibration off set Run time program configuration files are saved in folder Application data for all users Altechna Watt Pilot Settings Load Calibration Program settings can be restored from file Configuration file includes all options in Options gt Preferences preset values and calibration offset Current configuration will be overwritten Altechna e Show Device Selector This will open Watt Pilot Selector window Close This Window This will disconnect from Watt Pilot and close active Contro i window Options menu description e Calibration This will open Watt Pilot calibration window See chapter Calibration on page 20 for details e Preferences This will open program configuration window See chapter Program preferences description on page 26 for details e Watt Pilot Name This will open Rename Device window Use up to 20 characters for name Enter new name and click OK to accept Rename Device o Enter new Watt Pilot name a A M Figure 11 Rename Device window Motor Settings submenudescription e Set Safe Settings This optio
25. RFACE connector electrical specifications 36 Table 4 MOTOR connector pin out 41 Table 5 Stepper motor ST281851006 electrical characteristics 42 Table 6 Serial port parameters mmmmm ena 44 Table 7 Serial commands list 47 www altechna com 25 Altechna Altechna NOTES 26 www altechna com www altechna com 27 Altechna www altechna com WATT PILOT MOTORIZED ATTENUATOR USER MANUAL Rev 3 November 2013 UAB Altechna Mokslininky st 6A 08412 Vilnius Lithuania Tel 370 5 2725738 Fax 3 0 5 2723704 E mail info altechna com
26. S input with absolute maximum voltage rating 5 5 V I User 5V 1f 9 1 260 User zero position signal Rotatorisin Notin zero zero position position Pin 4 Voltage STEP DIR INTERFACE connector D SUB15 Female Altechna MOTOR connector D SUB 9 Female Watt Pilot controller G f Optical sensor i i i sensor output Normally 5V OV in zero position i i i I l Figure 21 Zero position input circuit diagram for controllers with serial numbers starting with 6ATT Only mechanical limit switch can be attached to 4ATT or 5ATT con trollers because input circuit is different from 6ATT controllers it is shown in the picture below i 1 User 5V i STEP DIR INTERFACE 9 User zero position signal Switch released Switch pressed Internal 5 connector D SUB15 Female MOTOR connector D SUB9 Female Watt Pilot controller gt Zero position switch pin 7 connected to GND in SATT controllers i i 1 Wot connected in 4 1 i Figure 22 Zero position input circuit diagram for controllers with serial numbers starting with 4ATT and SATT WARNING 6AT T controllers support every Watt Pilot attenuator but 6ATT attenu ator cannot be driven by 4ATT or SATT controller Because of mechanical zer
27. T 3 1 5 Operating and storage conditions mmmmm 2 2 OPERATION PRINCIPLE 4 3 PACKAGING CONTENTS 4 3 1 Wat pilot man Companen erosa ara a 4 02 9006 2511 Gaeli EEA E kka 4 4 WATT PILOT SOFTWARE DESCRIPTION pisi jutita 5 A KOMPU SI reg ire METIS kraana tati miine e 5 4 2 Software installation mmmmmmma J 4 3 Programi E TUN eros pahvndtoce inetd rE EEEE EEEE RRE 6 4 4 Watt Pilot Selector window mmm 6 A lll AN s sist aa t E 7 46 Wat Pilot Conto WIRGOW geresniais kekik a i 8 4 7 Program preferences description 10 4 5 Motor settings descripto matkata prikk kaia 10 4 9 Firmware update 11 5 WATT PILOT CONTROLLER HARDWARE 11 Sd Controller SOCCINCATION Sy lepe ala 11 9722 Controller Connect ONS eee o ear e AE 12 5 3 Controller internal block diagram 12 2 www altechna com TERUPTION OF BUSINES AND THE LIKE EVEN IF ALTECHNA HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES ARISING FROM ANY DEFECT OR ERROR IN THIS MANUAL OR PRODUCT SPECIFICATIONS AND INFORMATION CONTAINED IN THIS MANUAL ARE FURNISHED FOR INFORMATIONAL USE ONLY AND ARE SUBJECT TO CHANGE AT ANY TIME WITHOUT NOTICE AND SHOULD NOT BE CON STRUED AS A COMMITMENT BY ALTECHNA ALTECHNA ASSUMES NO RESPONSIBILITY OR LIABILITY FOR ANY ERRORS OR INACCURACIES THAT MAY APPEAR IN THIS MANUAL INC
28. ade controller firmware now Controllers you are trying to connect SATT233D firmware is not up to date v3 Do you want to upload latest firmware v13 mow Figure 36 Dialog asking whether to update firmware This will appear if controller firmware cannot be updated without user interaction and depends only on controller firmware version not related to hardware revision It will pop up if controller has firmware version prior to v8 released on August 22 2012 These dialogs will newer show up againonce firmware is updated WARNING Upgrade process cannot be interrupted Do not disconnect USB atten uator or power supply cables do not shutdown the computer Do not use other devices while flashing If upgrade is interrupted or unsuccess ful go to the end of this troubleshooter point to recover Follow these steps to update firmware manually 1 Answer Yes when asked about update dialog is shown in Figure 36 Firmware Upgrade window will appear Click Upgrade Firmware but TOM iix Rescan serial ports coma 5ATT233D In order to update controller s firmware follow these instructions 1 Click Upgrade Firmware button below 2 Press and hold Firmware upgrade button on Watt Pilot controller box until this text dissappears Manually choose hex file for advanced users only Firmware file 7 hex Browse for hex file 24 www altechna com 2 Progress b
29. ar on lower part of the window begins to fill now program is waiting for user to press Firmware upgrade button which is located inside controller box Proceed to next step Firmware Upgrade 658 serial ports COM4 SATT233D Connecting waiting for user button press LP and hold Fi y i har 2 Hold that button pressed until instructed to release by next message al Manually choose hex file for advanced users 0887 Firmware file hex Browse for hex file Dont disconnect USE cable 3 Press and hold firmware upgrade button located under small hole on controller s front panel This must be done in one minute otherwise process must berestarted Firmware upgrade button is marked by yel low arrow in the picture below It can be accessed with teeth stick for example Figure 37 Firmware upgrade button location inside Watt Pilot controller 4 Hold Firmware upgrade button pressed until confirmation about re lease will be displayed in Firmware Upgrade window as shown below Usually button must be held pressed up to 15 seconds Process status is displayed above progress bar Firmware Upgrade l lol x Rescan serial ports COM4 SATT233D Please release Firmware upgrade button on controller box Writing AFirmware SATT v13hex _ E Manually choose hex file for advanced users only Firmware file Browse tor hex file
30. arity UartTx RXD and TXD pins are 5 V compatible with reference to GND pin Maximum input voltage is 5 5 V Step Dir En These pins are optically isolated 3 3 V 5 V compatible Input current requirement per pin 46 MA 28V 5 2 MA 3 3V 6 8 5 V ModeSel These logic pins are 5V compatible with reference to UartOn GND pin Maximum input voltage is 5 5 V Below is the description of STEP DIR INTERFACE pins e Step A Step K 3 3 V 5 V compatible input to optocouplers anode Step A and cathode Step K Rising edge on Step A pin with reference to Step K advances motor by 1 step in Step Dir mode Motion direc tion depends on Dir signal level All stepper motors suffer from resonance Watt Pilot rotator tends to resonate at frequencies from 100 to 300 Hz so such low STEP frequen cies should be avoided in Step Dir mode Vibration can be eliminated by setting higher micro stepping in settings www altechna com 13 Altechna It is necessary to mention that motor shaft is inert Frequency of STEP signal should be controlled linearly especially at high motor speeds Motor should accelerate and decelerate smoothly For instance control logic must sweep down STEP freguency before changing DIR level Simi larly frequency must be swept up then reaching high motor speed Step Dir mode signal timing requirements are shown in Figure 20 ModeSel lg Motor d
31. c command instead Altechna 2 Boolean 1 or 0 Motor enable motor is enabled if 1 and motor is disconnected if 0 This setting is meaningful if parameter 1 is On 3 Boolean 1 or 0 Status of switch SW F see Figure 18 1 means that Dir pin is disconnected and motor turns clockwise if 4 parameter is 1 or counterclockwise if 4 is equal to 0 If 3 is 0 then motor direction is dependent on logic level on Dir input 4 Boolean 1 or 0 Motor direction motor turns clockwise if 4 parameter is 1 or counterclockwise if 4 is equal to 0 This setting is meaningful if parameter 3 is On 5 Reserved 6 Reserved 7 Reserved Response example default controller settings swEn 0 en 1 swDir 0 dir 1 zr 0 zs 0 cs 0 This command can be used to ping controller to check pc if controller is attached to particular COM port If device response to p r string begins with pUSB it means that Watt Pilot is attached and is turned on Return string finished with 0x0A and OxOD symbols USB 1 a 2 d 3 s 4 wm 5 ws 6 wt 7 r 8 en 9 zr 10 zs 1 1 1 Boolean 1 or 0 Current operating mode Command mode if 1 and Step Dir mode if 0 2 Integer 0 255 Acceleration value 3 Integer 0 255 Deceleration value 4 Integer 1 65500 Speed value 5 Integer 0 255 Motor motion current value 6 Integer 0 255 Motor idle current value 7 Integer 0 255 Moto
32. celeration and 255 is the highest 0 turns off deceleration Turning on deceleration helps to increase position repeatability Show controller settings related to Step Dir mode Type this command only when using terminal and manual command entering This is the way to see settings in eye friendly fashion To get controller settings for software programming use pc command instead Return string finished with 0x0A and 0x0D symbols swEn 1 en 2 swDir 3 dir 4 zr 5 zs 6 cs 7 All returned parameters are boolean 0 or 1 1 Boolean 1 or 0 Status of switch SW E see Figure 18 1 means that Enable pin is disconnected and motor is enabled if 2 parameter is 1 or disabled if 2 is equal to 0 If 1 is O then controller output state is dependent on logic level on Enable input Show all controller settings separated by semicolon Use this command when programming computer software to read all settings Return string finished with 0x0A and 0x0D symbols 1112113111411511611 18 911110111 1111121111 3 114111 51 1611 118111 9 1120 21112211231 241 Character meaning 1 Boolean 1 or 0 Current operating mode Command mode if 1 and Step Dir mode if 0 2 Integer 0 1 2 or 3 Current motor run state 0 motor is stopped 1 accelerating 2 decelerating 3 running at constant speed 3 Integer from 0 to 255 Acceleration value 4 Integer from 0
33. chna 18 Boolean 1 or 0 Motor enablesetting in Step Dir mode motor is enabled if 1 and motor is disconnected if 0 This setting is meaningful if parameter 1 is On 19 Reserved 20 Boolean 1 or 0 Status of switch SW F see Figure 14 means that Dir pin is disconnected and motor turns clockwise if 17 parameter is 1 or counterclockwise if 17 is equal to 0 If 20 is 0 then motor direction is dependent on logic level on input 21 Boolean 1 or 0 Status of switch SW E see Figure 14 1 means that Enable pin is disconnected and motor is enabled if 18 parameter is 1 or disabled if 18 is equal to 0 If 21 is 0 then controller output state is dependent on logic level on Enable input 22 Reserved 23 Reserved 24 Reserved Response example default controller settings 1 0 232 232 55000 1 14 36 1 14 2 1 1 0 0 0 1 0 1 1 1 0 0 0 0 1 Return running state of the motor and current position Return string finished with 0x0A and 0x0D symbols 11112 1 Integer 0 2 or 3 Current motor run state 0 motor is stopped 1 accelerating 2 decelerating 3 running at constant speed 2 Integer in range of 2147483646 2147483646 Current motor position Response example 3 4437 Use this command to determine if motor has done its movement After issuing any move command poll o command in time intervals about 250
34. e slider Automatically execute GO after required power change must be checked for this options to be enabled Use absolute power measurement units Setting this will enable power to be measured with absolute measurement units Minimum and maxi mum power values must be known for this option to work This setting can also be changed in Calibration window e Measurement units to use Alohanumerical string can be entered here to represent measurement units Default is mW but can be changed to UW if working with micro watts e Minimal and Maximal power meter reading These fields must be filled with minimal and maximal measured power values Decimal separator symbol is dot X These values will appear as available power range in main window e Use absolute measurement units for preset buttons If this is set pre set button values are shown as absolute power values otherwise pre set button values mean of transmitted power Option Use absolute power measurement units must be set for this option to be enabled Preset button values are recalculated automatically with respect to min and max measured power 10 www altechna com 4 8 MOTOR SETTINGS DESCRIPTION Motor settings can be accessed from Watt Pilot Control window by Options gt Motor Settings gt Advanced These settings are for ad vanced users only Security passphrase for motor current controls is understand P
35. ed range Measurement units are available because absolute minimal and maximal power values are set in program preferences during calibration process 8 www altechna com places can be used Valid range is 0 00 100 00 Option Automati cally execute GO after required power change must be selected in Op tions gt Preferences if waveplate should rotate automatically after value of this field is changed Otherwise click GO button to actually set power e Absolute required power field is available if Use absolute power meas urement units option is set in Options gt Preferences or Options gt Calibration Decimal point symbol is dot Valid range is from Mini mum measured value to Maximum measured value set in program preferences Option Automatically execute GO after required power change must be selected in Options gt Preferences if waveplate should rotate automatically after value of this field is changed Otherwise click GO button to actually set power e Preset buttons can be used to quickly set predefined output power Left click on any of them and appropriate value will appear in 4 or 5 text boxes If Option Automatically execute GO after required power change is selected in Options gt Preferences waveplate will rotate au tomatically otherwise click GO button to actually set power In order to edit preset valu
36. ed using 6 plastic bolts 3 for each polarizer Adapter for polarizer s and waveplate mount are fixed while using M4 screw Adapter for polarizer s can vary from showed in picture depending from polarizer s type Brewster or Broadband thin film polarizer and opera 4 www altechna com tional mode reflection or transmission mode Also big aperture attenu ator option is available Watt Pilot can be fixed to an optical table using posts and clamps or to the custom system while using M6 or M4 screw on the bottom and M4 screw on the side Seechapter WATT PILOT ATTENUATOR DIMENSIONS on page 58 3 2 OPTICS ASSEMBLING Powder free gloves must be worn while mounting optical components Avoid touching or scratching optical surfaces STEP 1 Place polarizers into mechanical adapter Polarizers must face each other with surfaces coated with dielectric coating Dielectric coat ing is marked with an arrow so you have to put the polarizer s with the arrows on the sides facing each other Then fix polarizer s with the plastic bolts use all 3 plastic bolts to fix one polarizer Do not tighten up the bolts too much since it can bend the polarizer and thus distort the laser beam STEP 2 Put the wave plate into attenuator between two mounting rings as shown Be sure that wave plate is immobilized tightly STEP 3 Attenuator con sists of two mechanical parts User should as semble both mechani cal parts together STEP 4
37. ements on pagel 2 serial port name could be checked in Windows Computer manager Right click on My Computer 1 se lect Manage 2 Computer manager window will appear Click on Device Manager under Computer Management tree 3 and look for Ports COM and LPT 4 Each connected and powered on attenuator appears as Silicon Labs CP210x USB to UART Bridge Serial port name Serial port name is shown in parentheses as seen in the picture below iF Plets COM amp LPT Sticon Labs CP 210 USB to UART Bridge COM32 2 Siicon Labs CP210x USB to UART Bridge COM39 E Processors f m L eee ee 1 1 Figure 27 Finding Watt Pilot serial port name using Windows Computer Manager 111 Third way to identify Watt Pilot is to open each serial port and send p command If attenuator is present on that port it will send back string starting with USB as listed in Serial Commands and protocol on page 46 If device is not present no bytes will be received or received string will not begin with USB Serial port read timeout can be set to 50ms to Speed up scanning process This method is universal and can be used with any operating system Read next chapters about serial port param eters and command list Linux users can find Watt Pilot port by executing command root dmesg grep cp210x root Aivaras home Aivaras installpk
38. er meter Correct min and max power values must be set in pro gram preferences or calibration windows e Lower slider changes power from 0 to 100 in 0 25 steps Values in lower numeric fields will alter according to slider position There is a triangle shaped marker above lower slider which shows power cur rently set in real time the same as power meter panel displays Both options Automatically execute GO after must be selected in Op tions gt Preferences if power should be set immediately after slider move Otherwise click GO button to actually set power e Enter required value field is used to manually enter percentage of Watt Pilot transmission Decimal point symbol is dot two decimal gt 2 Power meter panel Shows output power value at which attenuator is currently set to No 4 Enter required power level here in percent Click GO to set 5 Absolute required power field is used to set 6 Preset buttons instantly change required power power level using known units if correctly set in 8 Immediately stops Watt Pilot rotation 9 Hold this button to constantly decrease power power 9 Hold this button to constantly increase 7 Click GO to apply power level which is shown in text boxes Figure 8 Watt Pilot Control window Currently laser power is set to 5 05 mW or 50 of full calibrat
39. es right click on any preset button Edit Preset Buttons window will appear Edit Preset Buttons x All numeric values below must be in the range 0 100 5 Button 1 Button 2 Button 3 Button 4 Button 5 0 25 50 75 100 ok Figure 10 Edit Preset Buttons window Currently preset values are 0 25 50 75 100 of transmission because checkbox is unchecked Otherwise all values would represent absolute power in user selected units Option Use absolute measurement units for preset buttons will be ena bled only if measurement units are correctly configured in Options gt Preferences If checkbox is set clicking on preset button will update Absolute required power field 5 else Enter required value field 4 will be updated with value displayed on button e GO button Click to set power rotate waveplate STOP button will cancel rotation e Buttons lt lt and gt gt will continuously decrease increase power Con troller firmware must be up to date for these buttons to appear These buttons are not available for controllers with serial numbers beginning with 4ATT If Rotate continuous option in program preferences is set waveplate can be rotated to any angle otherwise waveplate motion is restricted to 0 45 degrees Home button will drive waveplate rotator to home limit switch and back to Home position set in Options gt
40. ework is being installed Microsoft File security verification All files were verified successfully Installation progress i Installing MET Framework 4 Client Profile Gancel 9 Setup will finish by installing drivers Click Next to continue Es Watt Pilot 2 0 1 0 Setup Installation Complete Setup was completed successfully 59 Completed EEE Output folder C Program FilesVAltechnaWatt Pilot Creating schortouts Create folder C Documents and Settings All Users Start Menu Programs Altechna Create folder C Documents and Settings All Users Application Data Altechna Watt Create shortcut C Documents and Settings All Users Start Menu Programs Altechn Create shortcut C Documents and Settings All Users Start Menu Programs Altechn Create shortcut C Documents and Settings Users Desktop Watt Pilot Ink Output folder C Program Files Altechna Watt Pilot Create shortcut C Documents and Settings All Users Start Menu Programs Altechn Create shortcut C Documents and Settings All Users Start Menu Programs Altechn Created uninstaller C Program Files Altechna Watt Pilot uninst exe Completed Mullsort Install System v2 46 Gancel 10 Click Finish to end installation Program cannot be opened if only drivers were installed see step 2 for details FS Watt Pilot 2 0 1 0 Setup Completing the Watt Pilot 20 1 0 Setup Wizard Wat
41. g Downloads cutecom 0 22 0 1486 las txz Verifying package cutecom 0 22 0 1486 las txz Installing package cutecom 0 22 0 1486 las txz PACKAGE DESCRIPTION CuteCom A graphical serial terminal like minicom H It 1s aimed mainly at hardware developers or other people who need a terminal to talk to their devices It is free software and distributed under Lhe GNU General Public License Versioun 2 which can find in Lhe file COPYING Cutecom is heavily inspired by Bray for Windows P ackage cutecom 0 22 0 1486 las txz installed rooteAivaras home Aivaras cutecom No protocol specified cutecom cannot connect to X server 0 root Aivaras home Aivaras dmesg grep cp210x 515 118805 USB Serial support registered for cp210x 515 118847 cp210x 5 1 1 0 cp210x converter detected 515 355645 usb 5 1 cp210x converter now attached to ttyUSBO 515 355685 usbcore registered new interface driver cp210x 515 355691 cp210x vO 09 Silicon Labs CP210x 85232 serial adaptor driver 1196 500459 cp210x ttyUSBG cp210x converter now disconnected from ttyUsBa 1196 500493 cp210x 5 1 1 0 device disconnected 1202 112687 cp210x 5 1 1 0 cp210x converter detected 1202 349780 usb 5 1 cp21Gx converter now attached to ttyUSBC root Alvaras home Aivaras L Figure 28 Finding Watt Pilot serial port under Linux Screenshot is taken on Slackware Linux 13 37 32 bit OS In the picture above we can see that one Wa
42. gt Connect Program will up date controller firmware if necessary Usually this process is automatic and does not require any action just wait until Firmware upgrade was successfull message appears If problems arise with firmware update see Firmware update on page 30 and TROUBLESHOOTING on page 62 Once connected to Watt Pilot dialog will popup informing that no cali bration file is found for new attenuator Initial startup i 24 Settings file not found Please calibrate waveplate offset before using attenuator Do you want to calibrate it now Figure 4 Dialog box shown if Watt Pilot calibration file is not found Select Yes calibration window will appear Use instructions in section Calibration on page20 to setup calibration After calibration is done Watt Pilot control window will appear Use slider to select and set required power See section Watt Pilot Control window window on page22if more information is needed 4 4 WATT PILOT SELECTOR WINDOW Watt Pilot Selector window contains a list of currently connected and powered attenuators This window is used to choose device to work with if there are several controllers connected to single computer Func tions of this window are described in the picture below File Help and Watt Pilot 6ATT155D ard Waitt Pilot SATT233D Figure 5 Watt Pilot Selector window It is displayed every time program is
43. h is 5 V device RS232 to 5 V UART converter must be used to connect de vice to PC for example MAX232 chip can be used for this 5 5 OPERATION MODES STEP DIR MODE This is the second of two possible controller operation modes Step Dir mode is selected by connectingpin 5 ModeSel to pins 13 GND in STEP DIR INTERFACE connector USB connection and computer are not necessary in this mode Motor ro tates according toelectric signals applied to STEP DIR INTERFACE con nector These signals are called STEP pins 1 9 DIR pins 2 10 and ENABLE pins 3 11 DIR signal sets rotation direction of the motor 0 V motor rotates counterclockwise 5V motor turns clockwise Volt age transitions from 0 V to 5 V on STEP input advances motor per one step 5 Von ENABLE pin will reduce motor current to Standby current value set in settings and STEP signal is ignored Otherwise Motion cur rent flows to motor and STEP pulses rotate the motor Use ENABLE input to reduce motor heating More details can be found in STEP DIR INTERFACE connector pin out and specifications on page 35 ATTENTION Motor current is set by ENABLE signal so leaving it high can overheat the motor so proper ENABLE handling must be implemented by wir ing or by using commands ATTENTION In case controller with serial number 4ATT or controller 5ATT
44. isabled High En Motor current stand by current USB mode selected High STEP DIR mode selected Low Motor enabled Low Motion current Step 8725 t Motor direction clockwise High r D i r Counter clockwise Low Symbol Description Min Typ Max Unit ModeSel wait time Controller switches to Step Dir mode tA l 1 S after ModeSel pin goes low tB Wait time for first valid STEP pulse after En pin goes low 20 ms C Time A motor current reaches motion current 15 18 20 a value after En pin goes low D Time ER motor current reaches stand by current 15 18 20 value after En pin goes high tE STEP pulse period 35 15 tF STEP high level time 5 US tG STEP low level time 10 US tH DIR setup time 5 US tl DIR hold time 7 US Figure 20 Step Dir mode input signal timing requirements e Dir A Dir K 3 3 V 5 V compatible input to optocoupler anode Dir A and cathode Dir K This input controls motor direction in Step Dir mode 5 V on Dir A pin with reference to Dir K sets motor direction clockwise This input can be overridden by command parser see Se rial commands and protocol on page 46 and Figure 18 SW F on page 33 for details e Enable A Enable K 3 3 V 5 V compatible input to optocoupler an ode Enable A and cathode Enable K This input reduces motor current in in Step Dir
45. istur bance values according to IEC 61326 1 1 5 OPERATING AND STORAGE CONDITIONS For proper Watt Pilot functioning please use assigned controller found in the same package Using unassigned controller might be harmful to the device Environmental conditions that must be hold while storing servicing and operating are e Storage temperature should be between 25 C and 60 C Operating temperature is 25 C 10 C Watt Pilot must be protected from humidity dust and corrosive va pors to avoid damaging optical components and electronics e Avoid strong static electricity and electromagnetic fields www altechna com 3 Altechna 2 OPERATION PRINCIPLE The motorized Watt Pilot incorporates 2 high performanceBrewster type thin film polarizer s which reflect s polarized light while transmit ting p polarized light Rotating phase retardation of A 2 wave plate is placed in the incident polarized laser beam The intensity ratio of those two beams may be continuously varied without alteration of other beam parameters by rotating the waveplate The intensity of either exit beam or their intensity ratio can be controlled over wide dynamic Brewster type thin film polarizers Rotating waveplate Incident laser beam range P polarization should be selected for maximum transmission or high purity s polarization should be reflected when maximum attenu ation of the transmitted beam takes place Proper f
46. lot The customer is solely responsible for laser safety while using Watt Pilot as standalone device or integrated into system The customer must con sider protective measures While assembling or operating Watt Pilot do not stare at the direct or scattered laser light even with safety goggles All parts of the body must be kept away from the laser radiation While adjusting laser beam through Watt Pilot laser power must be kept as low as possible Ha zardous laser radiation can increase while optical components or instru ments are used in combination with Watt Pilot Appropriate eye protec tion must be worn at all times Electrical safety requirements must be complied while assembling and operating Watt Pilot 1 3 SYMBOLS WARNING Sections marked with this symbol explain dangerous situations that can result as personal injury or death Always read the associated informa tion carefully before performing indicated procedure ATTENTION Paragraphs preceded by this symbol explain hazards that could damage the instrument and connected equipment or may cause loss of data This manual also contains NOTES and HINTS written in this form 1 4 REGULATION ATTENTION The following statement applies to the products covered in this manual unless otherwise specified herein The statement for other products will appear in the accompanying documentation Altechna These limits are designed to provide reasonable protec
47. mode 5 V on Enable A pin with reference to Enable K reduce motor current to Standby current value set in controller set tings Otherwise Motion current flows to motor and STEP pulses ro tate the motor This input can be overridden by command parser see Serial commands and protocol on page 46 and Figure 18 SW F on page 33 for details ATTENTION Motor current is set by ENABLE signal so leaving it high can overheat 14 www altechna com the motor so proper ENABLE handling must be implemented by wir ing or by using commands ATTENTION In case controller with serial number 4ATT or controller 5ATT but with outdated firmware is used STEP DIR current value is used if motor enabled If ENABLE pin is high motor is completely disconnected This caused lack of holding torque on idle state and step position could be lost This was fixed for SATT controllers in firmware version v8 released on August 22 2012 and newer controllers STEP DIR current setting is abandoned in latest controllers e ZeroPosC ZeroPosE These pins are used to sense zero position switch state Phototransistor is open low resistance state if pin 7 in MOTOR connector is 0 V and closed high resistance if pin 7 is 5V logic high 6AT T controllers come with attenuator which optical sensor out put is normally high and if rotator is in zero position Pin 7 is CMO
48. n will set waveplate rotator angular velocity to 8 73 deg s with acceleration and deceleration on Such motor settings should be used if Optimized settings causes motor to stall or miss steps Such problems may arise with old worn out attenuators Attenuation from 0 to 100 is changed in 7 seconds These timings apply to Standard small ap erture waveplate rotator e Set Optimized Settings This will set waveplate rotator angular velocity to 14 076 deg s no ac celeration and no deceleration This is more faster motion than Safe settings Attenuation from 0 to 100 is changed in 3 19 seconds Waveplate turns 360 degrees in 25 6 seconds These timings apply to Standard small aperture waveplate rotator All new attenuators will perfectly work with such option selected e Advanced This will open Motor settings window where motor speed can be tweaked It can be used for trouble shooting or to find optimal working point between optimal and safe Help menu description e User Manual Show this help file e About This will show software version and contact information Please include software version and controller serial number when contacting manu facturer www altechna com 9 Altechna 4 7 PROGRAM PREFERENCES DESCRIPTION Preferences window can be accessed by Options gt Preferences menu item in Watt Pilot control window GATTLOID preferences Rota
49. ns 22 72 BIg aperture atentator dinen ON S 1 10 tatamil tan 23 7 3 Watt Pilot controller dimensions 23 2 TROUBLESHOOTING ts taala TE 24 8 1 Real laser power does not match shown in software 24 8 2 Upgrade controller firmware now message appears 24 8 3 Firmware upgrade was unsuccessful or interrupted 25 9 LIST OF TABLES 5030 cons nrei reiese 25 MT mammu 39 26 1 INTRODUCTION This user manual is designed to help to install and operate Watt Pilot Be fore installing and operating Watt Pilot please read installation and ope ration instructions carefully Safety instructions must be read carefully If there are any guestions about contents of this manual please contact info altechna com ALTECHNA reserves the right to update contents of this manual without any notification 1 1 WATT PILOT SHORT DESCRIPTION Motorized Watt Pilot is a computer controlled laser beam attenuation device It attenuates free space laser beam pulse continuously without introducing additional energy fluctuations Watt Pilot is controlled by computer via USB Also it has STEP DIR INTERFACE connector for con trolling via other devices 1 2 GENERAL SAFETY REOUIREMENTS Motorized Watt Pilot is designed to operate in conjunction with laser system All applicable rules and regulations for safe operation of lasers must be known and applied while installing and operating Watt Pi
50. ntered in relevant fields of Step For example one uses 1 W laser and 20 mW is measured as minimal power and 0 99 W as maximal power So it is handy to check Use ab solute power measurement units put value 0 02 into field Minimum measured value 0 99 into Maximum measured value and write W into Enter measurement units to use textbox because measurement units are Watts 7 Click OK button to accept calibration or Cancel to discard If dialog asking to home will appear answer Yes for correct device operation 4 6 WATT PILOT CONTROL WINDOW This window is used to change laser power after Watt Pilotattenuator Calibration procedure must be finished before correct attenuator opera tion Main components of this window are described below 1 Watt Pilot name and serial number A Output power level is always shown as percentage because itis directly related to waveplate angle Power also can be shown with absolute measure ment units if correctly set in program preferences P Ist Watt Pilot 6ATT1010 Upper indicator represents actual power level E GE OOP ae J 3 Move lower slider to change reguired power level Click GO button to apply it A 10 This will drive waveplate to Home position set by calibration process and preferences 0 10 3 00
51. number Can be positive and negative Place for negative notation x can be in range of 2 147 483 646 42 147 483 646 18 www altechna com Example SX 625 set coordinate to 625 Now send so to save position to controller Resets coordinate counter to 0 st Stop motor smoothly if it is currently running This is preferred command to stop motor instead of b Bake movement immediately This command stops motor but step counter accuracy can degrade using watt pilot Zp Go to hardware zero position and reset step counter Set maximal motor speed Parameter x Integer number in range of from 1 to 65000 Watt Pilot waveplate rotation angular speed can be calculated using such formula 14400000 W 7 78 65535 x Here w angular waveplate rotation speed degrees per second r micro stepping resolution 1 2 4 8 or 16 Controller advances motor per one step in time intervals equal to T 65535 x 8 us Use this command to return waveplate to its home p position determined by zero position switch Then motor stops controller stores in coordinate counter and saves this value rx Set motor micro stepping resolution Parameter x 1 Motor is driven in full steps mode Waveplate holder turns once in 15600 steps for standard attenuator or 36000 for big aperture 2 Half step mode Waveplate holder turns once in 31200 steps 4 Ouarter s
52. o position switch zero position optocoupler signal should be debounced or used only first voltage spike detected for accurate zero position detection e ModeSel Then this pin is connected to GND pin 13 controller switch es into Step Dir mode If this pin is left unconnected or applied 5 V with reference to controllers ground pin 13 Step Dir Enable inputs be come disconnected and controller works in Command mode Mode Sel pin controls internal switches SW B SW C SW D Controller internal block diagram on page 33 ModeSel pin is not optically isolated and is pulled up to internal 5 V See Watt Pilot controller connection exam ples and input circuit diagram on page 42 e UartOn This pin controls internal switch SW A which sets command path to the command parser Controller internal block diagram on page 33 Then this pin is connected to GND pin 13 controller isac cessed by 5V UART interface UartRx and UartTx pins instead of USB port Useful if controller is operated by user s microcontroller FPGA All Command mode commands are valid If this pin is left unconnected or applied 5 V with reference to GND command parser gets commands via USB port UartOn pin is not optically isolated and is pulled up to in ternal See Watt Pilot controller connection examples and input circuit diagram on page 42 ATTENTION Watt Pilot software only supports Command mode and
53. ose all other applications before starting Setup This will make it possible to update relevant system files without having to reboot your computer Click Mext to continue 4 Click Next Es Watt Pilot 2 0 1 0 Setup Program Version History 5 Program changes from previous versions can be seen here Updated user manual WATT PILOT Manual September 2013 pdf Updated firmware v3 Added numeric power meter display in main window Added menus in main and selector windows Added calibration settings backup and restore support Added Status collumn in Watt Pilot Selector list Added option to automatically execute GO command after required power change Added Home button in main window Added email message generation for quick feedback Click on scrollbar arrows or press Page Down to review the entire text MullsoFt Install System v2 46 lt Bak net gt 5 Select installation directory and click Next to begin installation Watt Pilot 2 0 1 0 Setup M jol Choose Install Location Choose the folder in which to install Watt Pilot 2 0 1 0 K Setup will install Watt Pilot 2 0 1 0 in the following folder To install in a different folder dick Browse and select another folder Click Install to start the installation C Program Files Altechna Watt Pilot Space required 10 0MB Space available 19 358 Nullsott Install System
54. otors not onlyWatt Pilot attenuator For example most linear stages are driven by stepper motors so these controllers can be used to control them See Supported Stepper Motors on page41 about such capability 5 3 CONTROLLER INTERNAL BLOCK DIAGRAM Watt Pilot controller consists of three blocks Each is shown in Figure 18 e Motor driver This block drives motor by controlling currents in motor windings according to Step Dir Enable and motor power signals e Command parser This block parses commands acquired from USB or UART depending on switch A state SWA The state of switch A can be changed by logic level on input UartOn in STEP DIR INTERFACE con nector Also this block can select which Enable and Dir signals to use in Step Dir mode internally generated or picked up from STEP DIR IN TERFACE connector pins Switch E and F are used for this purpose e Internal Step Dir signal generator This block generates acceleration continuous speed and deceleration step pulses Also DIR and enable signals when controller is working in Command mode Set motor Command power Motor Feedback from zero position switch parser driver my e a lu ES E gt lt E Bz 2 o m2 TT a DP u 2 SAJA A z i x w es 2 gt 5 7 5 5 r 2 Q w w pe Figure 1
55. plate rotator k 43 333 steps deg for standard attenuator and k 100 0 for big aperture attenuator coefficient r is controller sresolution parameter it must be read from controller using p command or got in Watt Pilot software Options gt Motor Settings gt Advanced r can be 1 2 default 4 8 16 microsteps per step So motor step position steps using standard attenuator with default unchanged from purchase set tings can be calculated as steps cos vratio 43 333 2 where ratio is required transmission 0 0 1 0 43 333 is step per de gree for standard attenuatorand 2 is default resolution multiplier Usually arccosine function acos found in programming packages op erates with radians so degrees must be converted to radians Real rela tion between ratio and steps used in Watt Pilot software is calculated using following C methods Returns step position to be passed to g steps command ratio double in range 0 0 to 1 0 publiclnt32 GetStepPositionFromRatio double ratio return GetStepPositionFromDegrees GetAngleFromRatio ratio j stepsPerUnit 43 333 for standard attenuator or 100 0d for Big aperture attenuator resolution 1 0d 2 0d 4 0d 8 0d 16 0d depending on controller settings publiclnt32 GetStepPositionFromDegrees double degrees double steps degrees stepsPerUnit resolution return
56. r big aperture attenuator using default settings It is advisable to search for lowest power max attenuation position be cause usually it can be spotted more easily and accurately Power meter is not necessary for relative coarse power attenuation min power can be found using visualizer 4 Select appropriate option in Step 4 when minimum or maximum power is found Angular offset is recalculated and shown in Step 7 fleld every time Step 4 selection is clicked At this moment main calibration goal is completed and Apply button can be clicked to apply changes Further steps are optional but can be set for convenience 5 Calibration result can be verified using buttons in Step 5 panel Us age example click Drive to minimum power button and wait till rotator stops Use buttons 10 and 10 located in Step 2 to ensure if current position is really of lowest power If it is click Apply else select Mini mum power in Step 4 again to redefine offset The same can be done with maximum power point Checking both min and max positions in Step 5 makes no sense 6 Non ideality of polarizers and waveplate will cause losses so 100 percent transmission will pass less energy than available and 0 trans mission actually does not block all radiation Real maximal and minimal transmitted power can be measured while calibrating Watt Pilot in Step 5 These extreme values should be e
57. r current value in Step Dir mode 8 Integer 1 2 4 8 or 6 Micro stepping resolution value full half guarter eight or sixteen 9 Boolean 1 or 0 Motor enable motor is enabled if 1 and motor is disconnected if 0 10 Boolean 1 or 0 Whether to report coordinate then hitting zero position switch if 1 or do not report if 0 If this option is on 1 controller sends string zp integer_position on each zero position button press 11 Boolean 1 or 0 Whether to reset position counter on each zero position switch press or no If this option is disabled 0 zero position button press does nothing to step counter If waveplate holder turned twice command o will show us that position is more than 15600 15600 is full waveplate turn in full stepping mode If this position is enabled 1 position counter will become 0 on each zero position switch press Response example default controller settings USB 1 a 232 d 232 s 55000 wm 114 ws 36 wt 114 r 2 en 1 zr 0 25 0 Integer number in range of from Oto 255 Motor current pt can be calculated using such equation 0 00835x A a X Set acceleration Parameter x Integer number in range of from O0 to 255 1 is the lowest acceleration and 255 is the highest O turns off acceleration Turning on acceleration helps to increase position repeatability Set deceleration Parameter x Integer number in range of from to 255 1 is the lowest de
58. r employing all of Watt pilot features 16 www altechna com Altechna 6 WRITING SOFTWARE FOR WATT PILOT 6 1 LIST OF SUPPORTED OPERATING SYSTEMS FOR USB DRIVERS In order to communicate with Watt Pilot USB drivers are necessary These are available for more operating systems than Watt Pilot soft ware Virtual USB Com port drivers can be installed on Windows 2000 32 bit Windows XP 32 bit Windows Server 2003 32 bit Windows Vista 32 64 bit Windows Server 2008 32 64 bit Windows 7 32 64 bit and Windows 8 32 64 bit There is no need to install any drivers on modern Unix like Linux MAC operating systems Watt Pilot is automatically recognized and installed as ttyUSB device after connecting it to computer You can check which serial port is assigned in your UNIX machine with command root Idmesg grep cp210x 6 2 SERIAL PORT PARAMETERS Serial port parameters to be used are shown in a table below Table 6 Serial port parameters Baud rate 38400 Parity None Handshaking None Stop bits 1 6 3 IDENTIFYING SERIAL PORT NAME First step to control Watt Pilot using serial port and commands would be to find out which serial port is assigned for device This can be seen in Watt Pilot Selector window list see section Watt Pilot Selector win dow on page18 In case only drivers were installed no Watt Pilot software itself see Computer reguir
59. rally type com mands in terminal window These symbols are not visible but they format received data window text so it looks organized www altechna com 17 Altechna From computers perspective each command is ended by byte r Enter key press usually sends this symbol in most of terminal programs Com mand and command parameter is separated by space symbol 0x20 For example typing such string g 3000 in terminal application and pressing enter key on the keyboard will drive waveplate rotator to abso lute position of 3000 steps Here g 0x67 is a command space 0x20 is a separator and 3000 0x33 0x30 0x30 0x30 is a command param eter which corresponds to 3000 steps All sent bytes in hexadecimal will be 0x67 0x20 0x33 0x30 0x30 0x30 OxOD including command end symbol wr or Enter key press New command can be sent after 50 ms There is no command acknowledge in protocol so 50 ms delays be tween commands must be inserted Otherwise command misinterpre tation can occur See table below for command list Table 7 Serial commands list Command Description ent x This command is effective only in Step Dir mode Controls software disconnecting of Enable input pin switch SW E see Figure 18 Parameter x 1 Enable pin is disconnected motor is enabled Enable pin is disconnected motor is disabled off motor power is controlled by signals on
60. s Motor settings for 6ATT101D Motor Current Enter security passphrase found in user manual section Motor settings Motion Current 0 95 A Resolution Step Frequency 1224 21 122 1 5211 7Hz FP Accelerate FP Decelerate Step Dir Settings Overwrite Enable Input Enabled z FP Overwrite Dir Input CockWise Standby Current 0 30 A Ps Motor settings for SATT233D section Motor settings oes Motion Current 0 95 A Resolution 1 2 Half Steps 0 0115 956 5159 Step Freguency 7594 122 1 5211 7Hz M Decelerate Standby Current 0 30 A IV Accelerate STEP DIR Current 0 95 A b Figure 13 Motor settings window a Controller with latest firmware and serial number beginning with SATT or 6ATT Optimized settings are applied Controller with outdated firmware or serial number beginning 4ATT applied Safe settings Passphrase understand is entered in security field so motor current can be adjusted e Motor Enabled checkbox If unchecked no current flows through the motor windings Default is checked e Resolution Stepper motor can be driven in microstepping mode so one motor step can be physically divided into 1 no microstepping 2 half microstepping 4 8 or 16 microsteps That means that standard waveplate rotator can have resolution of 15600 31200 62400 124800 or 2496000 steps per full turn Big aper
61. standard and big aperture attenua tors standby current is 0 3 A by default e Write settings button Click this button to save configuration into con troller memory Currently displayed settings will be reloaded after con troller power cycle If this button is not used previously saved changes will be loaded after controller restart e Read settings button This will load configuration from controller Altechna 4 9 FIRMWARE UPDATE Once connected Watt Pilot software checks firmware version on device and updates it if necessary Progress bar will popup informing user that firmware update is in progress and one must wait until flashing process is finished Firmware Upgrade Connecting Writing AEHAAEAA Dont disconnect USB cable Firmware upgrade complete Figure 14 Normal firmware update process finish is indicated by Firmware upgrade complete message ltwill take up to one minute and requires that user do not disturb up date process This process is not cancellable Do not disconnect USB or power supply cables do not shutdown the computer This window can appear after Watt Pilot software is updated because latest firmware comes with Watt Pilot installer file Confirmation message will appear after update is completed click OK and program will continue as usual If firmware upgrade window is different than shown here see TROU BLESHOOTING chapter on page 62 5 WATT PILOT CO
62. t Pilot 2 0 1 0 has been installed on your computer Click Finish to dose this wizard F Run Watt Pilot 2 0 1 0 al 6 www altechna com 11 Watt Pilot software icon will appear on All Users desktop and All Users start menu 12 Connect waveplate rotator to Watt Pilot controller 13 Connect Watt Pilot and PC via USB cable 14 Plug in Watt Pilot power supply jack and AC adaptor to wall outlet 15 Windows will detect new hardware Wait until windows configures new device J Found New Hardware x Your new hardware is installed and ready to use JJ Found New Hardware x CP2102 USB to UART Bridge Controller 16 Device installation is now complete launch Watt Pilot program using Watt Pilot icon on desktop 4 3 PROGRAM FIRST RUN Launch Watt Pilot program using Watt Pilot icon on desktop or from Start Menu gt All Programs gt Altechna gt Watt Pilot gt Watt Pilot Watt Pi lot Selector window will appear At least one device must be displayed in the list If the list is empty please check USB cable power connection and ON OFF switch it must be in ON position Green LED near pow er switch must be active if power is OK Click File gt Search For Devices to refresh For more information about Watt Pilot Selector window see section Watt Pilot Selector window on page 18 Select Watt Pilot from a list and click File
63. te continuous Home position ANAN eN EEE 7 M Automatically execute GO after required power change lv Automatically execute GO after slider change Use absolute power Measurement units Measurement units to use roy Minimum measured value 0 10 Maximum measured value 10 00 Use absolute measurement units for preset buttons Cancel OF Figure 12 Program preferences window Can be found under menu Options gt Preferences Rotate continuous If checked waveplate can be rotated continuously using lt lt or gt gt buttons in control window This will cause attenuation to change from min to max 8 times in 360 degrees turn This option can be useful to check if current waveplate calibration is set for best contrast ratio possible For example best contrast can be get if using second or third 45 degree slot For this option to appear controller firmware must be updated to latest This option is not available for controllers with se rial numbers beginning with 4ATT Home position Power can be set to max or min power after Home button clicked e Automatically execute GO after required power change This allows waveplate to rotate automatically if required power was changed by editing values in numeric fields e Automatically execute GO after slider change This allows waveplate to rotate automatically if reguired power was changed by moving th
64. tep mode Waveplate holder turns once in 62400 steps 8 Eight step mode Waveplate holder turns once in 124800 steps 6 Sixteen step mode Waveplate holder turns once in 249600 steps Higher micro stepping levels demonstrate better position accuracy and no motor resonance It is advisable to use half stepping operation mode WS X Set motor current then it is idles This removes motor heat Some amount of current must be left in order to keep position accuracy Parameter x Integer number in range of from to 255 Motor current can be calculated using such equation 0 00835x A wm x Set motor current then it moves Parameter x Integer number in range of from to 255 Motor current can be calculated using such equation 0 00835x A wt Set motor current then controller operate in STEP DIR mode There is no automatic current control like stand by current in USB mode Current can be cut only by logic high on Enable input This applies only for 4ATT or SATT controllers with firmware version v7 or lower This command is absent for SATT and 6ATT controllers with firmware v8 and higher Parameter x Show controller settings related to Command mode Type this command only when using terminal and manual command entering This is the way to see fundamental settings in eye friendly fashion To get controller settings for software programming use p
65. tion against harmful interference in a residential installation This eguipment gene rates uses and can create radio freguency energy and if not installed and used in accordance with the instructions may cause harmtul in terference with radio communications However there is no guarantee that interference will not occur in a particular installation If this equip ment does cause harmful interference to radio or television reception which can be determined by turning the eguipment off and on the user is encouraged to try to correct the interference by one or more of the following measures e Reorient or relocate the receiving antenna e Increase the separation between the equipment and receiver e Connect the equipment into an outlet on a circuit different from that to which the receiver is connected e Consult the dealer or an experienced radio TV technician for help ALTECHNA is not responsible for any radio television interference caused by modifications of this equipment or the substitution or attach ment of connecting cables and equipment other than those specified by ALTECHNA The correction of interference caused by unauthorized modification substitution or attachment will be treated as responsibility of the user ATTENTION Cellular phones or other radio transmitters are not recommended to be used within the range of three meters of this unit since the electro magnetic field intensity may then exceed the maximum allowed d
66. to 255 Deceleration value 5 Integer from 1 to 65500 Speed value 6 Integer from 0 to 255 Motor motion current value 0 00835x A 7 Integer from 0 to 255 Motor idle current value 0 00835x A 8 Integer from 0 to 255 Motor current value in Step Dir mode 0 00835x A 9 Integer 1 2 4 8 or Micro stepping resolution value full half quarter eight or sixteen 10 Boolean 1 or 0 Motor enable motor is enabled if 1 and motor is disconnected if 0 11 Reserved 12 Boolean 1 or 0 Whether to reset position counter on each zero position switch press or no If this option is disabled 0 zero position button press does nothing to step counter If waveplate holder turned twice command o will show us that position is more than 15600 15600 is full waveplate turn in full stepping mode If this position is enabled 1 position counter will become 0 on each zero position switch press 13 Boolean 1 or 0 Whether to report coordinate then hitting zero position switch if 1 or do not report if 0 If this option is on 1 controller sends string Zp integer_position on each zero position button press Reserved Reserved Reserved Boolean 1 or 0 Motor direction setting in Step Dir mode motor turns clockwise if 17 parameter is 1 or counterclockwise if 17 is equal to 0 This setting is meaningful if parameter 20 is On www altechna com 19 Alte
67. tt Pilot cp210x device is assigned to ttyUSBO port There is also shown installation command for CuteCom package which is easy to use terminal application with GUI 6 4 SERIAL COMMANDS AND PROTOCOL Watt Pilot is a slave device according to computer and computer is a master device That means that PC sends data requests to attenuator and attenuator must respond Watt Pilot itself will never send data to computer without request except of two cases if Report zero position command zr setting is set also string USB Mode r n is sent upon con troller start if controller starts in Command mode Watt Pilot controller writes all received bytes to internal buffer If it re ceives carriage return symbol or w in C denotation 13 th symbol in ASCII table or OxOD in hex device will try to parse received bytes as a command string and will execute it Attenuator echoes back every byte it receives back to computer except for Symbol echoing is essential for users who literally type commands in terminal window This enables user to see what data is sent to device because not all terminal pro grams has a text field where sent symbols are shown mn OxOA symbol is treated like all other symbols Watt Pilot will respond to byte by sending additional data if com mand requires it Additional data is terminated with r n symbols Ter mination symbols r n are essential for users who lite
68. ture waveplate holder can have 36000 72000 144000 288000 576000 steps per full turn resolution No microstepping can cause motor resonance problems The higher the resolution the smoother and quieter motor is but motor torque and speed will decrease Half stepping resolution is used as default e Step frequency Motor step frequency so waveplate angular veloc ity can be changed Step frequency f Hz can have discrete vales such as 8000000 65535 n where n is integer in range of 1 64000 Wave plate angular velocity w degrees second is equal to w 360 k r f Pa rameter k is 15600 for standard attenuator and 36000 for big aperture attenuator Resolution divider r can be 1 2 4 8 or 16 as mentioned earli er in Resolution description Safe step frequency is 759 4 Hz optimized step frequency is 1224 2 Hz but can be tweaked for best performance e Accelerate and Decelerate If this option is set motor gradually acceler ates till maximum frequency is reached or decelerates till stop This can help to solve stall problems on worn out mechanics but causes motion to last longer These options should be unchecked for normal usage Default is unchecked e Overwrite Enable Input option is used in Step Dir mode only If checked voltage level on Enable pins 3 and 11 in DB15 connector is ignored and motor is enabled or disabled depending on selection to the right Ask document Watt Pilot
69. unctioning of Watt Pilot requires optimal configuration of optical elements regarding to incident laser beam polarization contrast Higher incident laser beam polarization contrast leads to higher Watt Pilot output polarization contrast Reflected s polarized laser beam Transmitted p polarized laser beam Figure 1 Watt Pilot operating principle Color differences shows intensity of laser beam Brighter red means more intensive laser beam 3 PACKAGING CONTENTS e Motorized attenuator e Controller e USB cable 2m length recomended but no longer than 3m e 12V power supply cable optional e Software installation instructions in USB flash e Two waveplate retaining rings with tightening key e Brewster polarizator holder optional 3 1 WATT PILOT MAIN COMPONENTS Optical components are placed into mechanical holders Main me chanical components of motorized Watt Pilot are shown in Figure 2 Waveplate mount is designed to fit 1 inch diameter waveplate mount Polarizer holder Depends from optics Figure 2 Watt Pilot main components Waveplate mount is attached to micro step motor Waveplate is fixed using two mounting rings seeFigure 3 Waveplate inside the waveplate holder is rotating around the optical axis of incident laser beam Step motor and waveplate mount are shipped together in one piece Polar izer s are placed into adapter for polarizer s Polarizer s to the mount are fix

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