71761_Applied_E g_Network_Final_Report
Contents
1. Blink LED to acknowledge action completed setlo FrontPanelLED7 ON setlo FrontPanelLED7 OFF go stateKey7 Wait end state stateKey7 Wait ifGet FrontPanelKey7 NO stateKeys end T ED Button 8 Increase the Manual Step Size by a factor of 10 state state_LED8IncreaseManualStepSizeChange modVar vPositiveManualStepSize 10 modVar vNegativeManualStepSize 10 Blink LED to acknowledge action completed setlo FrontPanelLED8 ON setlo FrontPanelLED8 OFF go stateKey8 Wait end state stateKey8 Wait ifGet FrontPanelKey8 NO stateKeys end Appendix D PID Motion Control Code Georgia Tech PID Motion Sequence Created by Alan Doolittle State Sequence Control Parameters declare ControlLoopIndex 0 declare DisplayLoopCounter 0 Start with system in manual mode 0 for development Change to auto 1 for runtime version declare Manual Auto 0 Motor Parameters Target Index for motor 1 declare vTarget Positionl 44000 Actual Index for motor 1 declare vCurrentPosition1 0 Step value for motor 1 declare vStep1 12000 Target Index for motor 2 declare vTarget Position2 44000 Actual Index for motor 2 declare vCurrentPosition2 0 Step value for motor 1 declare vStep2 12000 PID Parameters Prop unit is Int unit is seconds Der unit is fraction of int time NOTE Der should never exceed 0 25 or the system will begin to oscillat2. EPI RF Matching Network Ver 1 1 setlo FrontPanel LCD vLCD_BlankString setVar VLCD String Finding Home Wait30sec setlo FrontPanel LCD vLCD String Insure the torque limits are low enough to not damage the motors capacitors end stops setlo MTIAS SetTorqueLimits 3500 setlo MT2AS SetTorqueLimits 3500 Search for home position and reset the index to zero getlo MT2GS Position vCurrentPosition2 getlo MTIGS Position vCurrentPosition1 Tf the proper zeroposition was previously achieved current positions should be close to 0 Try to move the motors 22 turns in very slow mode setlo MTIAS RelativePositionSlow 88000 setlo MT2AS RelativePositionSlow 88000 Wait enough time for the motors to reach their limits Note this delay must be set to 24 if cap position is random During development this can be lowered to speed up initialization time delay 14 Should set index to zero for each loop However this is not currently working For 20 turn capacitors the max index should be 4000 x 20 80 000 getlo MT2GS Position vCurrentPosition2 getlo MTIGS Position vCurrentPosition If the proper zeroposition was previously achieved current positions should be close to 0 Note these routines are not currently working so comment them out setlo MT2AS ZeroMotorController setlo MTLAS ZeroMotorController delay 1 Update the display setlo FrontPanel LCD v
3. setlo FrontPanelLED4 OFF Toggle State off setlo MTIAS Velocity 0 go stateKey4 Wait end state stateKey4 Wait ifGet FrontPanelKey4 NO stateKeys end state stateLED5Change setlo FrontPanel LCD KEY 5 PRESS ifGet FrontPanelLEDS5 OFF stateLED5On go stateLEDSOff end state stateLED5On setlo FrontPanelLED4 OFF setlo FrontPanelLEDS ON setlo FrontPanelLED6 OFF setlo FrontPanelLED7 OFF setlo FrontPanelLED8 OFF Toggle State on setlo MTIAS Velocity 1500 go stateKey5 Wait end state stateLEDS5Off setlo FrontPanelLEDS OFF Toggle State off setlo MTIAS Velocity 0 go stateKey5 Wait end state stateKey5 Wait ifGet FrontPanelKey5 NO stateKeys end state stateLED6Change setlo FrontPanel_ LCD KEY 6 PRESS ifGet FrontPanelLED6 OFF stateLED6On go stateLED6Off end state stateLED6On setlo FrontPanelLED4 OFF setlo FrontPanelLEDS OFF setlo FrontPanelLED6 ON setlo FrontPanelLED7 OFF setlo FrontPanelLED8 OFF Toggle State on setlo MTIAS Velocity 500 go stateKey6Wait end state stateLED6Off setlo FrontPanelLED6 OFF Toggle State off setlo MTIAS Velocity 0 go stateKey6 Wait end state stateKey6 Wait ifGet FrontPanelKey6 NO stateKeys end LED Button 7 Reduce the Manual Step Size by a factor of 10 state stateLED7ReduceManualStepSizeChange modVar vPositiveManualStepSize 0 1 modVar vNegativeManualStepSize 0 1
4. automatic tuning aspect has been put on hold The theoretical implementation of TCP IP interface has continued though There have been very few tradeoffs at this time since as the budget demonstrates over 99 of the costs of parts are incurred by existing components Consequently while deciding which of the two optical detectors Digikey part s opt301 opt101 the opt101 was selected since it was a less expensive newer device that offered the same functionality as the opt301 It was also decided to prioritize the implementation of the optical detector in order to minimize the required code for plasma detection Design Alternatives and Tradeoffs There were a few design tradeoffs in our project that need to be addressed First was the decision to use active filters rather than passive ones to filter the analog inputs Then it was decided to use an optical sensor to detect plasma intensity The final decision was to use a clamping diode network like that used in the telecom industry The active filters were used for a number of reasons First the passive filters would have worked poorly with the output impedance of the detectors about 75 kilo ohms The 6 Hz cutoff was chosen so that the DC signal would not be attenuated while removing as much white noise from the plasma as possible Finally the boards which the filters were built on were provided and instructions were given to use them The optical sensor was chosen since it was inexpen
5. development It is Dr Doolittle s opinion that the IOC environment is not appropriate for a matching network application Never the less the following was accomplished under this program o Physical matching network was designed and shown to match to the Applied EPI plasma source o The Silvermax motors EPI desired to be used were incorporated on the matching network o Front panel code was implemented to move the motors select tune mode and interface with the user Example code is supplied in an appendix at the end of this report o PID control algorithms were implemented in IOC but the control loop delays inherent in the Applied EPI IOC environment made actual control of plasma s impossible this limitation was overcome in the Rabbit microcontroller implementation described in the next section Successful Rabbit Microcontroller Implementation Executive Summary The Inductive Nitrogen Plasma Source project aims to create an effective impedance matching network by minimizing the net reflected power within the system this results in a cost effective method of obtaining molecular nitrogen N utilized for semiconductor applications Initially the system attempts to inductively light the nitrogen based plasma next an optical sensor monitors the plasma source to determine whether it is lit or not Once the plasma is lit the system adjusts the servo motors which in turn vary the position of the oil filled capacitors to
6. go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateOutputControl Voltages lt lt lt LL lt lt lt LL lt lt lt L lt lt lt lt lt lt lt lt lt lt lt lt state stateOutputControl Voltages Update RF Power Control Voltages Add later Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 go stateMainLoop end This ruotine is not currently being used state stateNextPosition delay 0 2 getlo MTIGS Position vCurrentPosition1 modVar vTarget Positionl vStep1 modVar vStep1 0 5 getlo MT2GS Position vCurrentPosition2 modVar vTarget_Position2 vStep2 modVar vStep2 0 5 go stateUpdateMotorPositions end
7. lt lt state stateToggleCurrentMotor ifVar vCurrentMotor stateSetMotor2 modVar vCurrentMotor 1 Add turn LED off later go stateWaitToggleMotor end state stateSetMotor2 modVar vCurrentMotor 2 Add turn LED on later go stateWaitToggleMotor end state stateWaitToggleMotor Wait for Key to be released before returning to stateKeys ifGet FrontPanelAxisNext NO stateKeys end gt gt gt gt gt gt gt gt gt gt R DE lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt D L lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt D L lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateAddPosition If in Auto Tune Mode return to stateKeys without moving motors ifVar Manual_Auto 1 stateKeys ifVar vCurrentMotor stateAdjustMotor Positive ifVar vCurrentMotor 2 stateAdjustMotor2Positive message Error Program should never reach this point in stateAddPosition go stateKeys end state stateAdjustMotor Positive setlo MTIAS RelativePosition vPositiveManualStepSize setlo FrontPanel LCD Motor 1 PLUS go stateKeys end state stateA djustMotor2Positive setlo MT2AS RelativePosition vPositiveManualStepSize setlo FrontPanel LCD Motor 2 PLUS go stateKeys end state stateSubPosition If in Auto Tune Mode return to stateKeys without moving motors fVar vManual Auto 1 stateKeys ifVar vCurrentMotor stateA
8. motor 2 M2 M2 Decrements motor 2 Auto Manual Switches between automatic and manual MI tuning m we gt gt Auto Manual null Fig 4 Software Flowchart The final phase of the software project is the theoretical implementation of a TCP IP interface on the controller The controller will be configured to activate the TCP IP server and a Java applet will be developed to receive display and log information on the remote computer In addition it may be possible to manually tune a plasma remotely consequently the user will not have to physically enter the lab to monitor or adjust properties of the impedance matching system Project Goals The project goals consist of several items which include but are not limited to inductively lighting the plasma detecting the plasma by utilizing an optical sensor automated and manual tuning of the impedance matching system and if time permits logging the data through a TCP IP interface Technical Specifications Optical Sensor e SINGLE SUPPLY 2 7 to 36V e PHOTODIODE SIZE 0 090 x 0 090 inch e HIGH RESPONSIVITY 0 45A W 650nm e BANDWIDTH 14kHz at RF 1M e LOW QUIESCENT CURRENT 1204A Filters e 8TH ORDER BUTTERWORTH MULTIFEEDBACK FILTER e CUTOFF AT 6Hz e RESPONSE FREQUENCY 6 Hz e 1 RESISTORS e UNITY GAIN e IN SERIES WITH INSTRUMENTATION AMPLIFIER Controller e 800 watts RF Power supply e 15 volt power s
9. the appropriate impedance Impedance matching can be conducted in one of two ways manually or automated using a PID controller Due to time constraints only manual tuning has been accomplished Upon achieving successful impedance matching data logging must be taken into consideration In order to incorporate data acquisition a theoretical TCP IP interface is presented This project has several economic applications such as e Increasing the efficiency of the nitrogen source e Developing similar systems for other molecular gases e g Oxygen e Marketing this product to semiconductor research groups BAE university research Table of Contents Introduction 1 Project Description 2 Project Goals 5 Technical Specifications 6 Design Approach 6 Design Alternatives amp Tradeoffs 6 Tasks amp Schedule 9 Project Demonstration 10 Marketing Cost and Analysis 10 Summary amp Conclusions 15 Bibliography 17 Impedance Matching System WEB Appendix A Existing Controller Code WEB Appendix B Optical Sensor Description Appendix C TCP IP Theoretical Implementation Appendix D Introduction This project is designed to create a matching network for a nitrogen plasma source Nitrogen typically exists as a molecular compound N2 and is not reactive in most situations to achieve a plasma state the molecules are split into atomic nitrogen Splitting is typically achieved by applying significant amounts of heat however this is not a practical a
10. Applied EPI RF Matching Network Final Report Due Date March 31 2004 Dr W Alan Doolittle The work proposed was to implement an auto tuning RF matching network for a Applied EPI plasma source The work originally was to be implemented in a custom microcontroller system based on the Rabbit microcontroller family After program initiation Applied EPI expressed reservations regarding this approach based on concerns of the lack of experience with this platform and thus the inability to field and support this implementation Thus substantial effort was set forth to re engineer the tuning network within the proprietary IOC controller format developed by Applied EPI To this end this report details both implementations Proprietary IOC Applied EPI Implementation In short the IOC implementation worked to move motors and tune the capacitors in the matching network but fundamental limitations in the IOC environment prevented full implementation The IOC environment was found to be very unstable with the EPI controller locking up without notice and very frequently Furthermore the slow response of the EPI system prevented real time feedback of the motor plasma conditions and resulted in an in effective matching system Furthermore the Silvermax motors requested by EPI to be used were discontinued mid stream in the project due to patent infringement accusations and thus it was not possible to get replacement parts necessary to continue this thread of
11. Direct Connection Procedure Overview details in 3 Section 5 2 5 2 1 How to Set IP Addresses in the Sample Programs With the introduction of Dynamic C 7 30 we Z World have taken steps to make it easier to run many of our sample programs You will see a TCPCONFIG macro This macro tells Dynamic C to select your configuration from a list of default configurations 3 5 2 2 How to Set Up your Computer s IP Address for a Direct Connection Click on Start gt Settings gt Control Panel to bring up the Control Panel and then double click the Network icon Depending on which version of Windows you are using look for the TCP IP Protocol Network gt Dial Up Connections Network line or tab Double click on this line or select Properties or Local Area Connections gt Properties to bring up the TCP IP properties dialog box You can edit the IP address and the subnet mask directly Disable obtain an IP address automatically You may want to write down the existing values in case you have to restore them later It is not necessary to edit the gateway address since the gateway is not used with direct connect 3 e 5 2 3 Run the PINGME C Demo Flow Chart of theoretical TCP IP implementation process flow from top to bottom ag Direct Connection of PC to Smart Indirect Connection of PC to Star CPU Card via Ethernet Smart Star CPU Card via crossover cable Internet Run Dynamic C 7 30 Run Dynamic C 7 30 TCPCONFIG macro TC
12. LCD_BlankString setlo FrontPanel LCD EPI RF Matching Network Ver 1 1 Initialize the Keypad front panel setlo FrontPanelLED1 OFF setlo FrontPanelLED2 OFF setlo FrontPanelLED3 OFF setlo FrontPanelLED4 OFF setlo FrontPanelLEDS OFF setlo FrontPanelLED6 OFF setlo FrontPanelLED7 OFF setlo FrontPanelLED8 OFF Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateReadConfigInformation lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateReadConfigInformation Read configuration variables from disk Future expansion Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateDetermineKeyStatus KILLI state stateDetermineKeyStatus Read keypad status add Key dispursement routines later Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateReadVoltages lt lt lt lt lt lt lt lt lt c lt lt lt lt lt lt l
13. PCONFIG macro Run PINGME C Ping test Run PINGME C Ping test Respective Sample Programs depends on application Run STATE C Run SSI C Respective Sample Programs depends on application Appendix C Front Panel Control Software Georgia Tech keypad control sequence based on code developed by Ralf Hermann This sequence uses the same branch return control as the main motion sequence Be sure to read precautions in motion control sequence before modifying declare KeypadControlLoopIndex 0 Start with system in manual mode 0 for development Change to auto 1 for runtime version declare vManual Auto 0 declare vLCD help declare vPositiveManualStepSize 500 declare vNegativeManualStepSize 500 declare vCurrentMotor 1 declare vAutoPreset1 declare vAutoPreset2 declare vPreset11 declare vPreset12 declare vPreset21 declare vPreset22 declare vPreset31 declare vPreset32 state stateKeys ifGet FrontPanelKeyl YES stateLED1Preset1 Change ifGet FrontPanelKey2 YES stateLED2Preset2Change ifGet FrontPanelKey3 YES stateLED3Preset3 Change ifGet FrontPanelKey4 YES stateLED4SaveCurrentStateChange ifGet FrontPanelKey5 YES stateLED5IgniteModeChange ifGet FrontPanelKey6 YES stateLED6ExtinguishModeChange ifGet FrontPanelKey7 YES stateLED7ReduceManualStepSizeChange ifGet FrontPanelKey8 YES stateLED8IncreaseManualStepSizeC
14. SSI C how to make Smart Star CPU card a web server allows user to remotely turn the LEDs on amp off TCP_RESPOND C amp TCPSEND C allows the remote user to a send data from the remote program to the Smart Star CPU card b receive data from the CPU card Integrated programs for TCP IP implementation cont e echo c Demonstrates the tcp_listen call A basic server that when a client connects echoes back to the client user any data that they send Can be configured to listen on different TCP ports state c Demonstrates building a state machine based Internet server i e Java Applet According to zworld com prior to using this program study the usage of sock_dataready and sock_fastwrite here when implementing your own server e ftp client c This program utilizes the Rabbit FTP client library It passes all your parameters to ftp_client_setup in the form of a file which opens a connection and the library will download the file If successful it displays the file otherwise the error code Therefore this program can be used to upload a file to the existing impedance matching system thereby allowing the user to remotely input data parameters i e motor positions e dac ctrl c Provides a Java applet to contro DAC s digital analog converters Includes Java source and byte code files Reference 3 in Bibliography Tech Support www zworld com support
15. djustMotorl Negative ifVar vCurrentMotor 2 stateAdjustMotor2Negative message Error Program should never reach this point in stateAddPosition go stateKeys end state stateAdjustMotor1 Negative setlo MTIAS RelativePosition vNegativeManualStepSize setlo FrontPanel LCD Motor 1 Minus go stateKeys end state stateAdjustMotor2Positive setlo MT2AS RelativePosition vNegativeManualStepSize setlo FrontPanel LCD Motor 2 Minus go stateKeys end gt gt gt gt gt gt gt gt gt gt R DE lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt LED 1 In Manual Mode goto preset 1 lt lt lt lt lt lt lt lt lt lt lt lt lt lt gt gt In Autotune Mode use preset one to move to when extinguishment is detected lt lt DSSS gt gt gt SSS SSDS SSD DD SS SD DDD DDS DDD DD DD DDD DD OOK KKK lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateLED 1 Preset 1 Change setlo FrontPanelLED1 ON setlo FrontPanelLED2 OFF setlo FrontPanelLED3 OFF fVar vManual Auto o stateSetPreset 1 Manual go stateSetPresetl Auto end state stateSetPreset 1 Manual Set Preset 1 setlo FrontPanel LCD Moving to Preset 1 setlo MTIAS Position vPresetl 1 setlo MT2AS Position vPreset12 go stateKey1 Wait end state stateSetP
16. e PID for Motor 1 declare Prop1 5 0 declare Intl 5 0 declare Der1 0 125 declare OutputPercentagel 0 0 PID for Motor 2 declare Prop2 5 0 declare Int2 5 0 declare Der2 0 125 declare OutputPercentage2 0 0 Plasma Variables Track Plasma Condition 0 plasma off 1 plasma on 1 plasma extinguish detected 2 plasma ignition detected declare vIgnitionCondition 0 declare vForwardPower 100 0 declare vReversePower 1 0 declare vPhaseError 5 0 declare vMagnitudeError 2 0 declare vReflectionCoef 100 0 declare VVSWR 100 0 Display Variables declare vLCD_String EPI RF Matching Network Ver 1 1 declare VLCD_BlankString gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt DD DD DDD DD DDD OO lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt L lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateMainLoop lt lt LLL lt lt LLL lt lt LLL lt lt LLL lt LL L lt lt LL L lt lt lt lt lt lt lt lt lt DRE lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateMainLoop This sequence handles the main switching looping between states The loops are repeated by branching to various
17. ed this will conclude the hardware phase of the project Upon completion of the hardware phase software was implemented to control the impedance matching system there are three phases of software design manual tuning automatic tuning and data acquisition through theoretical TCP IP interface Referring to Figure 3 manual tuning involves slowly ramping the LCD power of the RF power source while a LED manually adjusting the motors using Control Buttons M1 M1 M2 M2 Auto Manuel the LCD buttons to minimize reflected power This is similar to most manual controllers in the way it minimizes reflected power The forward reflected and total power will be displayed on the LED display so the user can minimize the reflected power The far left LED will light when a plasma is detected by the optical sensor The second phase of the code will allow the controller to automatically tune a plasma based on the inputs from the RF sensor If the automatic tuning fails then a push button on the front of the display can be used to switch back to the manual tuning mode Once the user has tuned the plasma the same button can be pressed to set the controller back to an automatic mode This implementation can be seen in figure 4 null Yellow Currently implementing Key Green Provided Red Not to be implimented 0 Five buttons in use MI Increments motor 1 Ml1 MI Decrements motor 1 M2 Increments
18. hange ifGet FrontPanelKeyPlus YES stateAddPosition ifGet FrontPanelKeyMinus YES stateSubPosition NOTE The key labeled FrontPanelAxisSelect actually controls the Manual to Autotune function ifGet FrontPanelAxisSelect YES stateManualAutoToggle ifGet FrontPanelAxisNext YES stateToggleCurrentMotor Sub states below stateKeys that service the keypad branch back to stateKeys Thus all keys are poled and serviced before returning to MainControlLoop go MainControlLoop end gt p gt gt gt gt gt 2222222222222 2222222222222 2222220 GGG GGG KIILI IKII III DR R DE lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt D L lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateManualAutoToggle fVar vManual Auto 0 stateSetAutoTuneMode modVar vManual Auto 0 Add turn LED OFF later go stateWaitToggleMotor end state stateSetAutoTuneMode modVar vCurrentMotor Add turn LED on later go stateWaitManualAuto end state stateWaitManualAuto Wait for Key to be released before returning to stateKeys ifGet FrontPanelAxisSelect NO stateKeys end gt gt gt gt gt gt gt gt gt gt R DE lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt D YE lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt gt gt gt gt gt gt gt gt gt gt R DE lt lt lt lt lt lt lt lt lt lt lt lt lt lt
19. is also an RF sensor which provides all the necessary information about the current state of the RF signal including measuring forward and reflected power The RF detector inductive coil and capacitors compose the RF network gt Inductive Plasma Source Optical Sensor RF Power Controller power A D Controller RF Power Power Control Motor 2 D A Controller Controller xpansion board RS 232 Control Figure 1 Layout of matching network with controller All of these devices digital controller RF power supply capacitors inductor motors RF sensor have been provided prior to the beginning of this project There was also a reasonable amount of base programming provided to achieve many of the desired functions which include Inductor e enabling the controller to communicate with the motors e acquiring inputs from the controller s A D converters e sending output from D A converter The equipment design begins with the filters amp amplifiers which are utilized to condition the inputs from the RF sensor Next an optical detector was constructed to indicate whether the plasma is lit see Appendix C Also a clamping diode network was implemented to protect the filter used by the optical detector from any stray power induced by the optical detector s proximity to the plasma source Once these devices are built they must be installed in the controller box and wired into the existing system Once install
20. l the RF power supply to ramp power to the system all specifications can be found in the Smart Star manual 3 The Smart Star uses C as its programming language Finally the RF sensor which measures forward and reflected power was obtained from RF Services Part Number 232017 04 in addition the RF sensor provides the majority of the inputs forward and reflected power and phase and magnitude error to the controller Many of the RF sensor s specifications are within its manual 4 except for the range of the output values Pictures of these components can be seen in Appendix A The website contains the current C code for the system The three preliminary steps 1 manual control coding 2 filter design and construction and 3 optical filter design and implementation must all be complete before testing of the manual code can commence Once the boards have been wired into the controller Figure 1 it will be possible to calibrate the received signals in the code and test the manual code Figure 3 on the plasma source Although testing can be conducted without the optical sensor this would require significantly more coding time It was planed that once testing and calibration is complete with the manual tuning code work on the automatic tuning code can begin simultaneously with the theoretical TCP IP implementation Due to problems with the system on which the plasma controller operates the controller has not been calibrated so coding of the
21. ng function calls as necessary In addition due to time constraints a theoretical TCP IP implementation was researched refer to Appendix D Based on the application of any component within the overall system a complex expensive device is NOT necessarily superior to the simpler less expensive device i e Always strive to utilize the most practical implementation not necessarily the most sophisticated one Moatasm in regards to the optical sensor However more expensive filters were necessary in designing the filters and disused in the design tradeoffs The project demonstration went well All the components operated within desired parameters The RF sensor outputs have negative and positive outputs which were designed to range from 15 volts to 0 volts and 15 volts to 0 volts respectively but require a range from 15 volts to 15 volts Bibliography 1 SilverMax Command Reference QuickSilver Controls Inc Tech Rep Revision 4 00 Dec 2002 2 SilverMax User Manual QuickSilver Controls Inc Tech Rep Revision 3 21 Mar 2002 3 Smart Star SR9000 User s Manual Z World Inc Davis CA Tech Rep Part Number 019 0107 020301 A 2002 4 Manual for RF Input Detector RFS Part Number 232017 04 RF Services Inc Sunnyvale CA Tech Rep Document No 232527 04 Rev A 1998 Appendix A Optical Sensor Description Purpose Optical sensor utilized to detect whether plasma is li
22. nication issues a data entering amp logging process will be implemented theoretically via a TCP IP interface see Appendix D This device has many advantages over tuning a plasma by hand It is ability to automatic tune a plasma its implementation of a TCP IP interface to monitor the plasma outside of the lab As well as its ability to assist in manually tuning a plasma by having predefined set points for lighting the plasma which are programmed into the controller Project Description To achieve control of the above mentioned impedance matching system a digital controller for a nitrogen plasma source is being constructed Figure 1 Figure 2 shows the schematic of the matching network In addition the digital controller see Appendix A has been provided however its programming was incomplete as were parts of the signal input system for the controller The plasma source is based on an inductor containing a tube through which molecular nitrogen can flow The inductor is in parallel with one capacitor and in series with another forming a matching network As depicted in Figure 2 a high power RF signal is sent through the circuit To form an efficient plasma the RF power source supplies maximum power to the gas amp the impedance of the power supply is matched to the plasma source Matching the impedance is accomplished by using variable capacitors in the matching network as seen in Appendix A which are tuned by independent motors There
23. pproach for nitrogen so a plasma source is utilized A plasma is generated by passing an RF current through an inductor which encompasses the gas next once the appropriate magnetic flux is flowing through the gas the plasma is sparked It is necessary to get the power to flow through the gas as opposed to reflecting back at the source The inductive impedance is determined by the type of gas its pressure amp density and the natural impedance of the inductor The impedance matching system consists of a Smart Star Control Unit an RF detector D A and A D converters 8th order Butterworth filter Monolithic Photodiode and Single Supply Transimpedance Amplifier optical sensor 2 servo motors designated to control the impedance of a network of oil filled capacitors and 2 power sources Theoretically impedance matching is achieved by adjusting the servo motors to synchronize the oil filled capacitor s impedance to that of the plasma the impedance of the plasma can be matched manually or automatically utilizing C code see Figure 3 and Appendix B Once the impedance is matched the plasma can be ignited Therefore to allow manual and automatic impedance matching capacity this project will implement matching algorithms and a power controller to compensate for the remaining reflected power In addition an optical sensor will be utilized to determine if the plasma is lit Finally due to time constraints and unexpected motor commu
24. resetlAuto Set Preset used when the plasma extinguishes to manual preset 1 setlo FrontPanel LCD Auto Using Preset 1 modVar vAutoPreset1 vPreset1 1 modVar vAutoPreset2 vPreset12 go stateKey1 Wait end state stateKey 1 Wait Wait for Key to be released before returning to stateKeys ifGet FrontPanelKey1 NO stateKeys end LED 2 Increase Manual Step Size by a factor of 10 state stateLED2IncStepChange ifGet FrontPanelLED2 OFF stateLED2On go stateLED2Off end state stateLED2On setlo FrontPanelLED2 ON go stateKey2 Wait end state stateLED2Off setlo FrontPanelLED2 OFF go stateKey2 Wait end state stateKey2 Wait ifGet FrontPanelKey2 NO stateKeys end state stateLED3 Change setlo FrontPanel LCD KEY 3 PRESS ifGet FrontPanelLED3 OFF stateLED3On go stateLED3 Off end state stateLED3On setlo FrontPanelLED3 ON go stateKey3 Wait end state stateLED3 Off setlo FrontPanelLED3 OFF go stateKey3 Wait end state stateKey3 Wait ifGet FrontPanelKey3 NO stateKeys end state stateLED4Change setlo FrontPanel LCD KEY 4 PRESS ifGet FrontPanelLED4 OFF stateLED4On go stateLED4Off end state stateLED4On setlo FrontPanelLED4 ON setlo FrontPanelLEDS OFF setlo FrontPanelLED6 OFF setlo FrontPanelLED7 OFF setlo FrontPanelLED8 OFF Toggle State on setlo MTIAS Velocity 3000 go stateKey4 Wait end state stateLED4Off
25. sive and easy to implement while reducing the complexity of the code It allowed the system to optically detect a plasma rather than using impedance calculations to do so This feature also gave the system the ability to give the user an actual plasma intensity which is useful to know relativity how much atomic oxygen being produced Summary amp Conclusions The design of the inductive nitrogen plasma source in summary is composed of three main components inductive plasma source controller and RF network The RF detector inductive coil and capacitors compose the RF network the op amps power supplies rabbit controller clamping diode network and filters are in the controller and the optical sensor is found within the plasma source module Also an important goal which was successfully completed was to incorporate the optical sensor and op amp filters into the existing hardware The filter an eighth order multiple feedback Butterworth filter with cutoff frequency at 6 Hz was designed In conjunction with designing the filter an appropriate optical sensor was chosen to fit our application Furthermore the designs for the op amps were completed and reviewed Next construction of op amp boards began and is completed Simultaneously with the above mentioned tasks designing filter choosing optical sensor ordering parts ongoing work was conducted on coding which consists of debugging the existing motor control systems and modifyi
26. states The state then increments the ControlLoopIndex and branches back to mainloop Using this approach be sure that all branchs and sub branches away from this MainLoop end in an increment to ControlLoopIndex and then return to MainLoop ifVar ControlLoopIndex lt 0 stateReadConfigInformation Reading and updating Configuration data ifVar ControlLoopIndex lt 1 stateStartupSequence Initializing and Homing motors ifVar ControlLoopIndex lt 2 stateDetermineKeyStatus Checking Keypad ifVar ControlLoopIndex lt 3 stateRead Voltages Reading RF Sensor Voltages ifVar ControlLoopIndex lt 4 stateCalculatePID Values Updating PID parameters ifVar ControlLoopIndex lt 5 stateUpdateMotorPositions Updating Motor Positions ifVar ControlLoopIndex lt 6 stateOutputControlVoltages Outputing RF Power Control Voltages Since updating the display is low priority only update the display every 5 iterations modVar DisplayLoopCounter 1 ifVar DisplayLoopCounter gt 4 stateUpdateDisplay Loop through again skipping initialization steps modVar ControlLoopIndex 2 end DDS SPSS SSP SSS SPS SS SPS SS SSS SS SS SS SS SS SO OO lt lt NCCC OC lt lt lt L lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt End stateMainLoop LLK LL lt LL lt lt l
27. t lt lt lt lt lt lt lt lt lt lt lt lt lt state stateRead Voltages Read RF Sensor Voltages Add later Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateCalculatePID Values EE EE GG AAAI OM OES 7 state stateCalculatePID Values Update PID loop parameters Add later Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateUpdateMotorPositions RRR RR ee RS state stateUpdateMotorPositions Update Motor Capacitor Positions setlo MTIAS Position vTarget_Position1 setlo MT2AS Position vTarget Position2 delay 0 1 Ta the final runtime version the PID algorythm will continuously update and zoom in on the setpoint Thus no wait for position statements are required Inthe debug use a hard delay delay 1 getlo MTIGS Position vCurrentPosition1 ifVar vCurrentPosition l 5 vTarget Positionl stateWaitForPosition2 getlo MT2GS Position vCurrentPosition2 ifVar vCurrentPosition2 5 vTarget Position2 stateNextPosition Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1
28. t lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt DDS SPSS SSP SSS SPS SS SPSS SS SSS SSS SS SS SS OO lt lt lt LLK lt lt lt L lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateUpdateDisplay lt lt lt lt lt lt LL lt lt lt L lt lt LL lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateUpdateDisplay Fill in details later for various display options VSWR mag phase phase x VSWR DI setVar vLCD_ String modVar vLCD_String Pow modVar vLCD_ String vForwardPower modVar vLCD_String F modVar vLCD_ String vReversePower modVar vLCD_String R modVar vLCD_String OutputPercentage1 modVar vLCD_String modVar vLCD_String OutputPercentage2 setlo FrontPanel LCD vLCD_String Increment the mainloop index and return to stateMainLoop modVar ControlLoopIndex 1 modVar DisplayLoopCounter 0 go stateMainLoop end gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt gt stateStartupSeguence lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt lt state stateStartupSequence Mnitialize the Display setlo FrontPanel LCD
29. t or not Source www ti com Schematic e Pin1 V 15V e Pins 4 amp 5 shorted output pins Pins 3 amp 8 grounded NOT USED Pins 2 Testing To test the operation of the optical sensor a voltmeter was connected to the output amp an observance of the sensor s response to different ambient light stimuli light dark revealed Pin 5 connected alone produced digital output 0 V or 15 V Pin 4 amp 5 shorted results in analog output range 0 15 V Conclusion Analog output allows user to differentiate between a bright inductively coupled plasma and a dim capacitively coupled one Appendix B TCP IP Theoretical Implementation Purpose A TCP IP interface provides remote data input and acquisition capability v Specifications e Smart Star SR9000 our controller top picture Contains a TCP IP port bottom picture Network can be setup as VPN Virtual Private Network or via nternet e When a direct connection is made the interface must perform ping test SR9150 IP 10 10 6 101 m card Netmask 255 255 255 0 User s a crossover cable Direct Connection PC to Smart Star CPU Card green LNK light on CPU card Ethernet connected orange ACT light data transfer e Ping test and upcoming Smart Star integrated programs i e provided by manufacturer are run in Dynamic C Integrated programs for TCP IP implementation e
30. upply e 24 volt power supply e Rabbit Smart Star 9000 controller Matching Network e Oil filled Capacitors have gt 80000 settings e RS232 communication with Servo motors Design Approach The initial design is split into three parts 1 The design and construction of the filter and amplifier boards 2 The selection of the optical sensor and the construction of its clamping diode network 3 The coding of the manual tuning system and later the auto tuning and TCP IP features The design of the filter and amplifier boards has been completed using an eighth order Butterworth filter Figure 5 and the parts are being ordered An optical detector has also been selected for its compact size and Figure 5 Eighth order filter its high selectivity within the infrared range making plasma detection and signal filtering more effective The existing design uses two SilverMax servo motors which are set up in a stepper mode This configuration was chosen to take advantage of the ease of control of the stepper motor and the speed of the servo motor All the information about the motors function and interface are provided in two manuals Command Reference 1 and User Manual 2 The motors are set to communicate in RS 232 mode for easy interface with the Smart Star digital controller This controller will also receive all the information from the amplifier and filter boards through its A D converters and will contro
Download Pdf Manuals
Related Search