High-Voltage Supply Controller Software (for
Contents
1. High Voltage Supply Controller Software for PRESAM PLER and BPC User M anual and Reference v1 1 Henk Boterenbrood NIKHEF H Amsterdam January 1995 CONTENTS As Orao sce che esi et eh Sate a a ok ts ri eee ee Sete ace 1 2 BA CO ts 1 3 Automatic trip COV FY ai aora pela Gan ieee ghana Saat 3 4 Command reply protocol 22 225 is 4 4 1 Controller operation examples ss s sssssssssrssesrssssirsnrsnenininnnnnnnnnnnnnnnnnennnnnnnanenna 5 5 Calibration of the powersuppli8S oocoocicicicnococococononocnnorennncncrnencnnn roce rnnrr rre rare 6 6 Controller ComMMandS e555 sessed tons cok idea 8 6 1 Commands for normal OPeratl ON eeceeeeteeeeeseeeeeeeseeeeetseaeeeeeteseetenetatneeaes 9 is lo ae aaa 9 612 26rt catenin one eee A 10 CDS ada ninos add isc eth 10 A Fores ora ee E aaa 10 PPP tes acetate ls as 10 CON castes titer ass a a a ar Rea eae 11 NU RC a atu ahs casa O 11 UV ose stress aac cate cat ete es en eect easiness 11 VD NG ase oes ae cose ico tec sen wae tate eae ade ca seme te 12 WOR og ttters ease E ae ee 12 6 VIBRA sa a e cai cae ke A meen deme es 12 CR ae 13 GAS RSS cate otis ah ee eee Sitesi i wae tote te ce ee ee 13 LARS Eee aR a ee 14 A ease sia apn ota cease eee eet 14 DTG VO eae aa seat es ats stasis ce ete ents ede Aaa T 15 A A alse sacs ee oe eee eA 15 61 18 A este ai Seatece ta A neem tart ahha RA 15 o A ae ceca T 15 6 120 SM T at ate aa Decana pais 16 GU PL A A es eee ems 16 6122 SOP2. A A a a a a a 16 DS A O E E E a no a 16 GLANS aa a cet ee tee A aa 17 A a a a estes O es 17 6 2 Commands for calibration s ssssssssssssssisrssrsrssinrsnrsneninitnnnnnntnnnnnnrannnnnnnnnnnnnnnnnna 18 O2ICA OE E E ta ide oe 18 602 ZCA ea O a R R 18 PAE E A VA E A E ee e eeaoe ae 18 A E a 19 A AP eae toe See hace eee T 19 NB 2G Oe aces ac eats te a ease eines 19 A A a eae eae 20 6 2 8 DO ISIC Sra re tes bee 20 02 E D SI sico nado ete nea ta didas adas 21 6210 SV P cata ratte Gi ee a Ane aes ee eae canst 21 o ree te aes eed ae ree ae eee ree ee A 21 6 3 CON to te beicon 21 T Error NUMP S uo dd odioso mad dad aa 22 8 Running code from EPROM or EEPROM ccccsseeeseeeeeeseeeteeeeeeseeneneeaeaeeeeeeesaeenena 24 9 Default o cde lec cetera a deck wee eet ado aie ay eee ee ee 26 High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 1 Introduction This document is a reference and a user manual for the software running on the 80C552 microcontroller which forms the heart of the high voltage powersupply module which was developed to supply high voltage to the photomultiplier tubes PMs of the Presampler PRES and the Beam Pipe Calorimeter BPC which form parts of the ZEUS detector at DESY Hamburg Hardware and software are entirely based on a design for the Small angle Rear Tracking D etector SRTD The normal user should be aware that this document contains much more info
3. see ENA according to the set voltage measure and control frequencies defined see SVO SSF SCF If the powersupply still has to be set to the desired voltage when the control process is started the control process will wait a certain period of time as defined by the set control delay see SCD in order to let the voltage settle before starting to regulate it High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 1 2 DEE command P1D EE reply p1D EE M akes the program stored in EEPROM invalid subsequent SWI commands do not work anymore until a new program is downloaded 6 1 3 DIS command P1 2DIS reply p1 2DIS Disables one powersupply or all HV supplies if the wildcard is used the DACs for this supply are set to zero 6 14ENA command P1 2ENA reply p1 2ENA Enables one powersupply or all HV supplies if the wildcard is used If the control process is active it will take care of setting the voltage to the required value If the control process is not active the voltage will go to a value corresponding to a DAC value of zero or to a value previously set with theSVO command The auxiliary powersupply is not controlled by the control process and thus gets immediately set to its requested voltage when it is enabled or by the SVO command independent of the control process 6 1 5 HLP command P1HLP reply lt version_number gt lt list_of_mnemonics gt p1 HLP The version num
4. was detected in a line of the downloaded Intel hex format file HEX_NO_CODE The user issued the command to switch to the program in EEPROM but no valid program is present in EEPROM HEX_INCOMPLETE The downloaded Intel H ex format file did not have a proper end of data line 12C_ TIMEOUT A timeout occurred on receiving an acknowledge on the on board 12C bus 12C_ STATUS An incorrect status was detected during an on board 2C bus operation LINE TOO LONG The command line received by the controller is longer than the controller can store the line length is limited to 50 characters including lt CR gt High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 LINE INCOMPLETE Somehow the lt CR gt of the command line is lost ERROR_IN_ADDRESS The address of the addressed supply supplies in the commandline is incorrect for the given command ERROR_IN_PARAMETER A parameter in the command line is incorrect PAR_OUT_OF RANGE A parameter in the commandline is outside ts valid range ILLEGAL_CMD The command given in the commandlineis valid but illegal in this mode version of the program UNKNOWN_CMD The command given does not occur in the list of available commands 8 Running code from EPROM or EEPROM If aversion of the HV supply controller software is produced it is important to know whether the code will be stored in EPROM 32 or 64 KByte or EEPROM 3
5. 0H 80C552 port P1 switch_program CPL PIO 3 END and the following code to be able to switch from EEPROM to EPROM PUBLIC switch_program ASEG ORG OFFFEH 32K EEPROM mirrored in 08000H OFFFFH PIO DEFINE 090H 80C552 port P1 switch_program CPL PIO 3 END If the above directions are followed the user can safely switch from the program version in EPROM to the onein EEPROM and back High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 9 Default Settings When no settings are ever saved the default settings are sample frequency control frequency control delay requested high voltage auxiliary supply voltage 75 maximum allowed current load 100 0 and maximum number of trips and hardwired in the code minimum high voltage to set maximum high voltage to set minimum sample frequency maximum sample frequency minimum control frequency maximum control frequency range of no adjustment to voltage range of allowed measured voltage range of allowed set voltage 10 0 Hz 10 Hz 3 S 1000 V V UA 1 800 v BPC 600 V 1200 V BPC 1000 V 10 Hz 20 0 Hz 0 1 Hz 100 Hz measured voltage requested voltage 0 3V measured voltage required ADC count 50 ca 20V set voltage requested voltage 50V
6. 2 KByte in other words whether the code is to be the default running code when the controller is switched on or whether the code is downloaded by the user and then run by issuing the command SWI N ote that downloading needs to be done only once but to run this code after switching on the controller the SWI command has to be given first to switch from the default program in EPROM to the version that was previously downloaded to EEPROM In global h when running from EPROM the following definition has to be present to protect against switching to an empty EEPROM or downloading codeto EEPROM when therunning program itself is already stored in EEPROM overwriting itself define RUNNING EEPROM 0 and when running from EEPROM define RUNNING EEPROM 1 High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 In order to be able to make a distinction between versions it is recommended to change the version number in hv_main c to a unique number In the example below the version is set to a b char version Oxab The current version number can then be obtained using command RPS M odule switch s03 should contain the following assembler code to be able to switch from EPROM to EEPROM Note in case of a 32 KByte EPROM or EEPROM the code bytes have to be put in the H EX file by hand at address O7FFEH PUBLIC switch_program ASEG ORG OFFFEH 64K EPROM or 32K mirrored in 08000H OFFFFH PIO DEFINE 09
7. D_CURRENT READ_DARKCURRENT READ_PROCESSOR STATUS READ _SUPPLY_ALL READ_SETTINGS READ _SUPPLY_STATUS RESET READ VOLTAGE ADC READ_VOLTAGE SET_CONTROL_DELAY SET_CONTROL_FREQUENCY SET_MAXIMUM_CURRENT SET_MAX_TRIPS SPY_MODE SET_SAMPLE_ FREQUENCY SET_VOLTAGE SAVE SETTINGS SWITCH_PROGRAM High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 CALIBRATE_CURRENT CALIBRATION _MODE CALIBRATE_VOLTAGE DELETE_PARAMETERS GET_CURRENT GET_VOLTAGE READ_PARAMETERS SET_DAC_COARSE SET_DAC_FINE SAVE_PARAMETERS A description and explanation of each command with examples using PRES HV controller address 1 and powersupply address 2 follow It is always possible to use a wildcard for the HV controller address except for the HLP command for some commands it is not allowed to use a wildcard as a power supply address and for several commands the use of a powersupply address is meaningless altogether and is then left out The cases where a command returns an error are not considered here see section 7 for a description of possible error conditions 6 1 Commands for normal operation 6 1 1CTR command P1CTR1orP1CTRO reply p1 CTR 1or p1 CTR 0 Switches the control mode on or off if the parameter in the command is 1the control process is started if it is Othis process is stopped Supplying a powersupply address is meaningless The control process measures and adjusts the HV supplies that are enabled
8. Default spy mode is off 6 1 22 SSF command P1SSF100 reply p1 SSF 100 Sets the frequency with which the voltage and the duty cycle of the active supplies are sampled The required frequency should be multiplied by a factor of 10 In the example above the sample frequency is set to 10 Hz Supplying a powersupply address is meaningless the sample frequency applies to all supplies controlled by this HV controller including the auxiliary supply 6 1 23 SVO command P1 25V O 1120 reply p1 25V O 1120 Sets the required voltage for the stated powersupply to the stated value in Volts The DACs for this supply are set to the proper values unless the High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 control process is active and the supply is a HV supply then the control process will take care of setting the voltage A wildcard for the powersupply address is allowed then the voltage setting applies to all HV supplies 6 1 24 SVS command P1SVS reply p1SV S 100 10 2 800 70 1000 1000 1000 1000 1000 1000 1 Saves the current general settings in EEPROM for permanent storage so that from now on they will be the current values after every subsequent power up reset The command returns the saved current settings being the sample frequency Hz 10 the frequency of regulating H z 10 the control delay s the maximum current load uA 10 the required voltages for all supplies the auxiliary s
9. The values returned are respectively the supply status last measured average voltage V requested voltage V last set voltage V minimum measured voltage V maximum measured voltage V last measured average current load uA 10 minimum measured current load uA 10 maximum measured current load uA 10 the currently valid dark current A DC units the trip counter of this supply and the last error status that occurred High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 1 12 RSE command P1IRSE reply p1 RSE 1 100 10 2 1000 75 1020 1020 1020 1020 1020 1020 2 Returns the current settings being controlprocess on off O off 1 on the sample frequency H z 10 the frequency of regulating Hz 10 the control delay s the maximum current load uA 10 the required voltages for all supplies the HV supplies and the auxiliary supply in Volts and the number of consecutive trips after which a HV supply will beswitched off permanently no automatic trip recovery anymore Supplying a powersupply address is meaningless N ote that the current frequencies are multiplied by a factor of 10 In the example above the frequencies are 10 Hz and 1 Hz respectively and the control delay is 2 seconds the control process will wait 2 seconds in order to let the voltage settle before starting to regulatethe supply voltage if the control process is active the maximum current loa
10. address of the HV controller 0 255 if all HV controllers were addressed by means of a wildcard every individual HV controller will send a reply m number of the powersupply on this HV controller the command applied to 0 1 2 or meaning all high voltage powersupplies number 0 is the High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 auxiliary supply if the preceding period and M werenot present in the command in the reply m will bea wildcard character cmd the same three letter command mnemonic if the command was processed successfully ERR otherwise parl par2 return value s in the form of ASCII strings separated by periods the number of return values depends on the command given 4 1 Controller operation examples Assuming that all settings are stored in EEPROM issuing the following commands to the PRES HV controller s are sufficient to switch on all powersupplies the auxilary supply no 0 has to be switched on separately and start the measure and adjust process P OEN A P ENA P CTR1 Assuming that all voltage settings stored in EEPROM should be overruled by anew setting of 980V for every HV supply but not for the auxiliary supply of course P OEN A P SV 0980 P ENA P CTR1 Subsequently each HV controller at regular intervals should at least be questioned about the status of its powersupplies P RSS or each controller separately assuming we
11. age of the full DAC range A wildcard for the powersupply address is allowed Command SDc takes as parameter the DA C value to be set 0 63 6 2 10 SVP command P1 2SVP reply p1 2SVP Stores the calibration parameters for the stated powersupply in EEPROM for permanent storage so that they will be used from now on after every power up reset The reply returns the stored values in the same way as described above in the section on command RPA 6 3 Specials 6 3 1 COM command P1ICOM1orP1COMO reply p1 COM lor p1 COM 0 Enables 1 or disables 0 the use of the RTS and CTS handshake lines during RS232 serial output which is necessary in case a socalled COM box is installed to multiplex the serial lines of several HV controllers onto one RS232 line Default the software assumes a COM box is present if this is not the case e g when testing an individual HV controller through a terminal connected directly to the HV controller the first command after a reset should be the COM command otherwise the software will hang up in the serial output High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 7 Error numbers If the reply of the HV controller to a command contains the same command mnemonic it means that the command has been processed correctly If however the reply contains the mnemonic ERR something went wrong The number in the reply following the ERR mnemonic identifies the nature of t
12. ber and the list of mnemonics are only produced when the controller isin spy mode see SPY Supplying a powersupply address is meaningless A controller address wildcard is not allowed High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 1 6 LH X command PILHX lt file_in_IntelH ex_format gt reply p1 LH X 9872 After the command is given the controller will keep on reading lines and interpreting them as Intel H ex formatted lines until a socalled end of data lineis read or if the first chararacter of a line is Q to enable the user to escape from the command when e g a wrong file without an end of data line was downloaded The lines are parsed and written to RAM in binary form the original fileis in ASCII format When the end of data line has been received the EEPROM is programmed which might take several seconds depending on the size of the program Then a reply as shown above is returned in which the number represents the number of bytes of RAM used to temporarily store the code file Supplying a powersupply address is meaningless If an error occurred somewhere in the process the reply will be P1 ERR lt dine no gt lt error_no gt in which dine_no gt is the number of the line in the Intel H ex formatted file which led to the error and lt error_no gt is anumber stating the type of error that occurred See section 7 6 1 7RCA command P12RCA reply p1 2RCA 485 Reads the cu
13. d is 100 yA 6 1 13 RSS command P1RSS reply p1 RSS 0 3 1 0 0 0 0 0 2 0 0 0 0 0 Returns the current on off status of all supplies the first 7 numbers in this reply the auxiliary supply and 6 HV supplies respectively and 7 trip counters one for each supply the counter of the auxiliary supply the first number will always be zero because it is never automat ically switched off Supplying a powersupply address is meaningless Per supply a byte describes whether the supply is switched on or off and if switched off whether there was an abnormal situation that caused it to be switched off where set bits have the following meaning High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 0x01 disabled 0x02 disabled due to measured current load above allowed maximum 0x04 disabled due to measured voltage out of allowed range 0x08 disabled due to set voltage out of allowed range 0x10 disabled due to set voltage out of absolute supply range 0x20 disabled due to on board powerfailure 0x40 error occurred in setting a DAC belonging to this supply 12C bus 0x80 not defined 0x100 error occurred in enabling disabling a supply 12C bus In the example at the beginning of this paragraph the reply shows that all HV supplies and the auxiliary supply are switched on except supply 1 and 2 supply 1 is switched off because ts current load went above its allowed maximum and it tripped
14. e high voltage outputs and the current through this resistor should be measured if any of the other outputs is used a multiplication factor should be applied to the measured current before it is entered in units of 0 1 pA P1G CU 2395 N ow calibration constants e f and g are calculated p1 1GCU 2395 120 342 4370 The same current load calibration procedure is to be followed for all other high voltage supplies 1To be measured at pin 2 of the cascade to microboard connector 2 lowest voltage branch on the box on the left hand side of the HV connector having the COMM connector on the right hand side High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 Now save all parameters in EEPROM P1 0SV P 01 0SV P 8098 715 146 1771 1204 100 300 0 P1 1SVP 01 0SV P 8030 721 147 1756 1201 132 317 3345 P1 2SVP 01 0SV P 8180 725 146 1758 1209 121 376 5460 etc etc 6 Controller commands Below two lists of command mnemonics and their symbolic name are shown the first table contains the commands used during normal operation the second table contains the commands used when the powersupplies are being calibrated in principle commands from this second group are only used once calibration parameters are subsequently stored in the onboard EEPROM and are not expected to change much in time CONTROL_MODE DELETE_EEPROM_ PROGRAM DISABLE_SUPPLY ENABLE_SUPPLY HELP LOAD_INTELHEX READ_CURRENT_ADC REA
15. have eg 3 controllers P1RSS P2RSS P3RSS A full status of one particular powersupply can be requested by for example P2 1RSA High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 5 Calibration of the powersupplies When we calibrate a powersupply we determine the parameters that define the conversion functions between DAC values and Volts between Volts and ADC values and between current loads and ADC value Each of these transfer functions is assumed to be linear which in practice proves to be a valid assumption The voltage V as a function of the coarse setting DAC value D coarse iS V D coarse b The additional voltage V added by the fine setting DAC value D fine iS 2V a Dfine The ADC valueAy as a function of voltage V is Ay cV d and finally ADC value A as a function of current load valuel in units of 0 1 microAmperes and Voltage V is A el fV g In order to be able to calculate parameters a b a c d e f and g itis sufficient to take 2 samples of each transfer function The accuracy of the set high voltage is dependent mainly on the accuracy and stability of the parameters describing the measured ADC value to voltage conversion i e parameters c and d The difference between the measured voltage and the requested voltage is used to adjust the current set voltage independent of what the set voltage actually is according to the DA C value to voltage settings
16. he error Sometimes the ERR reply contains more numbers the error identifier number is always the last number of the reply Below alist of the error identifiers and their symbolic nameis shown EEPROM_TIMEOUT CALIB_VOLT_ZERO CALIB_DAC_ZERO CALIB_ADC_ZERO CALIB_CURRENT_ZERO HEX_CHECKSUM_ ERROR HEX NO CODE HEX_INCOMPLETE HEX TOO BIG 12C_TIMEOUT 12C_STATUS LINE TOO_LONG LINE_INCOMPLETE ERROR_IN_ADDRESS ERROR_IN_PARAMETER PAR_OUT_OF_ RANGE ILLEGAL_CMD UNKNOWN_CMD High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 A description of each error number follows EEPROM_TIMEOUT A timeout occurred on programming data like settings parameters or code bytes of a downloaded program in the EEPROM CALIB_VOLT_ZERO Sensible voltage calibration parameters could not be calculated because there is a zero voltage difference between different calibration steps CALIB_DAC_ZERO Sensible voltage calibration parameters could not be calculated because there is a zero DA C setting difference between different calibration steps CALIB_ADC_ZERO Sensible voltage calibration parameters could not be calculated because thereis a zero ADC reading difference between different calibration steps CALIB_CURRENT_ZERO Sensible calibration parameters could not be calculated because there is a zero current load difference between different calibration steps HEX_CHECKSUM_ERROR A checksum error
17. he example above 75 and 25 respectively There is no need to provide a powersupply address the address provided previously by the CAV command is used 6 2 7 RPA command P1 2RPA reply p1 2RPA 12543 700 543 1277 708 120 300 3200 Reads the currently used values of the calibration parameters that are used in the linear conversions of DAC and ADC units to Volts and Amperes A single powersupply address has to be provided a wildcard is not allowed The numbers contained in the reply are parameters a b a c d e f and g respectively wherea a c e f and g are multiplied by a factor of 1000 0 All these parameters inside the controller program are real numbers but in the reply to RPA they are truncated to an integer In the example above the parameters are thus approximately a 12 543 b 700 0 a 0 543 c 1 277 d 708 0 e 0 120 f 0 300 g 3 200 6 2 8 SDC SDc command P1 2SD C60 reply p1 2SD C 60 High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 Sets the DAC which does the coarse setting for the stated powersupply to the stated value which is a percentage of the full DAC range A wildcard for the powersupply address is allowed Command SD c takes as parameter the DA C value to be set 0 63 6 2 9 SDF SDf command P1 2SD F60 reply p1 2SD F 60 Sets the DAC which does the fine setting for the stated powersupply to the stated value which is a percent
18. hed off The HV controller has to bein calibration mode to be able to perform the commands described in the other sections i e CAC CAD DEP GCU GVO RPA SDC SDF SVP 6 2 3 CAV command P1 2CAV reply p1 2CAV 25 0 Notifies the HV controller that a voltage calibration of a particular supply is to take place The powersupply is enabled and the supply is set to its first calibration setting the two numbers in the reply state what this setting is for the DACs of this powersupply in the example above the coarse setting DAC is set to 25 of its full scale and the fine setting DAC to 0 of its full scale The controller will now expect a total of 4GVO user inputs with voltages in Volts so that it can calculate the DA C to Volts and A DC to Volts parameters after the last GVO input A single powersupply address has to be provided a wildcard is not allowed High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 2 4 DEP command P1 2D EP reply p1 2D EP Deletes the calibration parameters stored in EEPROM for the stated supply after the next reset the default parameters will be used for this supply 6 2 5 GCU command P1GCU2240 reply p1 2G CU 2240 120 300 3500 Tells the HV controller the present current load in units of 0 1 uA The controller will measure the corresponding ADC value and calculate the ADC to current load conversion parameters e f and g these parameters are returned in the
19. igh Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 program e g some testprogram The program is stored in the onboard EEPROM If certain programming rules are obeyed it is possible to switch from one program to the other and back 3 Automatic trip recovery An automatic trip recovery feature has been added to the controller software if the control process is running and a HV supply is switched off by the software a trip because of a value running out of bounds it will be switched on again after a short period of time if a number of consecutive trips occur shortly after one another the HV supply will remain switched off permanently until e g the user switches it on again explicitly The number of consecutive trips that causes the HV supply to be switched off permanently can be set by the user if this number is set to zero or to 1 the controller behaves as if the automatic trip recovery is not enabled The total number of trips during an enabled period for every HV supply is stored by the controller and these trip counters can be inspected by the user After atrip the HV supply is switched on again after 5 sample periods after the supply automatically has been switched on the usual control delay period applies High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 4 Command reply protocol A command to the HV controller has the following syntax lt
20. lution Because of the digital to analog and analog to digital conversions involved each powersupply has been calibrated so that it can be used ina meaningful way the calibration constants are stored in on board EEPROM In normal active operation after the user has started the control and monitoring process the controller takes samples of the current load and voltages of the active powersupplies typically with a rate of 10 Hz witha rate of typically 1 Hz averages are calculated and the voltage is adjusted if necessary and checks are made on the current settings and loads to see if everything still falls within preset safety and control margins if this is not the case for a particular powersupply the supply is switched off this event is recorded in astatusword which the controller keeps for each powersupply The controller also records minimum and maximum values of duty cycles and voltages measured which can be monitored by the user host not for the auxiliary powersupply Therefore the user host should at regular intervals check the status of the powersupplies and take appropriate action whenever a supply is not functioning properly Settings and calibration parameters can be stored permanently in the on board EEPROM so that once stored they are used after every power up reset The software allows for a new program to be downloaded if eg anew version of the software is available but it might also be a totally different H
21. nected to one RS232 serial line hex switches on the controller board can be set to uniquely identify an HV controller an HV controller will only respond to commands addressed to it explicitly or to broadcasted commands commands containing a wildcard address see section 4 an arbitration High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 scheme hardware software prevents more than one controller at a time accessing the serial line for output The on board 80C552 microcontroller controls the powersupply voltages by means of a set of Digital to A nalog converters DAC with 6 bits resolution a high voltage is set combining two DAC outputs a coarse and a fine setting resulting in a resolution close to 12 bits The operating voltage ranges from 800V to 1200V BPC 600V 1000V with a resolution of about 0 15 V The accuracy of the set voltages is within ca 1 V with the control process running and within ca 3 V without The auxiliary supply is also set using two 6 bit DACs and is set at a nominal voltage of about 75 V Each supply has an enable disable input by which the controller switches the supply on or off The voltage and current load of all powersupplies the auxiliary supply and the high voltage supplies are measured using the micro controller s on chip Analog to Digital Converter ADC with a resol ution of 10 bits about 0 4 V of high voltage resolution and about 1 uA of current load reso
22. on the two DACs that explains why the accuracy of the set high voltage depends mainly on the accuracy and stability of parameters c and d N ext follows an example of a complete calibration procedure for a PRES HV controller the command lines to be typed by the user are in bold text type see the chapter on calibration commands for a full explanation of the commands used voltage values and calibration parameters shown are just examples they will be different for each HV controller calibrated High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 Switch to calibration mode PICAL p1 CAL 1 Calibration of the auxiliary supply voltage should be done first it goes in the same way as the calibration of a high voltage supply Calibration of HV supply 1 PLICAV p1 1CAV 10 0 P1G VO 7658 p1 1GVO 7658 90 0 P1G VO 11553 p1 1G6VO 11553 50 0 P1GVO 9576 p1 1GVO 9576 50 100 P1G VO 9662 Now calibration constants a b a c and d are calculated p1 1GVO 9662 8098 715 146 1771 1204 The same voltage calibration procedure is to be followed for all other HV supplies Calibration of a HV supply s current load the first step without any external load the set voltage dependency and offset of the current load are determined factor fV g in the above formula P1 1CAC p1 1CAC 75 10 0 0 90 0 0 50 0 Now the load on the supply should be increased e g by connecting a resistor to the first of the dynod
23. reply as shown above they are multiplied by 1000 and displayed as an integer although inside the program they are reals so the approximate values are e 0 120 f 0 300 g 3 500 Thereis no need to provide a powersupply address the address provided previously by the CAC command is used 6 2 6 GVO command P1GVO 10402 reply p1 2G VO 10402 75 25 or p1 2G V O 10402 12543 700 103 1277 708 Tells the HV controller the current voltage in tenths of a Volts in the example above 1040 2 V The controller will measure the corresp onding ADC value and when this was the last step in the calibration it will calculate the ADC to V olts conversion parameters a b and a and the Volts to A DC conversion parameters c and d after calculating the conversion parameters they are returned in the reply as shown above in the second reply displayed as integers although inside the program they are represented by reals parameters a and a are multiplied by 1000 before High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 they are put in the reply The values in the example above are thus approximately a 12 543 b 700 0 a 0 103 c 1 277 d 708 0 If the GVO command is not the final calibration step the reply will contain apart from the voltage entered by the user the next settings of the coarse and fine setting DAC in percentages of the full DAC ranges of the powersupply being calibrated in t
24. rmation than he needs to know or wants to know The microcontroller sets monitors and controls the voltage and duty cycle of 6 powersupplies each of which will supply high voltage to a number of PMs Additionally it sets and monitors an auxiliary powersupply which supplies the power to the high voltage supplies In the following we will refer to the combination of controller auxiliary supply and the high voltage supplies as H V controller 2 Basic operation The HV controller is connected to the outside world by means of an RS232 serial connection operating at a baudrate of 9600 Through this serial line the HV controller can be controlled and the status of the powersupplies monitored Also the initial calibration of each powersupply is performed under control of the user sitting at a terminal at the other end of the serial line The HV controller behaves like a slave which means it will start performing an action e g switching on a powersupply or reporting about the current status only after receiving a command on the serial line All commands and messages to from the HV controller arein the form of ASCII strings so that it is sufficient to connect a terminal to the RS232 line in order to operate the powersupplies although for regular and continuous monitoring it will be more convenient to connect a hostcomputer to the RS232 line to do the monitoring under software control Itis possibleto have up to 255 HV controllers con
25. rrent value of the current load of a powersupply in ADC units a number between 0 and 1023 if the wildcard is used the reply contains the duty cycle ADC value of all HV powersupplies e g p1 RCA 876 653 485 322 426 376 6 1 8 RCU command P12RCU reply p1 2RCU 256 Reads the current value of the current load of a powersupply and displays it in units of 0 1 UA if the wildcard is used the reply will contain the current loads of all HV powersupplies e g p1 RCU 870 1363 250 345 563 723 High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 1 9 RDC command PIRDC reply p1R D C 423 369 401 345 389 432 Reads the socalled dark current values of all HV powersupplies in ADC units this value is the zero load offset of the current in ADC units for the currently requested high voltage value of each supply This information is of no interest to the common user 6 1 10 RPS command P1RPS reply p1 RPS 11 0 Returns the software version number and whether the code is running from EEPROM 1 or not 0 In the example above the version is 1 1 and the code is not running from EEPROM but EPROM Supplying a powersupply address is meaningless 6 1 11 RSA command P1 2RSA reply p1 2R SA 0 1000 1000 1020 970 1070 560 108 775 345 0 0 Returns current status See RSS set and measured values of one particular powersupply A single powersupply address has to be provided a wildcard is not allowed
26. s gt lt n gt lt m gt lt cmd gt lt par gt lt CR gt with S command tag P for PRES B for BPC n address of the HV controller 0 255 or meaning all HV controllers connected to this RS232 line this command applies to m number of the powersupply on this HV controller the controller the command applies to 0 1 2 or meaning all high voltage powersupplies number 0 is the auxiliary supply and often has to be addressed separatel y if the preceding period and m are not present it is assumed to be cmd three letter command mnemonic par numeric parameter in the form of an ASCII string but only if the command requires a parameter if the command requires a parameter and the parameter is missing it is assumed to be zero A command will always result in a reply unless the HV controller address is not correct or a controller with the specified address is not connected to the serial line every HV controller reads all command lines but will ignore all lines that do not contain its address Lines are interpreted by the HV controller on a line by line basis only after a carriage return lt CR gt has been received the input is interpreted and processed and an acknowledge or error message is returned A reply from the HV controller has the following syntax lt r gt lt n gt lt m gt lt cmd gt lt par1 gt lt par2 gt lt _F gt lt CR gt with r reply tag p for PRES b for BPC n
27. twice and supply 2 is just switched off no abnormal cause 6 1 14 RST command PIRST reply none Causes the controller to be reset by its watchdog timer parameters constants etc are restored to their default or EEPROM stored values If running from EEPROM there will be a switch back to the program in EPROM 6 1 15 RVA command P1 2RVA reply p1 2RVA 485 Reads the current value of the voltage of a powersupply in ADC units a number between 0 and 1023 if the wildcard is used the reply will High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 contain the voltage A DC value of all HV powersupplies e g p1 RD A 876 53 485 567 876 532 6 1 16 RVO command P1 2RVO reply p1 2RVO 1025 Reads the current value of the voltage of a powersupply if the wildcard is used the reply will contain the voltages of all HV powersupplies e g p1 R D U 1023 1024 1021 1023 1024 1020 6 1 17 SCD command P1SCD5 reply p1 SCD 5 Sets the control delay for all HV powersupplies to the requested value The control delay is the delay in seconds taken into account by the control process when the supply is switched on or when the set voltage is changed this in order to let the voltage settle first before starting to regulate it Supplying a powersupply address is meaningless 6 1 18 SCF command P1SCF20 reply p1 SCF 20 Sets the frequency with which averages are calculated for the voltage and du
28. ty cycle of active powersupplies and the frequency with which these quantities are checked and or regulated The required frequency should be multiplied by a factor of 10 In the example above the control frequency is set to 2 Hz Supplying a powersupply address is meaningless the control frequency applies to all HV supplies controlled by this HV controller 6 1 19 SMC command P1SM C1200 reply p1 SM C 1200 Sets the maximum allowed current load of each HV supply in units of 0 1 uA in the above example the value is set at 120 uA High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 1 20 SMT command PISMT2 reply p1 SMT 2 Sets the maximum number of consecutive trips if a HV supply trips again within a certain period of time the supply is disabled and is not switched on again automatically Two trips are called consecutive if at the first control loop after the previous trip the supply trips again Setting the number to 0 or 1 will cause the supply NOT to be switched on automatically after a trip at all 6 1 21 SPY command P1SPY1 or PISPYO reply p1 SPY 1 or p1 SPY 0 Switches the socalled spy mode on or off if the parameter in the command is 1 the spy mode is switched on if it is Othe spy mode is switched off In spy mode the output produced by the HV controller will be a bit more informative This is useful when a user is directly connected to the HV controller with his terminal
29. upply and the HV supplies in Volts and finally the maximum number of trips in a row before a supply remains switched off permanently Supplying a powersupply address is meaningless N ote that the current and the frequencies are multiplied by a factor of 10 In the above example the current is 80 UA and the frequencies are 10 Hz and 1Hz respectively 6 1 25 SWI command P1SWI reply none If avalid program is present in EEPROM or when the present program is running from EEPROM this command will switch to the start of the program in EEPROM or EPROM respectively See also section 8 High Voltage Supply Controller Software PRES BPC User Manual and Reference v1 1 6 2 Commands for calibration 6 2 1 CAC command P1 2CAC reply p1 2C A C 75 10 0 0 90 0 0 50 0 Notifies the HV controller that a current load calibration of a particular supply is to take place The controller will determine the ADC measurement dependency on the set voltage will take a few seconds the reply contains the settings it has used for this procedure and then wait for oneGCU current value user input after which it can calculate the ADC to current load conversion parameters A single powersupply address has to be provided a wildcard is not allowed 6 2 2 CAL command P1CALl1lorP1CALO reply p1 CAL 1or p1 CAL 0 Switches the calibration mode on or off if the parameter in the reply is 1 calibration mode is switched on if it is O calibration mode is switc
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