4A22 USER`S MANUAL
Contents
1. The parameter specification section has the four statements DAVETIMES XX ZAVETIMES XX ZRESETSTEP XX DRESETSTEP XX These token are followed by a single parameter XX The valid parameter range is 1 to 255 These parameters detemine how the 4A22 driver averages its input and zero reference inputs The ZRESETSTEP and ZAVETIMES should not be changed from the values in the example file as these have been found to be optimum The DAVETIMES and DRESETSTEP parameters determine the data averaging operation See the DATA AVERAGING section for more information The next section is the A D startup section This section is used to get initial values of temperature and zero values for auto zero operation These operations will take place only one time when the StartConversions command is given This is so that the first data aquired in the data aquisition loop will be valid Any valid statement can be put in the A D startup section but usually all that is required are the housekeeping statements These are ZEROH ZEROL TEMP These statements need no parameters A ZEROH statement causes the driver to make a zero reading at the high range setting A ZEROL statement causes the driver to make a reading at the low range setting A TEMP statement causes the driver to make a temperature reading The ZEROL and TEMP operations must be done before the 4A22 will return valid data as these values are used in calibration The ZEROH operation is only neccesary if2. 8 Input 10 Input 12 NC Input shield Input common 2 5V reference Input common Input shield NC Input shield PIN on A N 12 14 16 18 20 22 24 26 28 30 32 34 FUNCTION Input shield Input 1 Input 3 Input 5 Input 7 Input shield Input 9 Input 11 Input 13 NC Input shield Input common 2 5V reference Input common Input shield Unreg 6 power Unreg 6 power Note that all analog inputs use Input common as their ground reference not Input shield The input shield connection is intended for use as an input guard only and may be several millivolts away from true input ground Page 7 4A22 USERS MANUAL A D OPERATION GENERAL The 4A22 uses a Maxim MAX132 18 bit integrating A D converter This converter has low power requirements and a serialinterface that make it suitable for the 4A22 s isolated input design Since the maximum conversion rate of the 4A22 is 16 conversions per second and at that conversion rate the overhead of a software calibration routine is minimal a software calibration scheme was chosen to eliminate the need for gain and zero potentiometers Each 4A22 card has a 1K bit serial EEPROM on card that contains calibration constants for that specific card The EEPROM is loaded with these constants during the factory calibration routine These constants are used by the supplied driver software to correct the raw A D output data Zero offset is corrected by sampling a grounded
3. 04 systems The software interrupt uses one of the so called user interrupt vectors from 60H to 6FH The driver attempts to check if the software interrupt is used before installing itself but you should make sure that no other installed software uses the same interrupt vector Once installed all communication to the driver is done via the software interrupt The same calling convention and data record structure is used for all driver functions The driver is accessed by calling its software interrupt with the register pair CX BX CX segment B X offset pointing to the data record Page 10 4A22 USERS MANUAL 4A22 SOFTWARE 4A22DRVR RECORD STRUCTURE To avoid a multiplicity of record structures for 4A22DRVR communication a single record is used It is the responsibility of the calling program to allocate the record structure and provide 4A22DRVR with a pointer to it The calling program must set CX BX to point to the record on entry The record size is 13 bytes total A range value of 0 specifies the low 0 to 0 5V range and a 1 specifies the high range 0 to 5V When status is returned true status is represented by an OFFH byte in the status field and false status by a 00 in the Status field When raw A D data is returned the data is just as read from the converter except that it is sign extended to 32 bits When calibrated data is returned from the A D it is returns as a signed twos complement 32 bit integer expressed as micr
4. 4A22 USER S MANUAL VERSION 1 0 Copyright 1993 by MESA ELECTRONICS Richmond CA Printed in the United States of America All rights reserved This document and the data disclosed herein is not to be reproduced used disclosed in whole or in part to anyone without the written permission of MESA ELECTRONICS Mesa Electronics 4175 Lakeside Drive Suite 100 Richmond CA 94806 1950 Tel 510 223 9272 Fax 510 223 9585 E Mail tech mesanet com Website www mesanet com TABLE OF CONTENTS WARNINGS WARNINGS EE 4 DESCRIPTION GENERA E isto erroe bai rea a duque oan e Rodi nist 5 HARDWARE CONFIGURATION LO ADDRESS e aan nee Geen ade ase Vee ad de RA eae MI EE 7 INPUT CONNECTOR ou ima p Ee nna ER am aa D E ETIANI ME VE ERAT EE A D OPERATION GENERAL alul ao apes d qur RARE Rea ee ae 8 CONVERSION RATE peo res E item kaak 8 CALIBRATION Avena eels bile deine tete p E k ete te a he eode TR e aiu e 9 ACCURACY rahas dd E amaan kad i Me 9 4422 SOFTWARE GENERAD imal aula ae 10 2 ida a AE add vida 10 4A22DRVR RECORD STRUCTURE suit eva een 11 4A22DRVR FUNCTIONS REO UD REIR 11 JA22DRVR RETURN CODES Sis MESI IA went es 15 222 DCE Gr over skin APA EC A medal CHI Voi 14 SEQUENCE FILE PORMA DT oops a Miia eo hem aaa RR ERIT EQ 15 DATAAVERAGING uste stat art a AMA QUE ERAT
5. DCFG After 4A22DRVR is installed it need to be configured in order to set up its operating parameters and background data aquisition loop This is done with the program 4A22DCFG 4A22DCFG loads various user specified parameters and a sequence table into the driver The user parameters and sequence table are in an ASCII text file This file is referered to as a sequence file 4A22DCFG is invoked with the sequence file filename and the 4A22DRVR software interrupt number on the command line 4A22DCFG SEQFILE 60 Would configure the driver using software interrupt 60H with the sequence file SEQFILE SEQUENCE FILE FORMAT The sequence file specified on the 4A22DCFG command line is an ASCII text file consisting of lines terminated with a CR LF Each line starts with a token an ascii name and zero one or two parameters A combination ofa token followed by its parameters is called a statement Lines that start with a semicolon are ignored and can be used for comments The tokens are not case sensitive but are printed here in upper case for emphasis There is an example sequence file SEQFILE in the DRIVER directory of the 4A22 distribution floppy The sequence file has three sections a parameter specification section a A D startup section and a data aquisition loop section The maximum length of the combined A D startup and aquistion loop sections is 128 statements Page 14 4A22 USERS MANUAL 4A22 SOFTWARE SEQUENCE FILE FORMAT
6. ION SCHEMATIC DIAGRAMS Page 25
7. MA VE E 17 ZA22DRDMLE daas edu pue Rhode we dled tates he PER ae eR TERRE UE 19 REFERENCE INFORMATION SPECIFICATIONS ina IRE IMPR DIA Rx M Mp ELLE WARRANTY A veda ecc hx uet ed LCD M TUE SCHEMATICS vedade ad kati ve a e br CE Ha xa ur 4A22 USERS MANUAL WARNINGS HIGH VOLTAGES The 4A22 analog ground is isolated from system ground and can be at dangerous potentials during normal operation DO NOT touch the 4A22 card or the input section shield when operating STATIC ELECTRICITY CMOS integrated circuits on the 4A22 can be damaged by exposure to electrostatic discharges The following precautions should be taken when handling the 4A22 to prevent possible damage A Leave the 4A22 inits antistatic bag until needed B All work should be performed atan antistatic workstation C Ground equipment into which 4A22 will be installed D Ground handling personnel with conductive bracelet through 1 megohm resistor to ground E Avoid wearing synthetic fabrics particularly Nylon Page 4 4A22 USERS MANUAL DESCRIPTION GENERAL The 4A22 is low power integrating 18 bit data acquisition system for the PC 104 bus The 4A22 has 14 input channels with 500V isolation from system ground The analog inputs have software selectable 0 5V or 5V full scale ranges The galvanic isolation of input signals from the computer system ground eliminates ground loop problems common with high
8. OLATED POWER Voltage Load current INPUT CHARACTERISTICS Input current Capacitance to system ground Isolation voltage Common mode dV dT Maximum input voltage ACCURACY Resolution Calibrated accuracy 0 5V range Calibrated accuracy 5V range Uncalibrated accuracy 0 5V range Uncalibrated accuracy 5V range Auto zeroed 0 5V range offset Auto zeroed 5V range offset Calibrated gain TempCo Uncalibrated gain TempCo MIN 4 5 100 100 Page 21 MAX 5 5 75 7 25 2 5 1 50 500 20 6 18 05 05 1 2 20 100 5 100 UNIT NOTES mA Loaded nA at 25 C pF VDC V uSec V bits FSR FSR FSR FSR uV uV PPM C PPM 4A22 USERS MANUAL REFERENCE INFORMATION BUS LOADING Input capacitance 15 pF Input leakage current 3 uA Output drive capability 150 pF Output sink current 8 mA ENVIRONMENTAL Operating temperature range I version 40 85 C C version 0 70 Relative humidity 0 90 Percent Non condensing Page 22 4A22 USERS MANUAL REFERENCE INFORMATION WARRANTY Mesa Electronics warrants the products it manufactures to be free effects in material and workmanship under normal use and service for the period of 2 years from date of purchase This warranty shall not apply to products which have been subject to misuse neglect accident or abnormal conditions of operation In the event of failure of a product covered by this wa
9. and compensates for the total A D gain temperature coefficient The driver allows data acquisition to be done as a background interrupt driven task with the acquired data saved ina driver maintained FIFO The standard FIFO size is 64 entries deep allowing 4 seconds of samples to be acquired without processor intervention other than servicing the interrupt This means that the foreground task can easily poll keyboards do disk I O or other tasks without interfering with the data acquisition sample rate 4A22DRVR The TSR driver is called 4A22DRVR EXE 4A22DRVR is launched with three command line parameters These parameters are the 4A22 base address the hardware interrupt number that the 4A22 will use and the software interrupt number used for communication with the driver For example 4A22DRVR 200 5 60 Would launch the driver with a 4A22 base address of 200H a hardware interrupt number of 5 and a software interrupt number of 60H Note that the base address and software interrupt are specified in hex but the hardware interrupt is specified in decimal as is standard practice with hardware interrupts The base address must match the base address setting of the 4A22 in the system This is the address selected via jumpers W1 W2 and W3 The hardware interrupt must not be used by any other peripheral in the system IRQ 2 and 5 are frequently available in XT PC 104 systems while at least one of IRQ 5 9 10 11 12 and 15 are available in AT PC 1
10. at 4A22 card calibration be done at MESA ACCURACY The 4A22 has a basic accuracy limit of 05 This applies over the full operating temperature range ofthe card This accuracy assumes that the supplied 4A22 driver software is used to calibrate the raw data from the 4A22 s A D chip The main source of inaccuracy is due to mechanical stress on the surface mount reference divider and 10 1 input divider resistors We are changing the 4A22 artwork to use through hole components for these dividers in the next card revision This should improve the basic accuracy to about 02 In order to minimize calibration shifts do to mechanical stress handle the 4A22 gently and try not to twist or flex the card When the 4A22 card is installed in the PC 104 stack press the connectors together by pushing on the female connector not the PC card The 0 5V range is inherently more accurate that the 5V range since the input signal goes directly to the A D converter in this case The temperature channel is mainly for internal use and calibration is only guaranteed to be accurate to 5 C Page 9 4A22 USERS MANUAL 4A22 SOFTWARE GENERAL The 4A22 uses a TSR driver program to access the 4A22 hardware This driver hides may of the details of accessing the 4A22 making the data acquisition application programs task easier The driver uses the EEPROM calibration data to calibrate the A D data does auto zero cycles for both the high and low ranges
11. high range readings need to be made The last section ofthe sequence file is the aquisition loop section This section has the list of A D read operations that the driver will do This list of operations will be sequentially executed and repeated indefinately The aquisition loop section must start with the LOOPSTART statement AII statements in the aquisition loop section cause a A D read operation to take place This means that the total aquisition loop time is 1 16 second times the number of operation in the aquisition loop This fact can be used to assign a time reference to the A D samples Page 15 4A22 USERS MANUAL 4A22 SOFTWARE SEQUENCE FILE FORMAT The following statements can be used in the aquisition loop READ CC RR READAVE CC RR READRAVE CC RR PUSH CC RR PUSHAVE CC RR PUSHRAVE CC RR TOSS CC RR ZEROH ZEROL TEMP CC is a channel number and can has range from 0 to 15 RR is a range specifier and can be either HI or LO READ statements cause the data read from the A D to be stored in a table for later access This access can be asynchronous to the data aquisition loops operation This means that for channels and ranges specified in READ statements the driver can be asked for the data at any time and will return the latest available data for that channel and range READAVE and READRAVE statements have a similar operation but perform data averaging on the aquired data It is the responsibility of the user progra
12. his accumulator is DAVETIMES s larger than the averaged data The accumulator is then scaled by multiplying it by DAVETIMES DAVETIMES 1 The averaged data is then obtained by dividing the accumulator by DAVTIMES The larger the DAVETIMES parameter the smaller the effect new data has on the average The accumulator contents are saved on a per channel basis The total effect of the running average it that of a linear low pass filter The running average is selected by using the PUSHAVE or READAVE statements in the sequence file One disadvantage of the running average is that it may take a very long time to settle after a step change in the input This may be desired if extremely slow time constant filtering is desired but is undesirable for simple noise filtering The resettable averager solves this problem by nonlinear behavior for large input steps The resettable averager operation is basically the same as the running average except that new input data that differs from the average by more than DRESETSTEP counts causes the averager to be reset to the new value New data that is less than DRESETSTEPS different from the current average will simply be averaged in the normal way DRESETSTEP is specified in A D converter counts For A D converter noise filtering a DRESETSTEP of 8 is appropriate The resettable running average is selected by using the PUSHRAVE or READRAVE statements in the sequence file Another use of the resettable average is to establi
13. input channel The zero offset is different on the high and low ranges so zero readings must be taken with both range settings The data from the zero channel is then subtracted from the raw A D data from the other channels The 4A22 has a temperature readout channelthat is used to compensate for the various temperature drifts in the 4A22 circuitry The 4A22 has two input voltage ranges a high range of 5V to 5V and a low range of 0 5V to 0 5V These ranges are software selectable 14 input channels are available for user inputs These are channels 0 through 13 Channel 14 is a temperature readout channel used by the calibration software and channel 15 is the zero reference channel Because of the complexity of the serial interface and sofware calibration scheme it is suggested that the driver always be used to access the 4A22 If you wish to write your own code to access the 4A22 itis suggested that you examine the various 4A22 source files for information on how to access the calibration record etc When the driver software is used calibrated data is presented as a 32 bit integer that represents the input voltage in microvolts CONVERSION RATE The basic conversion rate of the 4A22 is 16 conversions per second This rate is determined by a quartz crystal and is accurate to 200 PPM about 20 seconds a day Because auto zero and temperature readings must be performed in the input scanning loop the throughput of user data is somewhat les
14. m that accesses the driver to only ask for data that has been stored by the aquisition loop All other data is undefined PUSH statements cause A D data channel number and range to be PUSHED onto the data FIFO The data FIFO is a first in first out buffer with each entry consisting of A D data the channel the data came from and the range setting The FIFO size is normally 64 entrys deep The advantage of this FIFO structure is that the time sequence of the A D data is not lost as long as the user program does not let the FIFO overflow Since the maximum A D conversion rate is 16 Hz and the FIFO depth is 64 the user program must only attend to the FIFO about every 4 seconds The PUSHAVE and PUSHRAVE statements are similar to the PUSH statement except that they push averaged data onto the FIFO TOSS statements read the A D and simply discard the data The main use of TOSS statements is to pad the data aquisition loop so that the total time comes out to some desired amount For example a data aquisition loop consisting of one PUSH statement a ZEROL statement a TEMP statement and 13 TOSS statements would have a total length of 16 and therefore a repeat rate of 1 second This means that data would only accumulate in the FIFO at a rate of 1 reading per second Page 16 4A22 USERS MANUAL 4A22 SOFTWARE SEQUENCE FILE FORMAT If the aquisition loop is to run continously you should include a ZEROL and TEMP token in the loop You should als
15. o include a ZEROH token if you use the high range The time spent on these housekeeping chores can be minimized by interleaving them with the normal data aquisition steps For example if your aquisition loop needs to PUSH 4 channels of data the aquisition loop section could contain the following sequence PUSH 1 HI PUSH 4 LO PUSH 8 LO PUSH 7 HI TEMP PUSH 1 HI PUSH 4 LO PUSH 8 LO PUSH 7 HI ZEROL PUSH 1 HI PUSH 4 LO PUSH 8 LO PUSH 7 HI ZEROH This would keep the overhead of the housekeeping chores to 1 5 of the readings This technique can also be used to mix frequently read channels with channels that are only read occasionally The only limitation is that the total sequence length must be 128 statements or less This includes any A D startup statements DATA AVERAGING Data read from the 4A22 A D can optionally be averaged by the 4A22DRVR software Averaging can be used for noise filtering or where it is desired to low pass filter the input signal Two types of averaging are available running average and resetable running average The running average is useful for low pass filtering of the input signal Its operation is determined by the input signal sampling rate as determined by the aquisition loop and the DAVETIMES parameter Page 17 4A22 USERS MANUAL 4A22 SOFTWARE DATA AVERAGING The running averager works as follows Every time an averaged channel is read or pushed the A D data is summed to an accumulator T
16. ovolts The record structure is as follows DATA DATA SIZE BYTE OFFSET Function number byte 0 Return code byte Status byte 2 Pointer offset word 16 bits 3 Pointer segment word 16 bits 5 Data longint 32 bits 7 Channel byte 11 Range byte 12 4A22DRVR FUNCTIONS These are determined by the function number in the Function number field ofthe data record The following is a list and brief description of the driver functions For more information on the 4A22DRVR functions you should refer to the 4A22DRVR source code in the SOURCE directory of the 4A22 distribution floppy Applicable files are 4A22DRVR PAS 4A22LOW PAS and 4A22DFUN PAS Page 11 4A22 USERS MANUAL 4A22 SOFTWARE 4A22DRVR FUNCTIONS FUNCTION NUMBER DrFuncGetVersion 0 Returns Version in Data field DrFuncGetConvStatus 1 Returns converter running status is Status field running true stopped false DrFuncGetDriverStatus 2 Return configuration status of driver is Status field true configured false not configured DrFuncGetFIFODataStatus 3 Return FIFO data available status in Status field true data available false FIFO empty DrFuncGetFIFOOvflStatus 4 Return FIFO overflow status in Status field true FIFO has overflowed false no overflow Overflow status can be cleared by stopping the conversions and then restarting them DrFuncStartConversions 5 Start background data conversions DrFuncStopConversions 6 Stop backg
17. resolution A D converters and allows floating measurements to be made The 4A22 requires on 5V power Total power supply current is less than 50 mA A small amount 6V and 6V 2 5 mA max of isolated power is available at the analog input connector for powering isolated signal conditioning circuits There are different 4A22 models for optimum 50 and 60 Hz power line rejection The conversion rate of the 4A22 is 16 conversions per second 60 Hz model and 13 33 conversions per second 50 Hz model The 4A22 can be programmed to generate an interrupt when it has completed a conversion allowing background data acquisition The 4A22 can use any of the AT bus interrupts The IRQ line selection is software programmable no interrupt jumpers 4A22 calibration data is stored in an on card EEPROM so no zero or full scale adjustment potentiometers are needed In fact calibration requires no access to the 4A22 card itself An on card temperature readout channel allows the driver software to compensate for the 4A22 s temperature coefficients Driver software for background data collection is supplied with the 4A22 This driver acquires data in the background on an interrupt driven basis scales and auto zeros the data and stores the processed data in an application program readable FIFO The channel and range sequence that the background task acquires is programmable via a simple ASCII file Source code for the driver program and example interfacing p
18. rograms is supplied with the 4A22 Page 5 4A22 USERS MANUAL HARDWARE CONFIGURATION I O ADDRESS The only user settable hardware option on the 4A22 card is the base I O location The 4A22 card uses 8 contiguous addresses in I O space The 4A22 base address has seven optional locations These are set with jumpers W1 W2 and W3 Jumper blocks W1 W2 and W3 are three pin headers with two valid jumper positions up and down Up means away from the J1 and J2 bus connectors The following table shows the 4A 22 base addresses for different jumper settings BASE ADDRESS wi W2 W3 0200H down down down 0208H down down up 0210H down up down 0218H down up up 0220H up down down 0228H up down up 0238H up up down DISABLED up up up The all up position completely disables the 4A22 card and can be used when checking for I O conflicts This set of base addresses is determined by PAL U17 and can be changed if neccesary Contact MESA if you require a different set of I O base addresses Page 6 4A22 USERS MANUAL HARDWARE CONFIGURATION 10 CONNECTOR The 4A22 uses a 34 pin right angle male header for its analog input connector The suggested mating connector is AMP PN 746194 9 This is an IDC flat cable type connector The analog input connector pinout is as follows PIN m ON nN WO m 1 13 15 17 19 21 23 25 27 29 31 33 FUNCTION Input shield Input 0 Input 2 Input 4 Input 6 Input shield Input
19. round data conversions Also clears FIFO FIFO overflow status and scan count Page 12 4A22 USERS MANUAL 4A22 SOFTWARE 4A22DRVR FUNCTIONS FUNCTION NUMBER DrFuncGetCalData 7 Returns calibrated data in Data field enter with channel number in Channel field and range in Range field DrFuncGetRawData 8 Returns low range raw data in Data field enter with channel number in Channel field and range in Range field DrFuncGetTemperature 9 Returns low range zero reading in Data field DrFuncGetZero 10 Returns zero reading in Data field enter with range in Range field DrFuncGetFIFOData 11 Returns FIFO data FIFO channel and FIFO range in Data Channel and Range fields DrFuncGetScanCount 12 Returns the current scan count number of times around the data aquisition loop in the Data field DrFuncGetAtoDRecPtr 13 Return pointer to AtoD Record in Pointer segment and Pointer offset fields DrFuncGetCalibRecPtr 14 Return pointer to Calibrate Record Pointer segment and Pointer offset fields Page 13 4A22 USERS MANUAL 4422 SOFTWARE 4A22DRVR RETURN CODES The return code field of the Interrupt record indicates whether or not the function was successful or ifthe function failed why Return codes are as follows RETURN CODE MEANING 00 Successful completion 01 Failed 02 Bad parameter Failed usually means an unimplemented function Bad parameter means that the channel or range number is not valid 4A22
20. rranty Mesa Electronics will repair any product returned to Mesa Electronics within 2 years of original purchase provided the warrantor s examination discloses to its satisfaction that the product was defective The warrantor may at its option replace the product in lieu of repair With regard to any product returned within 2 years of purchase said repairs or replacement will be made without charge If the failure has been caused by misuse neglect accident or abnormal conditions of operation repairs will be billed at a nominal cost THE FOREGOING WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESS OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTY OF MERCHANTABILITY FITNESS OR ADEQUACY FOR ANY PARTICULAR PURPOSE OR USE MESA ELECTRONICS SHALL NOT BE LIABLE FOR ANY SPECIAL INCIDENTAL OR CONSEQUENTIAL DAMAGES WHETHER IN CONTRACT TORT OR OTHERWISE If any failure occurs the following steps should be taken 1 Notify Mesa Electronics giving full details of the difficulty On receipt of this information service data or shipping instructions will be forwarded to you 2 On receipt of the shipping instructions forward the product in its original protective packaging transportation prepaid to Mesa Electronics Repairs will be made at Mesa Electronics and the product returned transportation prepaid Page 23 4A22 USERS MANUAL REFERENCE INFORMATION Page 24 4A22 USERS MANUAL REFERENCE INFORMAT
21. s For example an input scanning loop might read the 13 user inputs do a high range auto zero operation a low range auto zero operation a temperature reading and then repeat This loop would take one second and read 13 user channels It is possible to improve the throughput by interleaving the housekeeping chores See the 4A22 SOFTWARE section for an example ofinterleaving the housekeeping Page 8 4A22 USERS MANUAL A D OPERATION CALIBRATION The 4A22 is calibrated at MESA but can be re calibrated if necessary To do a voltage only calibration requires that reference voltages of 4V and 4V are available The reference voltage source should be accurate to 50 PPM or better A complete calibration requires a temperature controlled oven in order measure the gain temperature coefficients and calibrate the temperature channel It is suggested the original temperature coefficient data be used unless there is a compelling reason to change it Calibration is performed via the program 4A22CAL EXE 4A22CAL is invoked with the hexadecimal port address ofthe 4A22 plus the optional T parameter if a temperature calibration is to be performed 4A22CAL 200 T 4A22CAL prompts you to connect different voltages to the input channel When 4A22CAL is done it will write the new calibration data into the 4A22 s EEPROM If the T option is specified 4A22CAL will do a temperature only calibration We do supply 4A22CAL to the user but strongly suggest th
22. sh initial conditions for the running averager Both averagers share the same data accumulators so by using the resettable average in the A D startup section of the sequence file the averager will be preset to the first reading from the A D Page 18 4A22 USERS MANUAL 4A22 SOFTWARE 4A22DRDM 4A22DRDM is a simple demonstration program of the 4422 card amp 4A22DRVR combination 4A22DRDM reads data from the drivers FIFO and displays it on the screen 4A22DRDM determines where to display the data by its channel number read from the FIFO 4A22DRDM is launched with the software interrupt number of the driver on the command line 4A22DRDM 60 Would launch the demo program and have the program use software interrupt 60H to communicate with the 4A22DRVR program Assuming that 4A22DRVR is not already loaded the full sequence of commands needed to run 4A22DRDM would be as follows 4A22DRVR 200 5 60 4A22DCFG SEQFILE 60 4A22DRDM 60 The assumptions here being that the 4A22 is located at the default 200H base I O location that IRQ 5 is free and unencumbered and that software interrupt 60H is free The sequence file SEQFILE would of course have to contain some PUSH PUSHAVE or PUSHRAVE statements in its aquisition loop section for 4A22DRDM to display anything Page 19 4A22 USERS MANUAL Page 20 4A22 USERS MANUAL REFERENCE INFORMATION SPECIFICATIONS POWER SUPPLY Voltage Supply current no external load IS
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