Home

A1216E Manual - ACCES I/O Products, Inc.

1. Multiplying by 16 shifts the A D channel number into the upper nibble The upper byte of the parameter CHANNEL is reserved for future expansion and must be set to zero in current programs SETGAIN unsigned int BASE_ADDRESS unsigned int GAIN This routine outputs the desired A D and sub multiplexer gain The A D gain is stored in the upper nibble of the low order byte and the sub multiplexer gain is stored in the lower nibble of the same byte The high order byte is reserved for future expansion and should be set to zero On some A D cards it s not possible to set the gain without also setting the channel To avoid changing the channel when only the gain is meant to change the current channel is stored in an external variable CURCH The contents of this variable are combined 1f required with the desired gain to produce the actual command byte s The contents of CURCH depend upon SETCHANNEL being used to set the channel If SETCHANNEL is not used your program must set CURCH directly prior to calling SETGAIN unsigned integer CARDEXISTS unsigned int BASE_ADDRESS Return non zero TRUE if it detects the A D card at BASE_ADDRESS unsigned integer TESTCARD unsigned int BASE_ADDRESS Return non zero if A D card appears to perform A D conversion properly Manual MA1216E D2a Page 4 3 A1216E Manual Page 4 4 integer COUNTERMODE unsigned int BASE_ADDRESS unsigned int COUNTER unsigned int MODE This routine programs the mode of
2. Digital output 3 N 2 Common Logic ground 18 LLOND Analog Common LL GND Analog Common 20 LL GND Analog Common 10 Unused 1 Outp bannel 0 2 analos Q R ela la o o lo ln NIN N N iu IS jO Jn JB fu tn J jS un o lu Io GO JL fu Ju JOO Uy Un IND IS Page B 4 Manual MA1216E D2a Appendix C Basic Integer Variable Storage Data are stored in integer variables type in 2 s complement form Each integer variable uses 16 bits or two bytes of memory Sixteen bits of binary data is equivalent to O to 65 535 decimal but the 2 s complement convention interprets the most significant bit as the sign bit so the actual range is 32 768 to 32 767 Numbers are represented as follows High Bye O __ ooo F fofi fi fo fo fo i fi T fo fo fo fo 32768 li To To o To To Jo o To o To o lo To To To Note Bit 7 B7 of the high byte is the sign bit 1 negative O positive Integer variables are the most compact form of storage for the 12 bit data from the A D converter and the 16 bit data from the interval timer Therefore to conserve memory and disk space and to optimize execution time all data exchange via the CALL is through integer type variables This poses a programming problem when handling unsigned numbers in the range 32 768 to 65 535 If you wish to input or output an unsigned integer greater than 32 767 then 1t is necessary to work out what its 2 s complement signed equivalent is For
3. 0 may be driven by the internal 1MHz clock or by an external clock source Base C Write Read Counter 0 read or write When writing this register is used to load a counter value into the counter The transfer is either a single or double byte transfer depending on the control byte written to the counter control register at Base F If a double byte transfer is used then the least significant byte of the 16 bit value is written first followed by the most significant byte When reading the current count of the counter is read The type of transfer is also set by the control byte Additional information about the type 8254 counters is presented in the Programmable Interval Timer section of this manual However for a full description of features of this extremely versatile IC refer to the Intel 8254 data sheet The counter read write registers are located as follows Base D Write Read Counter 1 read or write See description for Base C Base E Write Read Counter 2 read or write See description for Base C Base F Write The counters are programmed by writing a control byte into a counter control register at Base Address F The control byte specifies the counter to be programmed the counter mode the type of read write operation and the modulus The control byte format is as follows TT Is Ta Ta Ta Tar Tm SC0 SC1 These bits select the counter that the control type is destined for lo 0 Program Counter 0__
4. Appendix C Basic Integer Variable Storage ooooooooommoo m C 1 Appendix D PPI Data Sheets 2 000 eee D 1 Page vi List of Figures Figure 1 1 A1216E Block Diagram a id ar 1 6 Figure 3 1 A1216E Option Selection Map kk kk kK KK KK KK KK KK KK KK KK KK nenn 3 3 List of Tables Table 3 1 Standard Address Assignments For 286 386 486 Computers 3 6 Table 3 2 Base Address Example Jk A kk kk kk KK kK KK KK KK KK KIRR KI KK KI KK KK nenn 3 7 Table 6 1 A1216E Register Address Map kk kk kK KK KK KK KK K KI eee 6 1 Table B 1 A1216E Primary Connector Pin Assignments XL KK RR KK KK KK B 1 B 2 Table B 2 A1216E Auxiliary Connector Pin Assignments 00000 eee Page vii Page viii Chapter 1 Introduction The A1216E is a multifunction high speed analog digital I O card for use in IBM Personal Computers It is a 3 4 length card that can be installed in an expansion slot of IBM PC XT AT and compatible computers With this card installed the computer can be used as a precision data acquisition and control system or as a signal analysis instrument The following paragraphs describe functions provided by this card Analog Inputs The card accepts up to eight differential or 16 single ended analog input channels Inputs are protected against overvoltage by the internal multiplexer diodes rated at 20mA maximum connected to the and terminals of the power supply An external series 1KQ resis
5. This function should be the first function called before any other MDM function This function due to the nature of mixed language programming stores the address in an external variable called BADDR That variable can not be used from your application program It is defined and maintained by the include files provided with the MDM for each language int GETDATA unsigned integer FirstChannel unsigned integer LastChannel unsigned integer pointer Buffer This routine takes buffered data from the sub multiplexer card from first channel to last channel and stores the data in the array Buffer The Buffer must be large enough to contain lastChannel FirstChannel 1 elements of two byte unsigned integer data This routine performs very little error checking and is designed as a primitive function to acquire data as fast as possible using programmed VO The above are the only functions common to all Multiplexer Driver Modules Although it s possible to program for any multiplexer using just these functions doing so negates any advanced features of the multiplexer such as channel by channel gain programming anti alias filtering simultaneous sample and hold etc Therefore each MDM contains multiplexer specific functions to simplify use of the full feature set for its sub multiplexer card Page 4 6 Manual MA1216E D2a Using the MDM Driver The most common method to use the MDM driver is to begin a program as usual call SetBaseAddress with the addr
6. a K You will need to swap disks as requested by the system In a two disk system the command is diskcopy a b K This will copy the contents of the master disk in drive A to the backup disk in drive B Manual MA1216E D2a Page 2 1 A1216E Manual To copy the files on the master diskette to your hard disk perform the following steps a Place the master diskette into a floppy drive b Change the active drive to the drive that has the diskette installed For example 1f the diskette is in drive A type a K ds Type installK and follow the on screen prompts Directories Created on the Hard Disk The installation process will create several directories on your hard disk If you accept the installation defaults the following structure will exist CARDNAME Root or base directory containing the SETUP EXE setup program used to help you configure jumpers and calibrate the card DOS PSAMPLES A subdirectory of CARDNAME that contains Pascal samples DOS CSAMPLES A subdirectory of CARDNAME that contains C samples Win32 language Subdirectories containing samples for Win95 98 and NT WinRisc exe A Windows dumb terminal type communication program designed for RS422 485 operation Used primarily with Remote Data Acquisition Pods and our RS422 485 serial communication product line Can be used to say hello to an installed modem ACCES32 This directory contains the Windows 95 98 NT driver used to provide access to the hardwar
7. connected to output drivers capable of providing 3 mA current drive By setting on board switches you can select outputs of 0 3 VDC 0 10 VDC 0 2 5 VDC 2 5 VDC 5VDC or 10 VDC Page 1 2 Manual MA1216E D2a Interrupts Interrupts can be initiated either by completion of an A D conversion or by counter timeout if programmed by software Interrupt levels 2 through 7 10 through 12 14 and 15 are selectable via jumpers Reference Voltage and Power Requirements A 45 0 volt 0 05 V reference voltage is produced internally for the A D converter and the D A analog outputs The A1216E requires only 5VDC from the computer power supply An on board DC DC converter translates the 5 VDC to low noise isolated 15VDC for the precision analog circuitry Input Output Connections External connections are made through a standard 37 pin male D connector located at the rear of the computer and an auxiliary 40 pin IDC connector on the board External multiplexers or signal conditioning hardware such as our AIM 16P or LVDT 8 are connected using special cabling as described in APPENDIX B Utility Software Utility software is provided with the A1216E card This software includes an illustrated setup and calibration program and a universal software driver for any language that supports the Pascal calling convention such as QuickBASIC C and Pascal and sample programs Specifications Analog Inputs e Channels Switch selectable 8 dif
8. program Most modern languages allow you to perform the compile and link steps together from within an editor shell or development environment In C this requires proper creation of a Project or Make file In contrast the Pascal language allows the link steps and hierarchial source relationships to be specified from within the source files eliminating any need for a Project file Procedures specific to any given language can be found in documentation provided with the language Typically this is in a section titled Using Multiple Source Modules Linking or Interfacing to Other Languages Please consult that documentation for further details if necessary Programming with the CDM Driver The most common method of programming with the CDM will be to create a program as usual call GETADDATA to acquire data from the card manipulate and or display the data and repeat the process as usual Alternatively one of the other GETADxxxDATA routines can be used to satisfy specific needs If a program needs lower level control of the data acquisition process typical code might look like the following outline CARDEXISTS if not end SETCHANNEL SETGAIN STARTCONVERSION CHECKFOREOC If not EOC repeat the check RETRIEVEANALOGCONVERSION Repeat at SETCHANNEL as many times as desired Manual MA1216E D2a Page 4 5 A1216E Manual Multiplexer Driver Module MDM Each Multiplexer Driver Module provides routines to access a specific sub mul
9. 1MHz clock low selects external clock input to connecter pin 21 CTRO IN ADCO When high Analog Digital conversion starts upon Counter 2 timeout ADC1 When high Start ADC conversion with external trigger pin 25 TRIG 0 ADC2 When high Generate an IRQ upon ADC end of conversion IT2 When high Generate an IRQ when Counter 2 times out Note Counter 2 must be in mode 2 to produce interrupts CHGCHV When set high Enable ADC conversion start upon a read to Base 4 When set low Enable ADC start upon any write to Base 2 CHGCHV must be high to enable hardware start conversions IRQ The returned bit is reserved for future use GATE1 Gate input to Counter 1 to enable counting set high to enable gate GATE2 Gate input to Counter 2 to enable counting set high to enable gate Enable GATE1 and GATE2 together when cascading counters Page 6 2 Manual MA1216E D2a Base 2 Read and Write ADC Command and Status Register Start ADC Conversion with any write operations if CHGCHV of Base 0 is low BEREIT aa TEN A BUSY SE BAL GAINI GAINO MA3 MA2 MAI MAO MAO Least Significant Bit LSB of ADC Analog Channel Select multiplexer MAI Second Significant Bit of ADC Analog Channel Select multiplexer MA2 Third Significant Bit of ADC Analog Channel Select multiplexer MA3 Most Significant Bit MSB of ADC Analog Channel Select multiplexer For example 0000 is A D Channel 0 1111 is A D Channel 15 GAINO 1 GAIN1 GAINO Pre Conve
10. BUFFER REGISTER N INTERRURI RESA qi JUMPERS PORT Ao _ LJ PORT BT 8255 CTRO CTRO CTR2 PORT C 9 CLOCK OUT OUT IN Figure 1 1 A1216E Block Diagram Page 1 6 Manual MA1216E D2a NEW QU SU Chapter 2 Installation The software provided with this card is contained on either one CD or multiple diskettes and must be installed onto your hard disk prior to use To do this perform the following steps as appropriate for your software format and operating system Substitute the appropriate drive letter for your CD ROM or disk drive where you see d or a respectively in the examples below CD Installation DOS WIN3 x 1 Place the CD into your CD ROM drive 2 Type d K to change the active drive to the CD ROM drive 3 Type installK to run the install program 4 Follow the on screen prompts to install the software for this card WIN95 98 NT a Place the CD into your CD ROM drive b The CD should automatically run the install program after 30 seconds If the install program does not run click START RUN and type d install click OK or press K Follow the on screen prompts to install the software for this card 3 5 Inch Diskette Installation As with any software package you should make backup copies for everyday use and store your original master diskettes in a safe location The easiest way to make a backup copy is to use the DOS DISKCOPY utility In a single drive system the command is diskcopy a
11. KK KK KK kk kk kk Ke 7 2 Input Range and Resolution Specifications 0 000 cee KK KK 7 2 Current Measurements tail ES kK KK KK KK KK KK KK KK AS 7 3 Measuring Large Voltages mios co kK KK KK kK KK KK KK KK KI KK KK KK KK KK KK KK kk 7 3 Chapter 8 Programmable Interval Timer ss KK RR RR RR RR RR KK KK SS 8 1 Operational Modes o KK KK KK KK KK KK KK KK KK KK KK KK kK KK KK kk 8 1 Programming gt sa 3 xa 44222 d 4 iaae d re dt dev dade ew dle Qewl Ad e des 8 2 Reading and Loading the Counters kk kk KK KK KK KK KK KK KK KK KK KI KK KK KK nn 8 4 Programming ExXamples u xali ner ee ee 8 5 Generating Time Delays A a KK KK KK KK KK KK KK KI KK KK KK KK KK KK KK kk 8 6 Generating Interrupts with the Counter Timer kk kk kk kk KK KK RR RR RR KI KIRI KI KI 8 7 Chapter 9 D A ConverterS Jk kk kk kk kk kk kk kk kk kk kk kk kk kk kk kk kk kk kk 9 1 Programming se 2s da kicked O ka d k e lh a E a a hea d Bi arek a A j duh ore 9 1 Appendix A Linearization kk kk kk kk KK KK KK KK KK KK kk kk kk kk kk kk A 1 Appendix B Cabling and Connector Information B 1 A1216E Primary Connector Pin Assignments 0000 00 KK KK B 1 A1216E Auxiliary Connector Pin Assignments 22222 KK eee KK KK B 2 A1216E to First Multiplexer Set Cable Adapter Assembly 22222220 B 3 A1216E to Additional Multiplexers Cable Adapter Assembly 22 05 B 4
12. This last is of the most general use and is selected for each counter by setting the RW1 and RWO bits to ones Of course subsequent read load Operations must be performed in pairs in this sequence or the sequencing flip flop in the 8254 chip will get out of step Base F Read Counter Control Byte CNT When is 0 latches the counters selected by bits CO C2 STA When is 0 returns the status byte of counters selected by CO C2 CO Cl C2 When high select a particular counter for readback CO selects Counter 0 C1 selects Counter 1 and C2 selects Counter 2 Page 8 4 Manual MA1216E D2a You can perform two types of operations with the Counter Control Byte When CNT 0 the counters selected by CO through C2 are latched simultaneously When STA 0 the counter status byte is read when the counter I O location is accessed The counter status byte provides information about the current output state of the selected counter and its configuration The status byte returned if STA 0 is OUT Current state of counter output pin NC Null count This indicates when the last count loaded into the counter register has actually been loaded into the counter itself The exact time of load depends on the configuration selected Until the count is loaded into the counter itself it cannot be read RW1 amp RWO Read Write command M2 M1 MO Counter mode BCD BCD 0 is binary mode otherwise counter is in BCD mode If both STA and CNT bits i
13. a given counter without loading a value This has the effect of turning the counter OFF and the counter will no longer count down change output value etc This routine can be used to treat the counter as a digital output bit by setting mode 0 or mode 1 to set the output of the counter either low or high respectively This can be highly useful for debugging programs with otherwise complicated timing integer PROGRAMCOUNTER unsigned int BASE_ADDRESS unsigned int COUNTER unsigned int MODE unsigned int LOADVALUE This routine programs the type 8253 or 8254 counter on the A D card with the mode and load value specified on the desired counter number COUNTER must be a valid counter number for the card in question typically 0 1 or 2 See the Error List for a description of errors int GETADDATA unsigned int BASE_ADDRESS unsigned int FIRSTCH unsigned int LASTCH unsigned int SCANS unsigned int pointer BUFFER This routine acquires data from the A D card as quickly as possible using programmed I O It repeats this data acquisition as many times as programmed by SCANS on the channels delimited by FIRSTCH and LASTCH It s possible to acquire a single channel by setting FIRSTCH and LASTCH to the same channel number The data resulting from this routine is stored in BUFFER That pointer must point to an array of sufficient size to contain all of the data This routine will generate LASTCH FIRSTCH 1 SCANS elements of unsigned integer data Se
14. a maximum conversion rate of 100 000 conversions per second 2 independent 12 bit double buffered Offset binary or two s complement by jumper selection 0 9 LBS maximum bit 0 2 5V 0 5V 0 10V 2 5V 5V 10V 5 mA minimum 0 5 O 15 usec to Ya LBS 2 0 to 5 0 VDC at 20 WA maximum at 2 7V 0 5 to 0 8 VDC at 0 4mA maximum 2 4V minimum at 2 6 mA source 0 5V maximum at 24 0 mA sink Manual MA1216E D2a e 24 Bits on Auxiliary 40 Pin D Connector Inputs Logic high 2 0 to 5 0 VDC at 10 WA maximum Logic low 0 5 to 0 8 VDC at 10WA maximum Outputs Logic high 2 5V minimum at 200HA source Logic low 0 5V maximum at 1 7mA sink Interrupt Channel e Levels Levels 2 through 7 and 10 12 14 and 15 jumper selectable e Enable The two IRQ sources End of Conversion CTR2 timeout are individually enabled via control bits in the BASE 0 control register Reading the control register clears the IRQ latch and prepares the card to generate the next IRQ Programmable Timer e Type 82C54 2 programmable interval timer e Counters Three 16 bit down counters two permanently concatenated as a pacing counter with a 1MHz clock One is uncommitted and driven by the IMHz clock or an external clock source e Output Drive 2 2mA at 0 45V 5 LSTTL loads e Input Gate TTL DTL CMOS compatible e Clock Frequency DC to 10MHz e Active Count Edge Negative edge e Min Clock Pulse Width 30nS high 50nS low
15. e Timer Range 2 5 MHz to lt 1 pulse hr Environmental e Operating Temp 0 C to 50 C e Storage Temp 20 C to 70 C e Humidity 0 to 90 RH non condensing e Weight 10 oz e Power Required 5VDC 800 mA typical Manual MA1216E D2a Page 1 5 A1216E Manual UNI BIP UNIPOLAR BIPOLAR X1 X2 x1 x2 JUMPER 16 S E 8 DIFFL SWITCH A 2 CHO HIo 12 BIT_A D CONVERTER CHO Lo 2 WITH SAMPLE AND HOLD GAIN AD amp MUX T SEE SELECT 8 DIFFL MUX DATA REGISTER ANALOG INPUTS 15V DC DC 45V STATUS 15v 4 CONVERTER REGISTER CH15 L e MUX INCREMENT amp CONTROL LOGIC D A 0 DATA e 49 BIT DIA INTERNAL DATA BUS tae singe TRIGGER 12 BIT DAK een Rs LOGIC EE ADDRESS D TRI aa 4 e DECODE AD RIG TIMER ENABLE Tc amp REGISTER Es 7 SELECT IPQ o 8 Pio 4BIT IP2 t INPUT REGISTER Da GATE GATE e CONTROL gt REGISTER N CTRO GATE x s4 lt BIT BIT QPQ0o TRISTATE 4 BIT CTR CTR CTR AR OUTPUT 1 OP2
16. gain to x1 Calibration Potentiometers DAC Analog Output ADC Analog Input RP1 DACO Zero Adj RP5 Output Offset RP2 DACO Span Adj RP6 Fullscale Adjust RP3 DAC1 Zero Adj RP7 Input Offset RP4 DAC1 Span Adj RP8 Unipolar Offset Counter Timer Three 16 bit Counter Timers are provided on A1216E Refer to the block diagram for an understanding of the counter timer configuration and to the Programmable Interval Timer section for programming and applications Counters 1 and 2 are intended for software programmed timed A D start Counter 0 has its clock and output lines available on the I O connector for general purpose use The gate input for Counter 0 is at digital input IP2 Clock Frequency Select The clock for Counter 0 and 1 is a 1 MHz clock derived from an on board crystal oscillator Counter 0 may also select an external clock input under software control see the Software chapter for the register address Page 3 4 Manual MA1216E D2a Selecting and Setting the Base Address The following section shows you how to select and set the address Selecting a Base Address You need to select an unused segment of 20 consecutive I O bus addresses The base address will be the first address in this segment The base address may be selected anywhere on a 32 bit boundary within the I O address range 100 3FF hex providing that it does not overlap with other functions The following procedure will show you how to select the base I O a
17. into the counter When triggered the counter output goes low for one clock period after N counts reloads the initial count and the cycle starts over This mode is periodic the same sequence is repeated indefinitely until the gate input is brought low This mode is used on the A1216E card in Counters 1 and 2 to generate periodic A D start commands This mode also works well as an alternative to mode O for event counting Mode 3 Square Wave Generator This mode operates periodically like mode 2 The output is high for half of the count and low for the other half If the count is even then the output is a symmetrical square wave If the count is odd then the output is high for N 1 2 counts and low for N 1 2 counts Periodic triggering or frequency synthesis are two possible applications for this mode Note that in this mode to achieve the square wave the counter decrements by two for the total loaded count then reloads and decrements by two for the second part of the wave form Mode 4 Software Triggered Strobe This mode sets the output high and when the count is loaded the counter begins to count down When the counter reaches zero the output will go low for one input period The counter must be reloaded to repeat the cycle A low gate input will inhibit the counter This mode can be used to provide a delayed software trigger for initiating A D conversions Mode 5 Hardware Triggered Strobe In this mode the counter will start countin
18. register accesses such programming is time consuming can involve a steep learning curve and can result in lengthy debugging Software drivers are provided with the card s to ease the burden of programming data acquisition systems These drivers provide an additional function as well They buffer the application program so that it s not necessary to program specifics about the A D card In many ways it s possible to write a single application source code that s usable with any supported A D card Our driver software that allows this feat is called the Card Driver Module or CDM Also to support sub multiplexers such as the AIM 16 or LVDT 8 a second driver module known as a Multiplexer Driver Module or MDM is provided with the sub multiplexer card Routines in the MDM are specific to the nature of the sub multiplexer supported but a common functionality is transparently supported by all MDMs This allows the simplest application of a sub multiplexer multiplexing A D channels to provide additional channels to be written identically regardless of the sub multiplexer in use Together these two driver module types CDM and MDM provide simple and portable access to both the A D cards and the attached sub multiplexers This section of the manual gives detailed information about the CDMs provided and the A1216E CDM Note For most programs no knowledge of the MDM specification is required If the only data you intend to acquire is from the A
19. to program the A1216E using the direct register access At the lowest level the A1216E can be programmed using direct I O input and output instructions Use of these functions usually involves formatting data and dealing with absolute I O addresses Although not demanding this can require many lines of code and requires an understanding of the devices data format and architecture of the A1216E A1216E Register Address Map The A1216E uses 20 consecutive addresses in I O space as follows Register Address Hex Read Function BASE ADDRESS 0 Read Status Register Write Command Register BASE ADDRESS 1 Read Digital In and clear IRQ latch Digital Out amp Tristate control ADC Command amp Status BASE ADDRESS 2 Read ADC Status Start ADC Conversion if CHGCHV low Not Used Not Used Not Used Load LSB DAC 0 BASE ADDRESS B Not Used Load hee Update DAC 1 Clear Zero BASE ADDRESS 12 Read Aux 8255 Port C Input Aux 8255 Port C Output BASE ADDRESS 13 Aux 8255 Control Register Table 6 1 A1216E Register Address Map Manual MA1216E D2a Page 6 1 A1216E Manual Register Definitions Status Register The Status register provides information about the operation and configuration of the analog input functions of the card Base 0 Read and Write Command and Status Register lar s es ysef oe m os so GATE2 GATE1 IRQ CHGCHV IT2 ADC2 ADCI ADCO CLKSEL CLKSEL Selects Counter 0 clock high selects internal
20. to which the equipment is exposed other than that use specified or intended as evidenced by purchase or sales representation Other than the above no other warranty expressed or implied shall apply to any and all such equipment furnished or sold by ACCES Page iv Table of Contents Notice an arca secre de ales E iN ee En Bie IN Tos ee e iii Warranty lt ka e kek O kur eyala oe bee Moby bod hede l a ka due eke Si eek iv Chapter 1 Introduction 2 32H A kk kk kk kk kk lk kk kk ka 1 1 Analoq pis HA asp a cake Mere A e a ee a tama cado ea Do e a daa as 1 1 Input System Expansion 5 ala u an kK kK KK kK KK KK KK KK KK KK KK KK KK KK KK KK KK KK kk 1 1 Discrete Digital V O tice c sa SER Hoes MERE Da A ki haj i DA DEW i Zan 1 2 Bounter Timer za a ee ee et 1 2 Analog OUIB L 8 eg a a E yan E E EE ra eyar BEE zes 1 2 Ihterr pts adornadas aa ee 2 bas Diet 1 3 Reference Voltage and Power Requirements 000 cee eee nen 1 3 Input Output Connections an ae ts kk kK KK KK kK KK KK KK KK KK KK KK KK KK KK kk 1 3 iii SOLA La a e le lee dn id ae San AN decada ud 1 3 Specifications s ss si twas rta en he det da ade 1 3 Chapter 2 Installation cece kk kk kk KK KK KK KI KK K K eee kk kk ka 2 1 ADR EEES SN DN A A A rr 2 1 3 5 Inch Diskette Installation ni ae kk KK KK KK KK KK KK KK O id 2 1 Directories Created on the Hard Disk kK KK KK KK KK KR KI KK ee
21. unsigned int BASE_ADDRESS Returns a two byte unsigned number that indicates the value of the A D data register This value represents the digital value ofthe most recently completed analog to digital conversion This routine does not wait for EOC Therefore 1f you use STARTCONVERSION followed immediately by this routine the data that you receive is from the previous conversion not the one just started See Using the Driver later in this section of the manual for more information All 16 bits are returned regardless of the data word size of the card s converter Any extra bits returned by the A D card are included even if irrelevant to the data For a definition of the returned bits see the card manual or register section of this manual unsigned integer RETRIEVEANALOGCONVERSION unsigned int BASE_ADDRESS As above in RETRIEVEANALOGDATA Only the bits that relate to the input voltage are returned right justified Any extra bits returned by the A D card are thrown away Use the RETRIEVEANALOGDATA function if you want the raw bits from the A D card SETCHANNEL unsigned int BASE_ADDRESS unsigned int CHANNEL This routine outputs the desired A D and sub multiplexer channel to the A D card The A D channel number is passed in the upper nibble of the lower byte of the parameter CHANNEL and the sub multiplexer channel if any is passed in the lower nibble Therefore to set A D channel 2 and multiplexer card channel 4 set CHANNEL to 2 16 4
22. 10623 Roselle Street San Diego CA 92121 Tel 619 550 9559 FAX 619 550 7322 www accesioproducts com
23. 1216E using the A1216E CDM exclusively will reduce the learning curve even further You need to use the MDM only for the most advanced features or for speed critical algorithms Card Driver Modules CDM Each Card Driver Module provides routines to access a specific A D card type All of the CDM s provide the same functionality eliminating most card specific software design issues These drivers are provided in the form of OBJ object files that can be linked to any language that supports the Pascal calling convention QuickBASIC VisualBASIC for DOS C C Fortran Assembler and Pascal just to name a few Each object file is named the same as the A D card six character part number making it easy to locate the driver to be used These CDMs allow a given application to be written for a multitude of A D card types without changing a single line of code To switch from one A D type to another simply re link the application with the new CDM s OBJ file This driver system is also upgradeable and allows various expansion options to be attached to the CDM files such as sub multiplexer cards statistical analysis libraries or dynamic load drivers Also the specification for the CDM is available and allows you to write CDM files for third party A D cards This greatly simplifies mixed vendor programming support Manual MA1216E D2a Page 4 1 A1216E Manual Card Driver Modules provide the following functions unsigned integer AD_NAME Returns
24. 2 2 Installing the Gar s stra cide ahl al edd cae ede hae di Aye e el ds n 2 4 Chapter 3 Hardware Configuration and Installation 3 1 Option Selection sa ncaa nean an a amd ra dd ali Diss 3 1 Selecting and Setting the Base Address ooooocoocooocc KK KK KK KK KK 3 5 Galibfratioh and Tesl lt sy 3 ee er 3 8 Chapter 4 Software ss si kak ie kak a kalk e nn 4 1 A1216E CDM Software Driver Reference 2 kK KK KK KK KK KK KK KK KK KK KK 4 1 Multiplexer Driver Module MDM kk kk kk kK KK KK KK KK eee 4 6 Chapter 5 CDM Driver Error List 4 kk kk kk kk kK KK nn 5 1 Chapter 6 Programming vicio id kk kk kk kK KK kK ee kk kk kk kk kk kk ka 6 1 A1216E Register Address Map ooooocccccco KK KK KI KK KI KK KK KK KK KK nn 6 1 Register Definitions kk kk kk kk kK kK KK KK KK Madea KK KK KK KK KK KK KK KK KK KK KK Ke 6 2 Programming Example de kk kk kk kK KK KK KK KK K KK KK KI KI aces KK KK KK KK KK KK KK Ke 6 6 Analog Quits oe ae a id a o La as 6 7 Counter Timer Registers i kk kk kk kK KK KK KK KK KK KK KK KK KK KK KK KK KK KK KK kk 6 8 Page v Chapter 7 A D Converter Applications ooooooocorrrnmmnmmoo 7 1 Connecting Analog Inputs 248 rer KK KK KK KK KK KK KK KK kk 7 1 Comments on Noise Interference 00 KK KK KK KK KK KK KK nennen 7 1 Ground IS _ _ m mean 7 2 External Noise kk kk kk kk kK KK KK KK KK KK KK a KK KK KK KK KK
25. ACCES I O PRODUCTS INC 10623 Roselle Street San Diego CA 92121 TEL 858 550 9559 _ FAX 858 550 7322 MODEL A1216E USER MANUAL FILE MA1216E D2a Notice The information in this document is provided for reference only ACCES does not assume any liability arising out of the application or use of the information or products described herein This document may contain or reference information and products protected by copyrights or patents and does not convey any license under the patent rights of ACCES nor the rights of others IBM PC PC XT and PC AT are registered trademarks of the International Business Machines Corporation Printed in USA Copyright 1995 by ACCES I O Products Inc 10623 Roselle Street San Diego CA 92121 All rights reserved Pageiii Warranty Prior to shipment ACCES equipment is thoroughly inspected and tested to applicable specifications However should equipment failure occur ACCES assures its customers that prompt service and support will be available All equipment originally manufactured by ACCES which is found to be defective will be repaired or replaced subject to the following considerations Terms and Conditions If a unit is suspected of failure contact ACCES Customer Service department Be prepared to give the unit model number serial number and a description of the failure symptom s We may suggest some simple tests to confirm the failure We will assign a Return Material Authorization
26. Controller 3F8 3FF Asynchronous Communication Primar Table 3 1 Standard Address Assignments For 286 386 486 Computers Page 3 6 Manual MA1216E D2a Setting the Base Address The A1216E base address is selected by DIP switch S1 located in the lower center portion of the card directly adjacent to the I O connector Switch S1 controls address bits AS through A9 Bits AO through A4 are used for the 20 address locations in I O space required by the A1216E The following procedure will show you how to set the base address See Table 3 2 for a graphic representation of this example 1 We will use base address 300 hex as an example Determine the binary representation for your base address In our example 300 the binary representation is 11 0000 0000 The conversion multipliers for each binary bit are contained in FIGURE 3 4 for reference 2 Locate switch S1 on the lower center of the card next to the AT Bus connector Note that there are 5 switches which will be used to set the first five bits in the binary representation from step 1 The last digit is always zero and therefore does need not be set 3 Note from Figure 3 2 Base Address Example that switch position A9 corresponds to the most significant bit in your binary representation For each bit in your binary representation if the bit is a one turn the corresponding switch off if the bit is zero turn the corresponding switch on Hex representation 3 Table 3 2 Base Address Examp
27. ES32 PCI This directory contains PCI bus specific programs and information If you are not using a PCI card this directory will not be installed SOURCE A utility program is provided with source code you can use to determine allocated resources at run time from your own programs in DOS PCIFind exe A utility for DOS and Windows to determine what base addresses and IRQs are allocated to installed PCI cards This program runs two versions depending on the operating system Windows 95 98 NT displays a GUI interface and modifies the registry When run from DOS or Windows3 x a text interface is used For information about the format of the registry key consult the card specific samples provided with the hardware In Windows NT NTioPCI SYS runs each time the computer 1s booted thereby refreshing the registry as PCI hardware is added or removed In Windows 95 98 NT PCIFind EXE places itself in the boot sequence of the OS to refresh the registry on each power up This program also provides some COM configuration when used with PCI COM ports Specifically 1t will configure compatible COM cards for IRQ sharing and multiple port issues WIN32IRQ This directory provides a generic interface for IRQ handling in Windows 95 98 NT Source code is provided for the driver greatly simplifying the creation of custom drivers for specific needs Samples are provided to demonstrate the use of the generic driver Note that the use of IRQs in near real time d
28. IM 16MPs This adapter is designed to be used with our standard 37 pin ribbon cable If you desire to construct a cable yourself the following chart provides the recommended pin connections The cable requires two 37 pin D type female connectors Use caution and ensure that no connection is made in the positions where unused is specified Gain selection bit0 Not supported by A 2166_______T 6 24 5 7 23 4 22 10 3 11 7 12 13 13 14 LL GND Analog Common LL GND Analog Common 23 Umsed_____ D Achamel0outpue ________ _ 9 Output channel 1 Channel 1 analog input Manual MA1216E D2a Page B 3 A1216E Manual A1216E to Additional Multiplexers Cable Adapter Assembly To support more than eight external multiplexers to the full 16 AIM 16MP capability of the A1216E a cable adapter is available This will expand the total capability to 256 channels When using all 16 AIM 16MPs in a system the two cable adaptors should be attached to a Y cable attached to the T O connector of the A1216E If you desire to construct a cable yourself the following chart provides the recommended pin connections The cable requires two 37 pin D type female connectors Use caution and ensure that no connections are made in the positions where unused is specified 2 30 3 Unused 6 Gain selection bit 2 _____ Not supported by Al2I6E 5 7 23 8 Address selection bitl____ Digital output 1 Cd 4 9 Address selection bit 2
29. RMA number which must appear on the outer label of the return package All units components should be properly packed for handling and returned with freight prepaid to the ACCES designated Service Center and will be returned to the customer s user s site freight prepaid and invoiced Coverage First Three Years Returned unit part will be repaired and or replaced at ACCES option with no charge for labor or parts not excluded by warranty Warranty commences with equipment shipment Following Years Throughout your equipment s lifetime ACCES stands ready to provide on site or in plant service at reasonable rates similar to those of other manufacturers in the industry Equipment Not Manufactured by ACCES Equipment provided but not manufactured by ACCES is warranted and will be repaired according to the terms and conditions of the respective equipment manufacturer s warranty General Under this Warranty liability of ACCES is limited to replacing repairing or issuing credit at ACCES discretion for any products which are proved to be defective during the warranty period In no case is ACCES liable for consequential or special damage arriving from use or misuse of our product The customer is responsible for all charges caused by modifications or additions to ACCES equipment not approved in writing by ACCES or if in ACCES opinion the equipment has been subjected to abnormal use Abnormal use for purposes of this warranty is defined as any use
30. Reading and Loading the Counters If you attempt to read the counters on the fly when there is a high input frequency you will most likely get erroneous data This is partly caused by carries rippling through the counter during the read operation Also the low and high bytes are read sequentially rather than simultaneously and thus it 1s possible that carries will be propagated from the low to the high byte during the read cycle To circumvent these problems you can perform a counter latch operation in advance of the read cycle To do this load the RW1 and RW2 bits with zeroes This instantly latches the count of the selected counter selected via the SC1 and SCO bits in a 16 bit hold register An alternative method of latching counter s which has an additional advantage of operating simultaneously on several counters 1s by use of a readback command to be discussed later A subsequent read operation on the selected counter returns the held value Latching is the best way to read a counter on the fly without disturbing the counting process You can only rely on directly read counter data if the counting process is suspended while reading by bringing the gate low or by halting the input pulses For each counter you must specify in advance the type of read or write operation that you intend to perform You have a choice of loading reading a the high byte of the count or b the low byte of the count or c the low byte followed by the high byte
31. To 1 Progam TT TE 1 WE Progam Comer See Reading and Loading the Counters Page 7 4 Page 6 8 Manual MA1216E D2a RWO RWl1 These bits select the read write mode of the selected counter Counter Read Write Function o fo Counter Latch Command o i Rewwae ts Bye ao Jo Read Write MS Byte Read Write LS Byte then MS Byte MO M2 These bits set the operational mode of the selected counter BCD Set the selected counter to count in binary BO 0 or BCD BO 1 Manual MA1216E D2a Page 6 9 A1216E Manual Page 6 10 Manual MA1216E D2a Chapter 7 A D Converter Applications Connecting Analog Inputs The A1216E offers optional switch selected eight channel differential or 16 channel single ended input configurations Single ended configuration means that you have only one input relative to ground A differential input uses two inputs and the signal corresponds to the voltage difference between these two inputs Although the single ended mode provides ability to accept 16 inputs rather than eight this configuration is not suitable for floating sources 1 e a signal source that does not have any connection to ground at the source Thus if the local ground for the signal source is isolated from the system ground the eight channel differential configuration should be used A differential input responds only to the difference in voltage levels between the high and low inputs In practice the signal source gro
32. a number that represents the name of the A D card that the specific Card Driver Module CDM supports unsigned integer MAXCHO Returns a number that indicates the maximum number of channels available The A1216E CDM returns 16 unsigned integer MAXIRQO Returns a number that indicates the highest IRQ that the card can access 15 unsigned integer VALIDIRQO Returns a bitmask 16 bit value with ones at valid IRQ possibilities START CONVERSION unsigned int BASE_ADDRESS Causes the A D card to begin an analog to digital conversion The only parameter is the base address of the card and the routine does not have a return value unsigned integer CHECKFOREOC unsigned int BASE_ADDRESS This function returns zero FALSE if the card is busy performing an analog conversion Otherwise it returns non zero TRUE The only parameter is the base address of the card unsigned integer WAITFOREOC unsigned int BASE_ADDRESS This function will monitor the status of EOC using CHECKFOREOC until either EOC occurs or a timeout occurs The timeout is defined as 262 144 occurrences of the check for EOC The actual timeout depends on the speed of the computer in use and can be determined by measurement The function returns TRUE non zero if 1t detected EOC and FALSE zero if the routine timed out The exact number it returns is the number of tries remaining before timeout occurs Page 4 2 Manual MA1216E D2a unsigned integer RETRIEVEANALOGDATA
33. aded Hardware Triggered Strobe This is similar to Programmable One Shot except that when the counter is triggered by the gate going high the counter output immediately goes high then goes low for one clock period at timeout producing a negative going strobe pulse The timeout is re triggerable i e a new cycle will commence if the gate goes high before a current cycle has timed out Generating Interrupts with the Counter Timer The A1216E architecture allows you to directly generate an interrupt upon an ADC end of conversion or the timeout of Counter 2 This allows you to either read the converted data or use the counter while using external start of conversions Note also that it is possible to trigger the A D externally or by a programmed write to an I O port and invoke an interrupt at the end of A D conversion in the same way Manual MA1216E D2a Page 8 7 A1216E Manual Page 8 8 Manual MA1216E D2a Chapter 9 D A Converters There are two independent double buffered 12 bit digital to analog converters on the A1216E card Data format is offset binary by default but two s complement may be enabled by installing jumper JP5 The maximum output voltage swing of the D A s is 10V Twelve bit accuracy is maintained at update rates up to 1 KHz Note When the 2 s complement option is enabled a bipolar range must be selected Note also that the 2 s complement option selection jumper JP5 also affects data format of the analog input
34. ange A D did not report EOC in time Buffer pointer is not valid or NULL There are no points in the list to acquire The IRQ selected is out of range The values selected cause buffer overflow The mode selected is not defined An error occurred in the parameter list Parameter 1 has an unknown error Parameter 2 has an unknown error Parameter 3 has an unknown error Parameter 4 has an unknown error Parameter 5 has an unknown error Parameter 6 has an unknown error Parameter 7 has an unknown error Parameter 8 has an unknown error Parameter 9 has an unknown error Parameter 10 has an unknown error The user pressed a key aborting the process The counter number is invalid The corner frequency selected is not possible Function not supported Warnings returned by the drivers AAF Only applies to AAF series cards WARN_CAL_OUT_OF_RANGE WARN_CAL_ABOVE_SCALE WARN_CAL_BELOW_SCALE WARN_RATE_TOO_FAST WARN_RATE_TOO_SLOW Manual MA1216E D2a 1 QN hu N AAFThe calibration value is so far out of range that the card may be failing or is badly calibrated AAF The offset calibration is gt 10 of FSV high AAF The offset calibration is gt 10 FSV low The sample rate is too fast for this process The sample rate is too slow for this process Page 5 1 A1216E Manual Page 5 2 Manual MA1216E D2a Chapter 6 Programming The previous chapter covered use of device drivers provided This chapter provides you with information on how
35. ata acquisition programs requires multi threaded application programming techniques and must be considered an intermediate to advanced programming topic Delphi C Builder and Visual C samples are provided Manual MA1216E D2a Page 2 3 A1216E Manual Findbase exe DOS utility to determine an available base address for ISA bus non Plug n Play cards Run this program once before the hardware is installed in the computer to determine an available address to give the card Once the address has been determined run the setup program provided with the hardware to see instructions on setting the address switch and various option selections Poly exe A generic utility to convert a table of data into an nth order polynomial Useful for calculating linearization polynomial coefficients for thermocouples and other non linear sensors Risc bat A batch file demonstrating the command line parameters of RISCTerm exe RISCTerm exe A dumb terminal type communication program designed for RS422 483 operation Used primarily with Remote Data Acquisition Pods and our RS422 483 serial communication product line Can be used to say hello to an installed modem RISCTerm stands for Really Incredibly Simple Communications TERMinal Installing the Card The following procedure will show you how to install the A1216E inside the computer 1 gt Page 2 4 Ensure that all options have been set as instructed by the setup software or as describ
36. ater than 0 Manual MA1216E D2a Page A 1 A1216E Manual The QUALITY can be used to indicate how good a particular solution is If the range of points is very wide or if the points make transition from negative to positive values then QUALITY will suffer accordingly For these cases 1t may be better to use multiple polynomials rather than just one As an example the following data are taken from the NIST tables for type T thermocouples A T m Tan Toza 8 0 Toms 100 150 200 250 300 350 400 If we take all the data and compute one 5th order polynomial the QUALITY is 473 543732 not very good Now divide the data into two polynomials one on the negative side including O and one on the positive side also using O The results will show a QUALITY of 90 732620 for the negative side and a QUALITY of 0 005131 for the positive side Thus by using two polynomials you have made the positive side very accurate and dramatically improved the negative side Accuracy of the negative side can be further improved by adding points For example add the following pairs to the negative side of the polynomial for a type T thermocouple If you run the new data the QUALITY is improved to 69 555611 but still perhaps not as good as you would like Thus you may use the QUALITY as a means to determine how good the polynomial is You can experiment with both order and number of data points until you are satisfied with the solution Incidentally th
37. ddress 1 Check Table 3 1 for a list of standard address assignments and then check what addresses are used by any other 1 O peripherals that are installed in your computer Memory addressing is separate from I O addressing so there is no possible conflict with any add on memory that may be installed in your computer We urge that you carefully review the address assignment table before selecting a card address If the addresses of two installed functions overlap unpredictable computer behavior will result From this list or using the base address function in the SETUP EXE software select an unused portion of 20 consecutive bytes of I O addresses Note from the tables that the sections 100 1F0 280 2EF and 330 36F are normally unused These address spaces are good areas to select for the base address Also if you are not using a given device listed in the tables then you may use that base address as well For example since most computers do not have a prototype card installed then base address 300 hex is a good choice for a base address Finally make sure that the base address you have chosen is a multiple of Hex 20 This insures that your base address is on a 32 bit boundary Note The hexadecimal numbering system is used in this manual for addresses Data values are in binary or decimal values unless marked with an h suffix for hexadecimal values Manual MA1216E D2a Page 3 5 A1216E Manual OFO OF 3F0 3F7 Floppy Diskette
38. digital inputs providing a total of up to eight Digital Inputs at the rear panel connector The auxiliary digital I O port is from an 8255 Programmable Peripheral Interface which provides 24 bits of bi directional input output bits configured as two sets of eight bit and two sets of four bit digital input output ports This port is extended using a ribbon cable from the board to a 37 pin connector on an auxiliary rear mounting bracket Counter Timer The A1216E contains a type 8254 counter timer which has three 16 bit programmable down counters Counter Timer 0 is enabled by a digital input IP2 and uses either the internal 1MHz clock or an external clock of up to 10 MHZ Counter Timers 1 and 2 are concatenated and form a 32 bit counter timer for timed A D trigger pulses and or external frequency generation The dual counter timer can be enabled by program control and clocked by a 1 MHZ on board crystal oscillator source Counter 2 may be set to generate an interrupt request IRQ upon completion of a counter period Counter Timer 0 and Counter Timers 1 and 2 can be set up for event counting frequency or period measurements and pulse or wave form generation Also Counter Timers 1 and 2 can be programmed to initiate A D conversions See the Programmable Interval Timer section of this manual for a description of ways that the type 8254 counter timer chip can be used Analog Output The A1216E has two 12 bit digital to analog converters D A
39. e A1216E card features are selected by hardware jumpers or switches At least one of each of the option categories must be selected if the card is to operate correctly The setup program provided with the card provides menu driven pictorial presentations to help you quickly set up the card You may also refer to the Option Selection Map and the following sections to set up the card The card need not be plugged into the computer at this time Multiplexer Configuration Select the desired A D input multiplexer configuration by moving JP8 and JP9 jumpers to the appropriate position 8 Channel Differential Input DIF position 16 Channel Single Ended Input SE position Unipolar Bipolar Range In the unipolar mode inputs can be positive only i e ranges from zero volts to some positive voltage The maximum voltage span in the unipolar mode is 10V In the bipolar mode inputs can be between positive and negative full scale limits In the unipolar range the JP3 Gain jumper must be in the x2 position Select the unipolar or bipolar range using jumper JP4 located in the upper right hand corner of the card near the I O connector Unipolar UNIP position Bipolar BIP position The two s complement jumper JP5 is an option for bipolar ranges which changes the data format for both the ADC analog input and DAC analog output data registers External Conditioning Module Support AIM 16 jumper JP10 sets the internal programmable gain amplifier to a u
40. e registers when writing 32 bit Windows software Several samples are provided in a variety of languages to demonstrate how to use this driver The DLL provides four functions InPortB OutPortB InPort and OutPort to access the hardware This directory also contains the device driver for Windows NT ACCESNT SYS This device driver provides register level hardware access in Windows NT Two methods of using the driver are available through ACCES32 DLL recommended and through the DevicelOControl handles provided by ACCESNT SYS slightly faster Page 2 2 Manual MA1216E D2a SAMPLES Samples for using ACCES32 DLL are provided in this directory Using this DLL not only makes the hardware programming easier MUCH easier but also one source file can be used for both Windows 95 98 and WindowsNT One executable can run under both operating systems and still have full access to the hardware registers The DLL is used exactly like any other DLL so it is compatible with any language capable of using 32 bit DLLs Consult the manuals provided with your language s compiler for information on using DLLs in your specific environment VBACCES This directory contains sixteen bit DLL drivers for use with VisualBASIC 3 0 and Windows 3 1 only These drivers provide four functions similar to the ACCES32 DLL However this DLL is only compatible with 16 bit executables Migration from 16 bit to 32 bit is simplified because of the similarity between VBACCES and ACC
41. e the Error List for descriptions of error codes integer GETADDMADATA unsigned int BASE unsigned int FIRSTCH unsigned int LASTCH unsigned int SCANS unsigned int BUFFER unsigned int DMAautoinit unsigned int DMAchannel unsigned int IRQnumber This routine will use DMA to acquire data in the background at a programmed rate This routine will return an error value with the A1216E which does not support DMA operations int GETADIRQDATAO Reserved for future use This routine will use IRQ s to acquire data in background at a programmed rate int GETADINSDATAO Reserved for future use This routine will use InputStringOfData ASM instructions to acquire data from a FIFO or RAM equipped card in the background at a programmed rate Manual MA1216E D2a Using the CDM Driver The CDM driver is straightforward to use and varies little even across languages Each CDM is an object file and has several include files associated with it The C and C include files are called ACCES H and ADCARD H The Pascal interface files are called ACCES INT and ADCARD INT Examples are provided on CD to illustrate use of these files Each language has its own directory and each directory contains the sample s the CDM OBJ files and the associated include file s Using the driver consists of writing the desired program with the appropriate include files compiling this program and then linking the resultant object files with the CDM object file into an executable
42. ed in the Hardware Configuration and Installation chapter Be sure to pay close attention to base address selection Turn off the power switch of your computer and remove the power cords from the wall outlet Remove the computer cover Locate an unused three quarter slot and remove blank I O backplate Optionally remove a second backplate for the auxiliary digital I O port Insert the card in the slot and install the I O backplate screw Install the auxiliary connector backplate and connect via a ribbon cable extension from the 40 pin IDC connector Inspect the installation for proper fit and seating of the card Replace the computer cover and re apply power to the computer If you wish you may now confirm the calibration and proper operation of the card by running the calibration portion of the SETUP software Manual MA1216E D2a Caution Failure to completely remove power from the computer could result in hazard to the card computer and yourself To ensure that there is minimum susceptibility to EMI and minimum radiation it is important that there be a positive chassis ground Also proper EMI cabling techniques cable connect to chassis ground at the aperture twisted pair wiring and in extreme cases ferrite level of EMI protection must be used for input output wiring Manual MA1216E D2a Page 2 5 A1216E Manual Page 2 6 Manual MA1216E D2a Chapter 3 Hardware Configuration and Installation Option Selection Many of th
43. elect the voltage range as described in the following table Desired Output Voltage Range Switches S2 and S3 Position 2 Position 3 O O O N FF FF Page 3 2 Manual MA1216E D2a Eur Figure 3 1 A1216E Option Selection Map Connectors J1 37 Pin Male D Connector Primary Analog on rear panel backplate J2 40 Pin Male IDC Ribbon Cable Connector Aux Digital I O connects to second rear panel connector Switches S1 Base Address Selection A5 A9 S2 DACO Output options S3 DACI Output options Manual MA1216E D2a Page 3 3 A1216E Manual Option Jumpers JP1 End of Conversion IRQ selection IRQ2 7 JP2 End of Conversion IRQ selection IRQ10 15 JP3 Analog Converter Input Range X1 X2 JP4 Analog Input Polarity Unipolar or Bipolar JP5 DAC ADC Data Format 2 s Complement if installed Offset Binary coding if removed JP6 AIM 16 Compatibility Jumper Grounds Channel 8 pin 18 Input when installed JP7 AIM 16 Compatibility Jumper Grounds Channel 15 pin 11 Input when installed JP8 Selects Single Ended Differential Analog Input Must be set the same as JP9 below JP9 Selects Single Ended Differential Analog Input Must be set the same as JP8 above JP10 AIM 16 Compatibility Jumper Sets internal A1216E PGA
44. ess of the A D card and then call the MDM function to acquire data from the card Next the returned data from the buffer is manipulated and or displayed and the process repeated as desired To use the function calls provided by the MDM the program must include the interface file such as SSH 0x H The source program s object file user obj must be linked with the CDM object file ADCARD OBJ where ADCARD is the 6 character A D model number such as A1216E and the MDM object file such as SSH 0x OBJ Manual MA1216E D2a Page 4 7 A1216E Manual Page 4 8 Manual MA1216E D2a Chapter 5 CDM Driver Error List The following constants are defined by the CDM include files and are available to your programs The ERROR codes report a non recoverable error and require action to be taken before the process can be continued Warnings report conditions that usually indicate trouble Errors returned by the Drivers ERR_INVALID_ADDRESS ERR_CHANNEL_RANGE ERR_AD_TIMEOUT ERR_NULL_POINTER ERR_NO_POINTS ERR_IRQ_ RANGE ERR_BUFFER_OVERFLOW ERR_BAD_MODE ERR_BAD_PARAMETER_LIST ERR_PARAMETER 1 ERR_PARAMETER 2 ERR_PARAMETER 3 ERR_PARAMETER 4 ERR_PARAMETER 5 ERR_PARAMETER 6 ERR_PARAMETER 7 ERR_PARAMETER 8 ERR_PARAMETER 9 ERR_PARAMETER 10 ERR_USER_ABORT ERR_BAD_COUNTER ERR_BAD_CORNER_FREQUENCY ERR_NOT_SUPPORTED AADNBRWN A No 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Base address is out of range Channel number is out of r
45. example if 50 000 decimal is to be loaded into a 16 bit counter an easy way to convert this to binary is to enter BASIC and execute PRINT HEX 50000 This returns C350 which in binary form is 11000011 0101 0000 Since the most significant bit is a one this would be stored as a negative integer and in fact the correct integer variable value would be 50 000 65 536 15 536 Manual MA1216E D2a Page C 1 A1216E Manual Page C 2 Manual MA1216E D2a Appendix D PPI Data Sheets The data sheets in this Appendix are provided to help your understanding of the 8255 5 PPI which is made by a number of companies These sheets are reprinted with permission of Mitsubishi Electric Corp Copyright 1987 The information diagrams and all other data included are believed to be correct and reliable However no responsibility is assumed by Mitsubishi Electric Corporation for their use nor for any infringements of patents or other rights belonging to third parties which may result from their use Values shown on these data sheets are subject to change for product improvement Manual MA1216E D2a Page D 1 A1216E Manual Page D 2 Manual MA1216E D2a Customer Comments If you experience any problems with this manual or just want to give us some feedback please email us at manuals accesioproducts com Please detail any errors you find and include your mailing address so that we can send you any manual updates ya ACCES I O PRODUCTS INC
46. ferential Hi Lo Gnd or 16 single ended e Resolution 12 binary bits e Accuracy 0 1 of reading 1 bit typical Calibrated at 0 10V and 10V e Voltage Range Software and switch selectable 10V 5V 1V 0 5V 0 1V 0 05 V 0 01V 0 005V 0 10V 0 1V 0 0 1V 0 0 01V e Coding True binary or two s complement by jumper selection Input Impedance 15 MQ CMRR 80 dB Common Mode Rejection Ratio with differential inputs e CMVR 12 VDC Common Mode Voltage Rejection with differential inputs Manual MA1216E D2a Page 1 3 A1216E Manual A D Specification Type Resolution Conversion Time Monotonicity Linearity Zero Drift Gain Drift Successive approximation Analog Devices 7804 12 binary bits 10 usec max 8 psec typical Guaranteed over operating temperature range l bit 3 50 V 9C maximum 5 ppm C if gain lt 100 42 ppm C if gain 100 100 ppm C if gain 1000 Trigger Source Software selectable external trigger programmable timer or program command Sample and Hold Amplifier Internal Acquisition Time D A Specification Channels Type Coding Non Linearity Monotonicity Output Range Output Drive Output Resistance Settling Time Digital VO 8 Bits on Main 37 Pin D Connector Inputs Logic high Logic low Outputs Logic high Logic low Page 1 4 2 microsecond typical for full scale step function input resulting in
47. for the A D converter Due to connector contact resistance and cable resistance there may be many millivolts difference between the two grounds even though they are connected together and to the computer and power line grounds on the A1216E card Manual MA1216E D2a Page 7 3 A1216E Manual Page 7 4 Manual MA1216E D2a Chapter 8 Programmable Interval Timer The A1216E contains a type 8254 programmable counter timer which allows you to implement such functions as a Real Time Clock Event Counter Digital One Shot Programmable Rate Generator Square Wave Generator Binary Rate Multiplier Complex Wave Generator and or a Motor Controller The 8254 is a flexible but powerful device that consists of three independent 16 bit presettable down counters Each counter can be programmed to any count between 1 or 2 and 65 535 in binary format depending on the mode chosen On the A1216E these three counters are designated Counter 0 Counter 1 and Counter 2 Counter 0 is un dedicated with the gate output and clock connections fully accessible via the I O connector Counter 0 is enabled by a discrete input and uses either the internal IMHz clock or an external clock of up to IOMHz Counters 1 and 2 are cascaded together to form a 32 bit counter This dual counter can be enabled gated by program control and is clocked by a 1MHz precision crystal controlled internal source Operational Modes The 8254 modes of operation are described in the fol
48. g after the rising edge of the trigger input and will go low for one clock period when the terminal count is reached The counter is retriggerable The output will not go low until the full count after the rising edge of the trigger Prog ramming On the A1216E the 8254 counters occupy the following addresses Base Address C Read Write Counter 0 Base Address D Read Write Counter 1 Base Address E Read Write Counter 2 Base Address F Write to Counter Control register The counters are programmed by writing a control byte into a counter control register at Base Address F The control byte specifies the counter to be programmed the counter mode the type of read write operation and the modulus The control byte format is as follows Base F Write Counter Control Byte Page 8 2 Manual MA1216E D2a SCO SC1 These bits select the counter that the control byte is destined for lo 0 Program Counter 0__ To 1 mmgamcomers 1 10 Progam Comer See section on Reading and Loading the Counters RWO RWI1 These bits select the read write mode of the selected counter Counter Read Write Function o jo Counter Latch Command oe A Read Write LS Byte a fo Read Write MS Byte Read Write LS Byte then MS Byte MO M2 These bits set the operational mode of the selected counter BCD Set the selected counter to count in binary BO 0 or BCD BO 1 Manual MA1216E D2a Page 8 3 A1216E Manual
49. ge Base 6 Read Contains the lower four bits of the A D converter output in binary form or two s complement by jumper selection AAA A ADO AD3 The lower four bits of the A D conversion ADO is the least significant bit Base 7 Read Contains the upper eight bits of the A D converter output in binary form or two s complement by jumper selection AAA A AD4 AD11 The most significant eight bits of the A D conversion AD11 is the most significant bit Note It is possible to read all 12 bits of analog data in one operation using inport inpw portw or similar function in other languages Page 6 4 Manual MA1216E D2a Digital I O Digital 1 O available consists of two ports four input bits IPO IP3 and four tri stateable input output bits OPO OP3 one set on the 37 pin rear panel D connector and 24 bits on a 40 pin IDC connector on the board In addition two of the input port lines do double duty IPO is the also the external A D start conversion trigger and IP2 is the gate input for Counter 0 of the Counter Timer These secondary functions may or may not be used depending on the application Base 1 Write Write Digital Output and Tri State Enable Control Byte OPO Input Output bit OPO if ENO is low then OPO is in tristate input mode OP1 Input Output bit OP1 if EN1 is low then OP1 is in tristate input mode OP2 Input Output bit OP2 if EN2 is low then OP2 is in tristate input mode OP3 Input Output bit OP3
50. hree month interval is suggested For laboratory or office conditions six months to a year is acceptable A 41 digit digital multimeter is required as a minimum to perform satisfactory calibration Also a voltage calibrator or a stable noise free DC voltage source that can be used in conjunction with the digital multimeter is required Calibration is performed using the A1216E setup program SETUP EXE on the CD supplied with your card This program will lead you through the configuration and calibration procedure with prompts and graphic displays that show the settings and adjustment trim pots This calibration program also serves as a useful test of the A1216E A D and D A functions and can aid in troubleshooting if problems arise Calibration Procedure The following procedure is brief and is intended for use in conjunction with the calibration part of the A1216E program 1 Run the setup and calibration software to confirm proper configuration of the card for calibration For the A1216E the proper setup is single ended bipolar 10V input range 2 Install the card and run the setup and calibration program 3 Use the arrow keys to select Calibration then select A D or D A calibration 4 Follow the instruction to perform the calibration procedure and test Page 3 8 Manual MA1216E D2a Chapter 4 Software A1216E CDM Software Driver Reference Although it is possible to write an application program for the A1216E card using direct
51. if EN3 is low then OP3 is in tristate input mode ENO Writing high enables OPO low tristates bit allowing input operations EN1 Writing high enables OP1 low tristates bit allowing input operations EN2 Writing high enables OP2 low tristates bit allowing input operations EN3 Writing high enables OP3 low tristates bit allowing input operations Base 1 Read Read Digital Input Byte Any read to this address clears the IRQ status flag TT TT ET E A ET TIR IP3 IP2 COG IPI IPO TRIG OP3 OP2 op oo OPO Input bit OPO if ENO is low OP1 Input bit OP1 if EN1 is low OP2 Input bit OP2 if EN2 is low OP3 Input bit OP3 if EN3 is low IPO TRIG Input bit Optional ADC start input TRIG 0 if ADC1 true at base 0 IP1 Input bit IP2 COG Input bit Shared with Counter 0 enable gate COG IP3 Input bit Base 10 Read Write Parallel Peripheral Interface 8255 Port A AAA Eight bits of digital input output Data written to the port may be readback from the same address Manual MA1216E D2a Page 6 5 A1216E Manual Base 11 Read Write Parallel Peripheral Interface 8255 Port B Same format as above Base 12 Read Write Parallel Peripheral Interface 8255 Port C Same format as above Base 13 Write Parallel Peripheral Interface 8255 Command Byte AA ae A A ee A TA Tan Mode Al Mode AO See below or the 8255 Programmable Peripheral Interface Appendix D for programming instructions and example applicat
52. ion information Note In Mode 0 do not use the control register byte for the individual bit control feature The hardware uses the I O bits to control buffer direction on this card The control register should only be used for setting up input and output of the ports and enabling the buffer Programming Example The following example in BASIC is provided as a guide to assist you in developing your working software In this example the card base address is 2CO hex and I O lines of Port 0 are to be setup as follows Port A Input Port C Hi Input Port B Output Port C Lo Output The first step is to configure the control register Configure bits of the control register as D7 D6 D5 D4 D3 D2 D1 DO 1 0 0 1 1 0 0 0 l____ Port C Lo output l Port B output l Mode 0 Port C Hi input Port A input Mode 0 Mode 0 Active Mode Set Page 6 6 Manual MA1216E D2a This corresponds to 98 hex If the card address is 2CO hex use the C command to write to the control register as follows BASE 0x2C0 OUTPORTB Base 0x 13 0x98 To read the inputs at Port A and the upper nybble of Port C X INPORTB BASE 0x10 Read Port A Y INPORTB BASE 0x12 16 Read Port C Hi To set outputs high 1 at Port B and the lower nybble of Port C OUTPORTB BASE 0x11 0xFF Turn on all Port B bits OUTPORTB BASE 0x12 0xF Turn on all bits of Port C lower nybble Analog Outputs D A Converter DAC registers are write only registe
53. ion of the gate input signal Longer pulse durations can be measured if Counters 1 and 2 are used as the input clock source for Counter 0 or by using an external clock source Generating Time Delays There are four methods of using Counter 0 to generate programmable time delays Pulse on Terminal Count After loading the counter output goes low Counting is enabled when the gate goes high The counter output will remain low until the count reaches zero at which time the counter output goes high The output will remain high until the counter is reloaded by a programmed command If the gate goes low during countdown counting will be disabled as long as the gate input is low Programmable One Shot The counter need only be loaded once The time delay is initiated when the gate input goes high At this point the counter output goes low If the gate input goes low counting continues but a new cycle will be initiated if the gate input goes high again before the timeout delay has expired i e is re triggerable At the end of the timeout the counter reaches zero and the counter output goes high That output will remain high until re triggered by the gate input Page 8 6 Manual MA1216E D2a Software Triggered Strobe This is similar to Pulse on Terminal Count except that after loading the output goes high and only goes low for one clock period upon timeout Thus a negative strobe pulse is generated a programmed duration after the counter is lo
54. is example also shows that the smaller the range of x values the better the solution Page A 2 Manual MA1216E D2a Appendix B Cabling and Connector Information A1216E Primary Connector Pin Assignments Connections are made to the A1216E card via a 37 pin D type connector that extends through the back of the computer case and a second 40 pin IDC connector on the board Pin Nam Fa 3 CA AAA _s Al Digital inot OOOO _s Unused Used OOOO _o DAC0 OUT D A Channel 0 Output SO 10 Chl 7 Analog Low Input diff l Chl 15 Analog High Input s e Chl 6 Analog Low Input diff l Chl 14 Analog High Input s e Chl 5 Analog Low Input diff l Chl 13 Analog High Input s e Chl 4 Analog Low Input diff l Chl 12 Analog High Input s e Chl 3 Analog Low Input diff Chl 11 Analog High Input s e Chl 2 Analog Low Input diff l Chl 10 Analog High Input s e Chl 1 Analog Low Input diff l Chl 9 Analog High Input s e Chl 0 Analog Low Input diff l Chl 8 Analog High Input s e 3 oro Digital Output 155 22 Dis gital Input g Unused Low Level Ground Analog Common Chl 5 Analog High Input LCHOHL 0 HI Ana Hihi os Lich Inn Table B 1 A1216E Primary Connector Pin Assignments The 37 pin female mating connector can be a Cannon DC 37S for soldered connections or insulation displacement flat cable types such as AMP 745242 1 may be used The wiring may be directly from the signal sources or may be on ribbon cable Man
55. ivide the full scale voltage range by the number of parts of resolution For example for a unipolar range of 0 10 volts a 12 bit A D resolves the input into 4096 parts Thus voltage resolution the weight of one bit is 2 44 mV For a bipolar range of 10V one LSB is worth 4 88mV If an amplifier is incorporated in the circuit providing gain then divide the voltage resolution by the gain of the amplifier For example a 12 bit A D with 10V full scale input range and an amplifier gain of 100 will provide an overall input resolution of about 49 UV Page 7 2 Manual MA1216E D2a Current Measurements Current signals can be converted to voltage for measurement by the A D converter by addition of a shunt resistor installed across the input terminals For example to accommodate 4 20 mA current transmitter inputs connect a 25002 shunt resistor across the A D input terminals The resultant 1 5V signal can then be measured If an AIM 16P multiplexer expansion board is being used pre wired pads are provided on the AIM 16 If all the inputs are 4 20mA range current inputs from current transmitters then there is a configuration of the multiplexer expansion board called AIM 16IP That model includes the shunt resistors and has offset and gain set such that the live zero is compensated for and the full 12 bit resolution of the A D is realized Note Accuracy of measurement will be directly affected by the accuracy of these resistors Accordingly
56. le MEA RE Suri as Settings i Conversion multiplier Switch ID apa AA Using the Setup Program to Set the Base Address The setup program provided with A1216E contains an interactive menu driven program to assist you in setting the base address The following procedure demonstrates the use of the setup program With the board removed from the PC Select an initial desired base address Run the setup program by typing SETUP EXE and pressing the ENTER key Select the first item in the menu Set board address with the arrow key and press ENTER The setup program will use our FINDBASE technology to build a list of addresses available in your computer for the A1216E You may press the arrow keys to choose a different address from the list or type your desired address using the numeric entry keys You may wish to enter your own address if the A1216E is already in your system and you are preparing to perform a calibration or diagnostic test Once an address is selected a graphic display will illustrate the proper setting of the onboard switches 5 Set DIP switch S1 as shown on the graphic representation BD Manual MA1216E D2a Page 3 7 A1216E Manual Calibration and Test Periodic calibration of A1216E is recommended to retain full accuracy The calibration interval depends to a large extent on the type of service that the card experiences For environments where there are frequent large changes of temperature and or vibration a t
57. lowing paragraphs to familiarize you with the versatility and power of this device For those interested in more detailed information a full description of the 8254 programmable interval timer can be found in the Intel or equivalent manufacturers data sheets The following conventions apply for use in describing operation of the 8254 Clock A positive pulse into the counter s clock input Trigger A rising edge input to the counter s gate input Counter Loading Programming of a binary count into the counter Mode 0 Pulse on Terminal Count After the counter is loaded the output is set low and will remain low until the counter decrements to zero The output then goes high and remains high until a new count is loaded into the counter A trigger enables the counter to start decrementing This mode is commonly used for event counting with Counter 0 Mode 1 Retriggerable One shot The output goes low on the clock pulse following a trigger to begin the one shot pulse and goes high when the counter reaches zero Additional triggers result in reloading the count and starting the cycle over If a trigger occurs before the counter decrements to zero a new count is loaded Thus this forms a re triggerable one shot In mode 1 a low output pulse is provided with a period equal to the counter count down time Manual MA1216E D2a Page 8 1 A1216E Manual Mode 2 Rate Generator This mode provides a divide by N capability where N is the count loaded
58. n the counter status byte are set low and the RW1 and RWO bits have both been previously set high in the counter control register thus selecting two byte reads then reading a selected counter address location will yield 1st Read Status byte 2nd Read Low byte of latched data 3rd Read High byte of latched data After any latching operation of a counter the contents of its hold register must be read before any subsequent latches of that counter will have any effect If a status latch command is issued before the hold register is read then the first read will read the status not the latched value In this case the latched value may be read after reading the status Programming Examples Generating a Square Wave Output To program Counters 1 and 2 for a 1 KHz output you need to divide the 1MHz crystal oscillator input by 1 000 To obtain a symmetrical waveform the divisor loaded into the counter should be an even number If it is an odd number then one half of the waveform would be one input clock pulse period longer than the other A convenient divisor to use in counter 1 is 10 and counter 2 is 100 because 10 x 100 1 000 outportb BASEADDRESS F 0x76 counter 1 to square wave mode outportb BASEADDRESS F 0xb6 counter 2 to square wave mode outportb BASEADDRESS D 10 write lower byte counter 1 outportb BASEADDRESS D 0 write upper byte counter 1 outportb BASEADDRESS E 100 write lowe
59. nity gain to simplify software programming External conditioning modules are supported such as the AIM 16 series with MDM driver modules as described in the SOFTWARE SECTION Additionally extra grounds are available on pins 18 Channel 8 and 11 Channel 15 by installing respective AIM 16 jumpers JP6 and JP7 Manual MA1216E D2a Page 3 1 A1216E Manual Input Voltage Range Input voltage range is selected by the combination of the software gain setting and the span of the input range selected by on board jumpers The following table relates voltage range to the gain required Desired Input Range Software Gain Unipolar 10V Bipolar 10V Bipolar 20V Set x2 jumper set x2 jumper set x1 jumper set Note The A1216E should be configured for 5V inputs for compatibility with external modules using this range Ifthe two s complement data option is enabled it will also change the DAC output data register into the two s complement data format Analog Output Voltage Range Output voltage range is selected manually by on board switches Each analog output has a three switch group that selects the options Switch S2 is for DACO and S3 is for DAC1 Refer to the Option Selection Map or the setup software for their locations The two s complement data format jumper JP5 also changes the data format of the DAC registers and must be considered in its use Position 1 on each switch selects between unipolar or bipolar operation Positions 2 and 3 s
60. nput to your system and f x is the resulting output To run the program type POLY and lt ENTER gt at the command line The program will then prompt you for the desired order of the polynomial then the number of pairs that you wish to use to generate the polynomial You then enter the data pairs and the polynomial is computed and displayed For example given the following data points let s generate a 5th order polynomial to approximate this function The order of the polynomial that you desire will be 5 and the number of data points that you enter will be 11 After the data points are entered the program gives the following output For the polynomial f x C 0 C 1 x1 C 2 x2 C 3 x3 C 4 x4 C 5 x5 the coefficients are COEFFICIENT 5 0 003151 COEFFICIENT 4 0 081942 COEFFICIENT 3 0 740668 COEFFICIENT 2 2 635998 COEFFICIENT 1 2 816607 COEFFICIENT 0 2 956044 QUALITY OF SOLUTION sum of the errors squared 2 797989 The goal is to make the quality as close to 0 as possible The program checks the resulting polynomial with the data pairs that you entered It computes the f x values for each x value entered using the polynomial subtracts the result from the supplied value of f x and then squares the result The squared results are then summed to compute the QUALITY If the computed f x values were exact this value would be 0 But since this is an approximation this value will usually be something gre
61. precision resistors should be used Also if the ambient temperature will vary significantly these precision resistors should be low temperature coefficient wire wound resistors Measuring Large Voltages Voltages larger than the input range of the A D can be measured by using a voltage divider As above it is necessary to use precision resistors Also if the raw voltage is a direct analog of a parameter being measured then it will be necessary to apply a scale factor in software in order to arrive at the correct engineering units Precautions Noise Ground Loops and Overloads Unavoidably data acquisition applications involve connecting external things to the computer Do Not get inputs mixed up with the AC line An inadvertent short can instantly cause extensive damage As an aid to avoid this problem a Avoid direct connection to the AC line b Make sure that all connections are secure so that signal wires are not likely to come loose and short to high voltages c Use isolation amplifiers and transformers where necessary There are two types of ground connections on the rear connector of A1216E These are called Power Ground and Low Level Ground Power ground is the noisy or dirty ground that is meant to carry all digital signals and heavy power supply currents Low Level Ground is the signal ground for all analog input functions It is only meant to carry signal currents less than a few milliamperes and 1s the ground reference
62. r byte counter 2 outportb BASEADDRESS E 0 write upper byte counter 2 Manual MA1216E D2a Page 8 5 A1216E Manual Using Counter 0 as a Pulse Counter Since the counters are down counters the resulting count is subtracted from the starting value to determine the number of pulses This example starts with a value of 65 535 outportb BASEADDRESS F 0x30 counter 0 mode O outportb BASEADDRESS C 0xff counter 0 low load byte outportb BASEADDRESS C 0xff counter 0 high load byte Measuring Frequency and Period The two previous sections show how to count pulses and generate output frequencies It is also possible to measure frequency by raising the gate input of Counter 0 for a known time interval and counting the number of clock pulses accumulated for that interval The gating signal can be derived from Counters 1 and 2 operating in a square wave mode Counter 0 can also be used to measure pulse width or half period of a periodic signal The signal should be applied to the gate input of Counter 0 and a known frequency such as the IMHz crystal controlled oscillator applied to the Counter 0 clock input During the interval when the gate input is low Counter 0 is loaded with a full count of 65 535 When the gate input goes high the counter begins decrementing until the gate input goes back low at the end of the pulse The counter is then read and the change in count is a linear function of the durat
63. registers Programming Since the data are 12 bits wide it has to be written to each D A in two consecutive bytes The first byte contains the eight least significant bits of data and the second byte contains the four most significant bits of data The least significant byte should be written first and is stored in an intermediate register in the D A with no effect on the output When the most significant byte is written it s value is added to the stored least significant data and presented broadside to the D A converter thus assuring a single step update Note that the twelve bits of the output data are right justified within the 16 bit word Locations of the D A registers are Base Address 8 D A 0 Low Byte Base Address 9 D A 0 High Byte Base Address A D A 1 Low Byte Base Address B D A 1 High Byte The data format is Least significant byte DAO DA7 Least significant bits of the output value Most significant byte 5 e I s Is fm DA9 DA8 DA11 The four most significant bits of the output x Don t care bits It is good programming practice to set these to 0 Manual MA1216E D2a Page 9 1 A1216E Manual The following example shows how to output data in C and is readily translatable to other languages Since the D As have 12 bit resolution data should be in the range 0 to 4095 decimal or two s complement if selected by the jumper JP5 on the card unsigned value this is our output va
64. riable value 2048 we will output half scale outportb base_address 8 value amp Oxff extract and output lower byte of count outportb base_address 9 value 256 extract and output upper byte of count An assembly language routine is even simpler Assume AX contains the data and DX contains the card base I O address 8 To write to D A 0 OUT DX AX write to D A 0 Page 9 2 Manual MA1216E D2a Appendix A Linearization A common requirement encountered in data acquisition is to linearize or compensate the output of non linear transducers such as thermocouples flowmeters etc The starting point for any linearizing algorithm is a knowledge of the calibration curve input output behavior of the transducer This may be derived experimentally or may be available in manufacturer s data or standard tables There are several approaches to linearization The two most common are piecewise linearization using look up tables and use of a mathematical function to approximate the non linearity Amongst the mathematical methods polynomial expansion is one of the easiest to implement The utility program POLY EXE allows you to generate up to a 10th order polynomial approximation For most practical applications a fifth order polynomial approximation is usually adequate Before you start the program have the desired input output data or calibration data handy This will be in the form of x and f x values where x is the i
65. rs and require a low byte high byte write sequence to load the 12 bit DAC s Note that the registers are double buffered so that the DAC s are not updated until the second high byte is written Thus you can write the low bytes to DAC s O and 1 first and then the high bytes to DAC s O and 1 This ensures near simultaneous transition of the analog outputs Register data are true offset binary and right justified or two s complement by jumper selection Base 8 Write Write DAC 0 least significant byte DAO DA7 Least significant eight bits of the DAC 0 output value DAO is the least significant bit Base 9 Write Write DAC 0 most significant byte DA8 DA11 The four most significant bits of the DAC 0 output DA11 is the most significant bit Base A Write Write DAC 1 least significant byte The format is the same as base 8 Base B Write Write DAC 1 most significant byte The format is the same as base 9 Manual MA1216E D2a Page 6 7 A1216E Manual Counter Timer Registers The type 8254 counter timer chip used contains three 16 bit counters Counters 1 and 2 are cascaded and driven by a 1 MHz clock for periodic triggering of the A D Periods of a few microseconds to in excess of an hour can be programmed Counter 0 is uncommitted and provides a gated 16 bit binary counter that can be used for event or pulse counting delayed triggering or in conjunction with other channels for frequency or period measurement Counter
66. rsion Gain Amplifier Setting 0 0 x1 0 1 x 10 1 0 x 100 1 1 x 1000 SE BAL Read only reports single ended high or differential low mode The state is latched by the last write operation to Base 2 BUSY Read only high during ADC conversion process Start and Command Registers These registers initiate actions upon read or writes to their address The actual data written does not matter and data read will be undefined typically all ones Base 3 Write Writing any data to this register starts ADC Conversion Base 4 Read and Write Reading starts ADC Conversion if CHGCHV bit is high as defined in Command Register Base 0 any write operation forces DACO and DAC1 to output zero volts but does not clear internal DAC data registers Writing data to the DAC output registers high bytes Base 9 or Base B will re enable the DAC outputs Base 5 Write Performs the same operation as described for Base 4 write operation Manual MA1216E D2a Page 6 3 A1216E Manual A D Registers A D data are in true offset binary form or two s complement by jumper selection and are latched in the A D registers at the end of each conversion The data are read at base address 6 and base address 7 in low byte high byte sequence The data are available until the end of the next A D conversion If the two s complement register format is enabled an option for bipolar ranges then the data format of the DAC analog output registers will also chan
67. tal circuits by their very nature generate considerable high frequency noise as they rapidly change state Manual MA1216E D2a Page 7 1 A1216E Manual Ground Loops AC noise and DC offset can be added in series with a grounded signal source 1f the source ground is at a different potential than the A D s analog ground If there is an ohmic resistance between the source ground and the A D s ground the resultant current flow causes a voltage to be developed and a ground loop exists Ifthe signal is measured in a single ended mode that voltage is added to the source signal thereby creating an error The best way to avoid ground loop errors is to use good wiring practice as described above If this is not possible use of a differential measurement mode will minimize errors External Noise Voltages can be introduced onto signal lines via electro magnetic radiation and or capacitive coupling If the differential measurement mode is used that noise appears in phase on both the high and low lines and the common mode rejection capability of this measurement mode will severely attenuate the noise In extreme cases twisted pair and or shielding will also reduce the noise problem Input Range and Resolution Specifications Resolution of an A D converter is usually specified in number of bits 1 e 8 bits 12 bits etc Input range is specified in volts i e 0 5V 10 V 20 mV etc To determine the voltage resolution of an A D converter simply d
68. tiplexer card and is designed to provide simple access to the full functionality of that MDM s specific sub multiplexer These drivers are provided in the form of OBJ object files that can be linked to any language that supports the Pascal calling convention QuickBASIC VisualBASIC for DOS C C Fortran Assembler and Pascal just to name a few Each object file is named the same as the sub multiplexer s six character model number The MDM file is used in conjunction with the Card Driver Module CDM to provide seamless access to any A D card assuming that the A D card supports use of the specific sub multiplexer without re programming In effect the non A D card specific functionality of the CDM system is retained when using the Multiplexer Driver Modules This allows your code to be written to take advantage of a sub multiplexer s advanced features without worrying about A D card compatibility By changing the link statement during program creation to reflect which CDM is desired the same source code can be re used for any CDM supported A D card Functionality provided by the MDM is specific to the sub multiplexer in question except for a few basic and general functions as follows int SetBaseAddress unsigned integer address This routine tells the MDM which address to use when calling the CDM in order to program the A D card When this routine is used it s not necessary to call each function in the MDM with a base address parameter
69. tor is suggested if serious overvoltage or static problems exist As an alternative a factory installed special multiplexer will extend overvoltage protection further The channel input configuration is jumper selectable on the card providing a choice between sixteen single ended channels or eight differential channels In the latter case common mode rejection ratio is a minimum 80 dB and common mode voltage range is 12V Inputs are amplified by an instrumentation amplifier with a combination of switch selectable gains of 1 or 2 and software selectable gains of 1000 100 10 and 1 to provide voltage ranges of 0 005 0 01 0 05 0 1 0 5 1 5 and 10 volts bipolar and 0 01 0 1 1 and 10 volts unipolar gain switch must be set to x2 A1216Euses an industry standard 12 bit successive approximation analog to digital converter A D with a sample and hold amplifier input Under ideal conditions a throughput of 120 000 conversions per second is possible A D conversions may be initiated in any one of three ways a by software command b by on board programmable timer or c by direct external trigger In turn completion of A D conversion may be determined by either of two software selectable methods a by polling for end of BUSY or b by end of BUSY interrupt Input System Expansion The card can be used with up to sixteen external analog input expansion cards but consult the factory if more than eight expansion cards are to be
70. ual MA1216E D2a Page B 1 A1216E Manual A1216E Auxiliary Connector Pin Assignments The 40 pin IDC connector on the A1216E board surface carries the auxiliary 8255 Digital Input Output lines and they appear on a second 37 pin rear panel connector with the following pinouts 1 Ooo 2 _ j ING Ums j j U O I 3 5 PB7 DigitalvOPotB Bit7__ I 4 7 PBG DisitalVOPortB Bit6 Ss 9 PBS Digital O Port B Bit5 I 6 1 PB4 DigitalVOPotB Bit4__ 8 15 PB DigitalWOPorB Bit I 9 17 PBI DisitalWOPortB Bitl GND Ground Unused O 2 6 Ls as A SA GND GND GND n lt GND Q lt GND PC7 PC6 PCS Ground Unused Ground Unused Ground 5 VDC Output Ground 5 VDC Output Ground Digital I O Port C Bit 7 Digital I O Port C Bit 6 Digital I O Port C Bit 5 Digital VO Port A Bit 1 Table B 2 A1216E Auxiliary Connector Pin Assignments The 37 pin female mating connector can be a Cannon DC 37S for soldered connections or insulation displacement flat cable types such as AMP 745242 1 may be used The wiring may be directly from the signal sources or may be on ribbon cable Page B 2 Manual MA1216E D2a A1216E to First Multiplexer Set Cable Adapter Assembly If you are using an A1216E with an external multiplexer such as an AIM 16MP a special cable adapter may be used The cable adapter will allow use of the lower eight channels of the A1216E for up to elght A
71. und will not be at exactly the same voltage as the computer ground where the A1216E is because the two grounds are connected through ground returns of the equipment and the building wiring The difference between the ground voltages forms a common mode voltage i e a voltage common to both inputs that a differential input rejects up to a certain limit If you have a combination of floating and ground referred signal sources use the differential configuration For the ground referred signals connect a jumper between the low input and the low level ground at pins 28 or 29 The jumper connected between the low input and the low level ground effectively turns that differential input into a single ended input It s important to understand the difference between input types how to use them effectively and how to avoid ground loops Misuse of inputs is the most common difficulty that users experience in applying and obtaining the best performance from data acquisition systems Comments on Noise Interference Noise is generally introduced into analog measurements from two sources a ground loops and b external noise In both cases use of good wiring practice will reduce and sometimes eliminate the noise A key point with regard to ground or return wiring is that in an analog digital system digital circuits should have a separate ground system from analog circuits with only a single common point The reason for separate ground busses is that digi
72. used The A1216E does not support the programmable gain capability of the AIM 16P and requires either that the AIM 16P must be operated in manual gain mode or that the AIM 16MP manual gain only version be used Each AIM 16MP card provides capability for 16 differential inputs and thus there can be up to a maximum of 256 inputs per combination of AIM 16MPs and A1216E Appendix B contains the information on the required cables and adapters Manual MA1216E D2a Page 1 1 A1216E Manual Discrete Digital I O Four bits of TTL CMOS compatible digital input capability are provided at the mounting panel connector Twenty four additional digital I O bits are available at the auxiliary connector on the board A ribbon cable extends the auxiliary connector to a 37 pin connector on an auxiliary backplate that can be installed next to the main rear connector Digital inputs IPO and IP2 have dual uses Input IPO provides an external trigger for the A D Input IP2 is also the gate input for Counter Timer 0 Note that the use of Counter 0 prevents use of IP2 for any other function Four bits of digital output are available with LSTTL logic level load drive capability Discrete outputs OPO through OP3 provide multiplexer addressing for analog input expansion card use as described in the INPUT SYSTEM EXPANSION section or as separate digital outputs Additionally OPO through OP3 can be individually software configured for use as additional TTL CMOS compatible

A1216E Manual - ACCES I/O Products, Inc.

Contents

Download Pdf Manuals

Related Search

Related Contents