PC-81A Manual - EAGLE Technology
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1. ie R 20200 1997 EAGLE TECHNOLOGY 5 i 1 db 95 2 USE FOR PARALLEL INTERCONNECTION QF PG p bar mob gt Ho00000000000000000 90909099090000000000 9 Ho 00 0 00 oo oo 0000000000 3829s9939293 95525 6 IMn000000000000000000000000 212. digital output lines and 273 PC 81 s Note that with sufficient digital output lines the sub multiplexed technique can be extended far further than this limited only by accuracy constraints These constraints are fully described in appendix B PC 81A Package The PC 81A package consists of LEX PC 81A Analog Input Expander Card Mounting kit PC 81A User s Manual EDR Developers Toolkit User Manual 3 diskette A DB37 type male connector and cover One 37 diskette containing the PC 81A drivers and demonstration software If any of the items is missing contact your dealer immediately specifying which components are missing Chapter 1 Installation There are four aspects of the PC 81A that must be configured Refer to figure 2 1 1 The Multiplexer Address Selection This address determines which of the four onboard multiplexers 16 input channels are accessed Address 0 to are used for this purpose The inputs to the multiplexers are the 64 input channels CHO to CH63 and their 4 outputs are VO to V3 For a differential configuration CH32 acts as the return for CHO CH33 acts as the return for CH1 etc In differential configuration output V2 is the return for VO and V3 is the return for V1 1 2 The Card Address Selection This address determines which PC 81A card is accessed This can be set by the 8 way DIP switch found onboard The address range in parallel mode is from PC 81A 0 to PC 81A 25
3. of a data acquisition system will result in measurement errors In the case of the PC 81A and multiplexers in general it is the effect of the leakage current which is by far the most significant Cause This is especially the case for large numbers of multiplexers 7 1 Multiplexer leakage current All multiplexers have some leakage current For most multiplexers including those uesd on the PC 81A this is strongly temperature dependant typically doubling every10 C For this reason leakage currents are specified both at 25 C and at 70 C For the PC 81A and almost all multiplexers used on A D cards maximum current at 25 is 1nA 7 2 Parallel operation For parallel operation the error due to leakage can be calculated as follows Verr Nm 2 Rm Rs Im where Verr is the error voltage due to leakage current Nm is the number of PC 81 A s Rm is the PC 81A s ON resistance Hs is the source resistance Im is the PC 81A leakage current Note that this calculation assumes that the A D card contains a similar multiplexer to that in the PC 81A This is almost always the case 7 3 Sub multiplexed mode operation For sub multiplexed mode operation the error due to leakage can be calculated as follows Verr 1 1 Rm 2 N1Rs Im where Verr is the error voltage due to leakage current N1 is the number of layers of multiplexers including the multiplexer on the host A D card Rm is the PC 81A s ON re
4. type of board present at a specified I O address Changes the board type attached to a board handle Set the IRQ level EDR will use for the interrupt ID specified 14 An example of the using external trigger interrupt function is shown below This program is also found in the EDR Driver Toolkit Simple external interrupt demo Installs an ISR to count external interrupt inputs from the board Main functions demonstrated EDR InstallBoardISR EDR_MaskBoardIRQ EDR EnableInterrupt EDR UninstallBoardISR ig EDR ResetInterrupt Boards supported All boards with an external interrupt input c 1994 David Tinker RL include edr h driver functions include lt stdio h gt include lt stdlib h gt include lt conio h gt include ctype h include lt string h gt include lt dos h gt volatile int bh our board handle volatile unsigned long icount 0 interrupts processed void printerror int r displays error msg and exits void quit int c release our board handle and exit void interrupt ISR our interrupt handler void main int argc char argv int baseaddr int boardtype int i j k ch char s 80 printf EXTINT External interrupt demo n n if argc 2 sscanf argv 1 x amp baseaddr lse baseaddr 0x300 first get a board handle to use bh EDR AllocBoardHandle if bh
5. written in and displays finish this later 3 2 PC 81A Settling Time As may be seen from the above the major software consideration in using the PC 81A is the seetling time When using only an A D card the settling time of the cards s internal multiplexer is included in the card s conversion time and hence does not require any attention If a PC 81A is used however the settling time of the multiplexers on the PC81A must be taken into account This is normally done by a timing loop although certain A D cards have timers on board which could be used for this purpose The use of a timing loop is shown in the demonstration program finish this later The actual settling time of the PC 81A is dependant on several factors namely 3 Cable length The longer the cable between the PC 81A and the A D host card the longer the settling time 3 Source resistance The effect of the cable is mainly to increase capacitance which must be charged from the voltage to be measured The higher the source impedance the longer this will take PC 81A configuration When using multiple PC 81A s the way in which they connected significantly effects the settling time In general the settling time of sub multiplexed PC 81 A s is significantly lower than that of parallel PC 81A s The following figures may be taken as general guidelines for applications which use relatively short cables less than 1 metre in lengt
6. 5 Address lines A4 to A11 are used for this purpose See figure 1 below DIP SWITCH DIP SWITCH POSITION PC 81A 1 dO 8 oF o 1 AND 2 8 E BUER E AND 3 AND 3 6 Figure 1 81 8 DIP switch for address setting 1 3 The A D Card Input Channel Selection Most A D Multifunction Cards have 16 input channels As the PC 81A has only 4 output channels normally 12 of the A D cards input channels would not be used The PC 81A has four A D Card Input Channel Selection headers labelled BOARD 0 to 3 Jumpers on BOARD 0 inserted direct the four mutiplexer outputs to V0 V1 V2 amp V3 Jumpers on BOARD 1 inserted direct the four mutiplexer outputs to V4 V5 V6 V7 Jumpers on BOARD 2 inserted direct the four mutiplexer outputs to V8 V9 V10 amp V11 Jumpers on BOARD inserted direct the four mutiplexer outputs to V12 V13 V14 amp V15 1 4 The Power Supply The PC 81A operates on 12V 12V amp 5V power supplies These can usually be obtained from the host A D card However to allow for those cards which do not supply 5V the PC 81A has an internal provision for the generation of this voltage from the 12V supply Note that this considerably increases the power consumption of the PC 81A The internal 5V is enabled by inserting jumpers H 2 amp H 3 NOTE THESE JUMPERS MUST NOT BE INSERTED IF THE HOST CARD SUPPLIES 45V Certain h
7. NES MULTIPLEXER QUT H16 RET T ao i 4 2 A2 LEID Re sk ER eet NAG H RET v n AGNO amp R1 LINK HEADER 2K2 Hi 12V TO 5V INPUT DIP SHITCH COMPARITOR CIRCUIT ANALOG LINK HEADERS CHANNELS AGND Figure 2 PC 81A Block Diagram CHAPTER 2 Interconnections The PC 81A can be connected to any analog input card which has at least four preferably sixteen A D channels and twelve TTL output lines 2 1 Connections to the analog card All data transfers to the host analog card are channelled via a screened cable from the PC 81A s User Connector 2 2 The User Connector The PC 81A interfaces to the external world via a 37 way D type male connector This connector acommodates the following signals 16 separate analog output signals VO V15 12 address lines AO A11 5V 12V 12V AGND amp Figure 3 PC 81A User Connector as seen from the front 0837RH Figure 3 graphically shows the connector together with their pin assignments Note that the pin connections refer to the pin numbers of the connector when looking into the connector from the front The square pad of the pcb component at location P1 represents 1 Also note that the pin numbers are embossed on the connector itself but please note that sometimes the connector manufacturers do make mistakes 2 3 The 64 Analog Input Ground and Aux Screw terminals Each of the sixty fo
8. PC 81A Analog Input Expander Card User s Manual All rights reserved No part of this Publication may be copied stored in a retrieval system or transmitted in any form by any means electronic mechanical by photocopying recording or otherwise in whole or in part without prior written permission from the Publishers First Edition April 1997 April 1997 Printing Information furnished in this manual is believed to be accurate and reliable however no responsibility is assumed for its use nor for any infringements of patents or other rights of third parties which may result from its use IBM IBM PC XT AT and IBM PS 2 are trademarks of International Business Machine Corporation MicroSoft and MSDOS are trademarks of MicroSoft Corporation Copyright 1997 Eagle Technology Table of Contents Page Introduction 4 Chapter 1 Installation 6 1 The Multiplexer Address Selection 6 2 The Card Address Selection 6 3 The A D Card Input Channel Selection 6 4 The Power Supply 6 5 Installation 7 Chapter 2 Interconnections 8 2 1 Connections to the Analog Card 8 2 2 the User Connector 8 2 4 The 64 Analog Input Ground and Auxilliary Screw terminals 9 Chapter 3 Sofware Guide 10 3 1 Obtaining a sample 10 3 2 PC 81A Settling Time 10 Chapter 5 Repair Service 16 Chapter 6 Hardware Specifications 17 Chapter 7 Error Analysis 18 7 1 Multiplexer leakage current 18 7 2 Parallel operation 18 7 3 Sub multiplexed mode oper
9. al I O port on the PC 63C This function determines whether any one of the reed relays is ON OFF Installs an ISR for the specified hardware interrupt request Removes an interrupt service routine that was installed with EDR InstalllSR Installs an ISR for a particular type of interrupt installed on the PC 63C Removes an interrupt service routine that was installed with EDR InstallBoardlSR Masks or unmasks a particular IRQ level Masks or unmasks a particular board interrupt Enables disables a specified interrupt on hte PC 63C Resets an interrupt latch on the PC 63C and sends an EOI command to one of the PCs interrupt controllers on completion of the interrupt Allocates a new board handle to the PC 63C If no board handles are available then a 0 is returned This is particularly useful is multiple PC 63C are present in the same computer Releases a board handle allocated to the PC 63C making it available to any other PC card Initialises a board and allocates a board handle to it Diplays a dialog box that allows the user to manually configure the driver for the Board in the computer Function writes configuration information to a file for later loading with EDR LoadConfiguration Loads details of the Cards configuration from the file created by EDR SaveConfiguration Restores factory default configuration for a baord attached to a handle Checks if any board initialised with EDR is using the specified I O address Tries to determine the
10. ation 18 Chapter 8 PC 26 30AT Considerations 19 Appendix A PCB Layout Diagram 20 Introduction The PC 81A is an analog input expander card It has been designed to allow extra analog input channels to be added to virtually any analog input card In order for it to operate it requires the following a ae The existing analog input card must have at least two differential or four single ended analog inputs There must be at least four digital output lines available These digital output lines need not be a part of the analog input card but can be from any other card or if desired from a mechanical switch Users of PC XT AT machines can easily use a low cost PC 36A B C parallel interface card if their analog input cards do not have digital outputs available A power supply must be available This must have voltages of 12V to 15V and 5V available If no 5V is available then it can be obtained from the 12V to 15V by setting two jumpers on the PC 81A Typical applications oe Features Complex Process Control Laboratory Automation Energy Management Product Testing Four 16 channel multiplexers giving 64 single ended or 32 differential input channels Each PC 81A card can be individually addressed card 0 to card 255 by setting an 8way dip switch There are four analog outputs per PC 81A one for each multiplexer As most analog input cards have sixteen input channels any four of
11. f j 0 printerror j EDR MaskBoardIRQ bh EDR INT EDR EnableInterrupt bh EDR _ 0 unmask the IRQ NT EXTINPUT 1 start generating ints display count until esc is pressed printf n do printf Slu interrupts have occured press esc to exit c icount 13 if kbhit ch getch else ch 0 while ch 27 printf undo interrupt stuff very important EDR EnableInterrupt bh EDR INT EXTINPUT 0 stop generating ints EDR MaskBoardIRQ bh EDR INT EXTINPUT 1 mask the IRQ EDR UninstallBoardISR bh EDR INT EXTINPUT remove our ISR release the board handle not necessary for DOS EDR FreeBoardHandle bh void interrupt ISR this gets called for every external interrupt icount _ Interrupt bh EDR_INT_EXTINPUT signal interrupt complete void printerror int r displays error msg and exits char s 80 EDR_StrError r s convert error number into a string printf Ss n s quit 1 void quit int c release our board handle and exit EDR FreeBoardHandle bh exit c 16 Chapter 5 Repair Service The PC 81A is guaranteed for a period of 1 year If the board is faulty within this period we will gladly repair it free of charge provided t
12. h For a single PC 81A approximately 5uS 3 For multiple PC 81A s in sub multiplexed mode add 505 for each layer of PC 81A s 3 For multiple PC 81A s in parallel mode add 205 for each PC 81A Chapter 4 Driver Software Full driver software is supplied with the PC 63C package Full details are explained in the EDR Software developers kit User Manual A summary of what these drivers consist of are explained below Both DOS and Windows Languages are supported They are DOS Languages Borland C C Version 3 1 or 4 0 Microsoft C C Version 6 0 or 7 0 Borland Pascal Turbo Pascal Version 6 0 or 7 0 Microsoft QuickBasic Version 4 5 National Instruments LabWindows Version 2 0 Windows Languages Borland C C 3 1 or 4 0 Microsoft C C 6 0 or 7 0 Borland Pascal Turbo Pascal Version 6 0 or 7 0 4 1 Board Handles All EDR functions used above require a board handle as the first parameter The board handle defines which board is affected by the function call Using this method has several advantages For example there is no need for a select board function working with parallel boards is much easier different applications using the EDR at the same time will not conflict with each other Board handle are integers obtained by calling EDR AllocBoardHandle see 7 2 of EDR Developers Toolkit Once allocated a board handle must be initialised to the PC 63C before it can be accessed this is achieved by calli
13. hat the maximum specifications was not exceeded lf any burn t tracks are seen on the PC 81A Card or any of the multiplexers are blown the warranty will be void A repair charge will then be levied if the user requires the board to be repaired Qur repair service centre will be available to repair our products even after the 1 year warranty A reasonable service fee will be levied which usually covers the cost of the components that are faulty and the labour cost per hour or part thereof Chapter 6 Specifications Number of channels Resistance input to output Input capacitance Output capacitance Leakage current inputs Leakage currrent outputs Settling time Minimum host impedance Digital inputs Power supply current 12V Power supply current 12V Power supply current 5V Power supply range 12V Power supply range 12V Power supply range 5V 64 Single ended 32 Differential 2K Ohm channel ON 100M Ohm channel OFF 20pF max 20pF max 5nA max 25 C 100nA max 70 C 5nA max 25 C 100nA max 70 C 1 5uS max with a 10 Ohm source impedance and a 5OpF load 100M Ohm TTL compatible 100uA max leakage current 4mA max with internal 5V power supply disabled and 10mA max with internal 5V power supply enabled 4mA max 500 11 5V to 15V 11 5V to 15V 4 5V to 5 5V Chapter 7 Error Analysis Any extra components in the signal path
14. ng EDR InitBoard or EDR InitBoardType see 7 5 of EDR manual with the base address or EDR loadConfiguration see section 7 8 of EDR manual EDR InitBoard will attempt to detect the PC63C at the base address specified 4 2 Interrupt functions Since the external trigger line on the PC 63C is connected to a hardware interrupt an ISR can be installed using the EDR driver functions provided These functions are only callable from C C or Borland Turbo Pascal 4 3 Quick Function Reference The PC 63C Enhanced Reed Relay Board utilises the following functions calls contained in the EDR driver developers toolkit They are Function Name EDR DIOPortOutput EDR_DIOPortInput EDR_DIOLineOutput EDR_DIOLineOutput EDR InstalllSR EDR UninstalllSR EDR InstallBoardlSR EDR UninstallBoardlSR EDR MaskIRQ EDR_MaskBoardIRQ EDR Enablelnterrupt EDR Resetlnterrupt EDR AllocBoardHandle EDR FreeBoardHandle EDR InitBoardType EDR ConfigDialog EDR SaveConfiguration EDR LoadConfiguration EDR RestoreDefaults EDR IsBaseAddresslInUse EDR DetectBoard EDR SetBoardType EDR SetlRQLevel Description Writes a byte of data to the PC63C I O port Reads a byte of data from the PC 63C I O Port If the port is an output port then the last value written to the port is returned Changes a single line bit on the PC63C 1 0 port This in turn switches one the reed relays ON OFF on the PC 63C Obtains the status of a single line in a digit
15. ost A D cards do not have separate digital and analog ground For these cards jumper H1 can be inserted This connects the two together It is not normally required and should be inserted only when absolutely necessary as it s use results in an increase in noise levels 1 5 Installation A Mounting kit is provided for this purpose For single PC 81A installations fix four double ended female hex stand offs to each of mounting holes on the card and there after the card to the mounting cabinet with the screws provided It is not necessary to solder any male and or female headers to location H4 on the PC 81A For Piggy backed Parallel PC 81A installations first decide how many PC 81A s are going to be used for your particular installation This can be determined by how many analog channels you require You then need to work out a pattern for mounting the interconnecting single row headers to the top and or bottom of each PC 81A by soldering It is advisable to mount the female header always on the bottom of any PC 81A so that if the Piggy backed cards are ever seperated they can still be mounted normally First solder a female single row header to the PC 81A to be mounted above then plug the single row male header fully into that female By fixing four double ended female hex stand offs to each of mounting holes on the lower PC 81A with four male female hex stand offs and attaching the upper PC 81A by carefully lining u
16. p the the other end of the male header with the appropriate mounting holes of pcb location H4 on the PC 81A below the male header can now be soldered into place The two PC 81A s are correctly spaced by these stand offs After soldering cut off the protruding pins Continue with this procedure until all of the proposed PC 81A s are prepared Remember to alternate rows with regards to mounting male female headers to pcb location H4 Now connect all analog input wires to the lower PC 81A Set any jumpers and or dip switches as necessary before mounting the next PC 81A above using another four male femal hex stand offs Repeat this procedure until all of the cards are mounted The lower PC 81A is secured to your mounting cabinet box by using four screws supplied The upper most PC 81A is also attached by four screws NB This Piggy back procedure can performed by the manufacturer if requested This method of Parallel Interconnection vastly reduces the space needed for mounting the PC 81A s and the amount of wiring necessary to control them A cable from the A D card in the host PC with only a single DB 37 FM connector to all the PC 81A s is now only necessary BOARD 0 MULTIPLEXER H8 1 ae 28 aa ms A 1 BOARD 1 7 reet CH32 HO RET T BOARD i H OUTPUT SELECT d 1 ANALOG HEADERS T aes 7 DES CHANNELS FOR CH47 CARD NA TTL CHANNEL INPUT SELECTION ADDRESS LI
17. sistance Hs is the source resistance Im is the PC 81A leakage current Note that this calculation assumes that the A D card contains a similar multiplexer to that in the PC 81A and that this calculation uses the number of layers of multiplexers NOT the number of multiplexers For example in the the figure still not finished N1 would be 3 Note also that because the error in the case of sub multiplexed mode operation is dependant on the number of layers rather than the number of multiplexers errors for sub multiplexed mode operation are considerably lower if large numbers of channels are used Chapter 8 PC 26 30AT Considerations For users of the older PC 26 30AT data acquisition cards certain special considerations apply PC 26 30AT cards have built in termination resistors in order to prevent errors due to open inputs These termination resistors must be removed to allow operation in conjunction with a PC 81A The components in question are the 22K Ohm resistor arrays R9 and R10 and the discrete 22K Ohm resistors R6 and R7 We recommend removal by simply cutting the leads of these components on the component side of the board Attempting to de solder the components is NOT recommended unless you are an experienced technician with the correct equipment for the job 20 Appendix A PC 81A PCB Layout Diagram sn u o o o o o o o o o o o o o o o j ow 38 E E i 2 E 4
18. these can be selected on the PC 81A by using the on board jumpers Multiple PC 81A s can be interconnected in a multitude of fashions The two major techniques are Parallel Interconnection and Sub Multiplexed Interconnection For simplicity with regards to cabling when using Parallel Interconnection any number of PC 81A s can be piggy backed ie one on top of the other by the adding male and or female headers supplied in the mounting kit to pcb location H4 Parallel Interconnection This technique allows the maximum possible number of channesl with the lowest possible number of PC 81 s For every four single ended or two differential inputs on the host card you can have 64 single ended or 32 differential inputs with 4 digital output lines and 1 PC 81 1024 single ended or 512 differential inputs with 8 digital output lines and 16 PC 81 s 16384 single ended or 8192 differential inputs with 12 digital output lines and 256 PC 81 s Sub multiplexed interconnection This technique requires a larger number of PC 81 s for a given channel density but has less effect on accuracy for large numbers of channels For every four single ended or two differential inputs on the host card you can have 64 single ended or 32 differential inputs with 4 digital output lines and 1 PC 81 1024 single ended or 512 differential inputs with 8 digital output lines and 17 PC 81 s 16384 single ended or 8192 differential inputs with 12
19. this should never happen with DOS printf No free board handles n exit 1 ask if user wants auto detection printf Autodetect board type only works with no cables attached Y N 27 do i toupper getch while i 2 Y amp amp i 2 N printf cNn 1 if i Y look for board at specified base address i EDR InitBoard bh baseaddr if 1 lt 0 printerror i else ask user for type of installed board printf Choose board type from the following list n for i l i lt NUMBOARDTYPES i sprintf s 02d i EDR StrBoardType i s 3 for strlen s lt 14 strcat s 15 printf s s printf nType the number of the board installed enter to exit gets s i atoi s if i quit 1 i EDR InitBoardType bh baseaddr i if 1 lt 0 printerror i let the user chose the base address EDR ConfigDialog bh 1 1 1 1 1 1 1 copy the board type into a var EDR GetBase bh amp baseaddr EDR GetBoardType bh amp boardtype make sure this board has an external interrupt input if EDR ValidInterruptID boardtype EDR INT EXTINPUT printf This board does not have an external interrupt input n quit 1 install our ISR for first external interrupt the second would be EDR_INT_EXTINPUT 1 and so on jeEDR InstallBoardISR bh EDR INT EXTINPUT ISR i
20. ur analog inputs is multiplexed and redirected via the BOARD 0 3 headers to the User Connector The Auxilliary Screw terminal connector includes 0 A11 VO and AGND and 5V 12V 12V DGND spuueya mdu pwy 150 8181 o eaad 5 220814 spoenueqo indu Sojeue A V oj quo uor CT 916 29 0 UuT8 2d T UTR 4 5 16a uno Wwilore Mi sindino 7911210 0 auva 957 1560 oereg 155 UMOYS 8 19 2 4 dumu fo asn ou ez 10 2 5 2 Sub Multiplexed Interconnection PC 61A PC 81A pereen tm Tala LLLI ERE arem ttam TTL DIGITAL OUTPUTS Figure 6 Sub Multiplexed Interconnection Using only four A D Host Card analog input channels 11 Chapter 3 Software Guide This chapter discusses the software considerations necessary for A D host cards which use the PC 81A 3 1 Obtaining an A D Sample The steps required to obtain an A D sample are as follows Set the A D card input channel Il Set the PC 81A channel Wait for the PC 81A to settle IV Trigger the A D converter in the A D host card V Wait for the A D conversion to complete VI Read in the result A demonstration program PC 81A supplied on the disk included with the PC 81A shows how this is done This program is
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