MSI-P412 User Manual (Adobe Acrobat Format)
Contents
1. 4 MSB s of HI Byte 90 Print CHO CH4 Linefeed CH4 CH7 100 IF 1 3 OR I 7 THEN PRINT HEX X ELSE PRINT HEX X 110 NEXT 120 PRINT 130 GOTO 30 Go Again G Example C Program Sequence For a simple C program illustration using software polling of the device status consider a case with the following parameters and events 1 A base address for the card of 7FFOH insert jumper A15 2 Read A D channel 9 input to U7 in the 5V unipolar mode and store the result in CH_9_INPUT 3 Read A D channel 27 input to U9 in the 10V bipolar mode and store the result in CH_27_INPUT A simple program sequence for this operation is Constant declarations define base_address 0x7ff0 card base address define control byte 5 0x40 control byte for 5V range define control_byte_5B 0x48 control byte for 5V range define control byte 10 0x50 control byte for 10V range define control byte 10B 0x58 control byte for 10V range define delay_count 1000 delay count for converter time out Page 12 MSI P412 User Manual Memory assignments int A_D_value CH 9 INPUT CH 27 INPUT Routine to input A D channel CHAN 0 31 for control byte C BYTE and returns 0 on a converter time out error Stores converted value in A D value int input A D int CHAN int C BYTE int converter_error a i ch_group if 0 lt CHAN amp amp CHAN lt 8 ch group 0 e2. QO00000000 oDD00000001 cof C o n n o Ge a q a v A noe n n SS SE ERE ES ES u uz cu nnnnnns onn snn ses nnnunn BER MICROCOMPUTER SYSTEMS INC o D000000 a a Na 1814 RYDER DR BATON ROUGE LA af D AA 504 769 2154 OW p0o0000 Figure 2 MSI P412 card outline Page 5 MSI P412 User Manual B Card Addressing The card address is set by installing appropriate jumpers on JP1 pins 1 thru 24 as shown in Fig 3 An uninstalled jumper for a given address bit sets the bit to 1 true and an installed jumper sets the bit to O false Addresses A4 thru A15 are jumper selectable for defining the base address of the card from OOOOH to FFFOH on integral 10H boundaries where H denotes a hexadecimal number To assign a base address of 3040H for example install jumpers JP1 A4 JP1 A5 and JP1 A7 thru JP1 A13 Pins 25 thru 34 are used to configure the interrupt connections if interrupts are used as described in the Section II C The MAX197 converters each have two registers for performing data conversions a control output register C and a input data register I A third register implemented on the card for denoting interrupt status is called the status register The addresses of the control input data C I and status for each channel is given in Table 1 The functions of the control the input data hi and lo bytes and status registers are described in the Section III me zae2e Zaos natnn
3. of the control register In the case of channels 0 7 addresses base O and base 1 respectively are read D Input Data Format Unipolar Mode the output data format is binary In this case O volts input yields OOOH where H denotes a hexadecimal number The value increases linearly from OOOH to FFFH with increasing input voltage A FS input full scale 5V or 10V ranges gives FFFH Bipolar Mode the output data format is twos complement binary In this case a FS input 5V or 10V ranges yields 800H The value increases linearly from 800H toward FFFH as the input voltage changes from FS toward 0 volts Page 10 MSI P412 User Manual At 0 volts input in the ideal case the value is OOOH Again the value increases linearly from OOOH toward 7FFH as the input voltage changes from O toward FS volts The lo byte read bits DO thru D7 of the input data is the low byte BO thru B7 of the conversion result The hi byte read of the input data contains bits B8 thru B11 of the conversion result in bits DO thru D3 Bits D4 thru D7 contain all 0 s and all 1 s respectively for the unipolar and bipolar modes E Power Down Modes To save power the converters can be placed into a low power shutdown mode between conversions Two pro grammable power down modes are available Select STDBYPD or FULLPD by programming PDO and PD1 in the control register When software power down is asserted it becomes effective only after the end of
4. 20 Ch23 P2 2 Ch31 P2 20 Note Pins P1 17 P1 18 P2 17 amp P2 18 are connected to 5V E Using the MSI P910 and Current Inputs A schematic of the MSI P910 terminal card is given in the Appendix The card provides terminal strips for connecting field wiring for 16 channels 8 channels for the MSI P9 10 8 using a 34 pin flat cable Pads are also included for adding 250 Ohm precision resistors for 0 20 mA or 4 20 mA inputs The 0 5V input range is used in these cases Page 8 MSI P412 User Manual lll PROGRAMMING Performing data conversions involves a write operation to the control register of the appropriate MAX197 which selects the mux channel and configures the input mode The data is then read lo byte and hi byte when the conversion has been completed A Control Register Format The control register is an 8 bit write only register that selects the mux channel and mode of the converter The format is D7 MSB D6 D5 D4 D3 D2 D1 DO LSB PD1 PDO ACQMOD RNG BIP A2 A1 AO where PD1 PDO select the clock and power down mode Table 3 ACQMOD 0 internally controlled acquisition 1 externally controlled acquisition RNG selects the full scale voltage range Table 4 BIP selects unipolar or bipolar conversion mode Table 4 A2 A1 AO select the desired input channel 0 7 of the MAX197 Table 3 Clock and Power Down Selection PD1 PDO DEVICE MODE 0 0 Normal Operation Externa
5. MSI P412 ANALOG INPUT CARD USER MANUAL PC 104 Embedded Industrial Analog I O Series Microcomputer Systems Inc 1814 Ryder Drive Baton Rouge LA 70808 Ph 225 769 2154 Fax 225 769 2155 Email staff microcomputersystems com http www microcomputersystems com CONTENTS INTRODUCTION 3 ll HARDWARE DESCRIPTION 5 A Card Configuration mod w moov D gt Card Addressing Interrupt Connections Connecting Inputs to P1 and P2 Using the MSI P910 and Current Inputs PROGRAMMING Control Register Format Performing a Conversion Reading the Data Register Input Data Formats Power Down Modes Example BASIC Program G Example C Program Sequence APPENDIX 14 Circuit Diagrams MSI P412 MSI P910 I INTRODUCTION The MSI P412 is a low cost high performance 12 bit analog input card designed for use with all PC 104 embedded systems Four models provide input capacities of 8 16 24 or 32 channels which operate from a single 5V supply Software programmable input ranges are 0 5V 0 10V t5V and 10V with a linearity of 1 2 LSB In addition the inputs are overvoltage tolerant to 16 5V and a fault condition on any channel will not effect the conversion result on the selected channel A block diagram of the card is shown below The card employs up to four MAX197 eight channel A D converters that incorporate a precision 2 5V reference source with buffer amp an internal 1 56 MHz clock and succ
6. being enabled only when an interrupt request is active The status is then checked to determine which interrupt is active as described in Section III 3 Pin 32 of JP1 1 KOhm pull down resistor is used to properly terminate the interrupt line selected in step 1 This pin should be jumpered to the interrupt line on only one card in the system Page 7 MSI P412 User Manual D Connecting Inputs to P1 and P2 Inputs are interconnected to the card via P1 and P2 using 34 pin flat cable connectors Pin assignments are given in Table 2 Table 2 Pin assignments for Input Connectors P1 and P2 Input Pin Input Pin Input Pin Input Pin Ch0 P1 15 Ch8 P1 33 Ch 16 P2 15 Ch 24 P2 33 ChO P1 16 Ch8 P1 34 Ch 16 P2 16 Ch24 P2 34 Chi P1 13 Ch9 P1 31 Ch17 P2 13 Ch 25 P2 31 Ch 1 P1 14 Ch9 P1 32 Ch 17 P2 14 Ch25 P2 32 Ch 2 P1 11 Ch 10 P1 29 Ch 18 P2 11 Ch 26 P2 29 Ch2 P1 12 Ch10 P1 30 Ch18 P2 12 Ch 26 P2 30 Ch 3 P1 9 Ch11 P1 27 Ch19 P2 9 Ch27 P2 27 Ch3 P1 10 Ch11 P1 28 Ch 19 P2 10 Ch27 P2 28 Ch4 P1 7 Ch12 P1 25 Ch 20 P2 7 Ch 28 P2 25 Ch4 P1 8 Ch12 P1 26 Ch20 P2 8 Ch28 P2 26 Ch5 P1 5 Ch 13 P1 23 Ch21 P2 5 Ch 29 P2 23 Ch5 P1 6 Ch13 P1 24 Ch21 P2 6 Ch29 P2 24 Ch6 P1 3 Ch 14 P1 21 Ch 22 P2 3 Ch30 P2 21 Ch6 P1 4 Ch14 P1 22 Ch22 P2 4 Ch30 P2 22 Ch7 Pt 1 Ch 15 P1 19 Ch 23 P2 1 Ch31 P2 19 Ch7 P1 2 Ch15 P1
7. conversion In both power down modes the interface remains active and conversion results may be read Input overvoltage protec tion is active The converter returns to normal operation on the first write to the control register In STDBYPD each device typically consumes 700uA and in FULLPD 120 uA maximum The converter voltage reference remains active in STDBYPD This is a DC power state that does not degrade after power down of any duration and any sampling rate can be used without regard to start up delays In FULLPD however start up delays will effect the conversion It is recom mended when using this mode that a STDBYPD power down cycle be performed prior to starting conversions to allow the reference voltage to stabilize Selecting STDBYPD on every conversion automatically shuts the MAX197 down after each conversion without requiring any start up time on the next conversion Page 11 MSI P412 User Manual F Example BASIC Program A simple BASIC program that inputs continually inputs channels 0 thru 7 for the 5V unipolar mode and lists the results to the console is given below 10 BASEADDR amp H300 insert jumpers A4 thru A7 A10 thru A15 20 CBYTE amp H40 Control Byte for 5V Unipolar Mode 30 FOR I 0TO7 40 OUT BASEADDR CBYTE I Write Control Byte 50 WHILE INP BASEADDR 8 AND 1 1 WEND Test Status 60 X INP BASEADDR Read LO Byte 70 Y INP BASEADDR 1 Read HI Byte 80 X X 256 Y AND amp HF Mask off
8. environments Page 4 MSI P412 User Manual ll HARDWARE DESCRIPTION A Card Configuration The MSI C412 card is a CMOS design using through hole and surface mounted devices The card configuration is shown in Figure 2 and a circuit diagram of the network is given in the Appendix The input signals for channels 0 thru 15 are applied to connector Pl and channels 16 thru 31 to P2 These signals are directed to the input terminals of A D converters U6 Ch 0 7 U7 Ch 8 15 U8 Ch 16 23 and U9 Ch 24 31 Jumper block JP1 is used for address selection Pins 1 thru 24 and interrupt configuration Pins 25 thru 34 as described below x MSI P412 cos EA g o gt el FSR amp o Ve O 4 zm e r N o7 i vu m F a mo v a T Erz Ta os or RE va FE cae VV Eco am Sl Fr al s C Je i o Ea co ee O eS fe e af Ek y6 4 vw an us SE qd 2 A Spe Mw rA EE _ geee SLIE SoG S e eg aed ee B 13 EB oun wemonzreoaoans lig Fa Bg x so vv OO 4 Hae ANNAN NAN mm Ls BONE eS a ae Soe a ere ee ee we L c6 cie be Sle n n 7 gt AN am Fa c3 53 S4 TE om DUNN S ITIL p R2 sf SE c E N
9. essive approximation and internal input track hold circuitry to convert the analog signal of each channel into a 12 bit digital signal Low span and offset errors result in no adjustments being required for these functions Typical total conversion times of 12 us gives a sample rate of 83 ksps for each group of eight channels yielding rates up to 332 ksps for 32 input channels A4 A15 JUMPERS Mee CH 0 7 34 PIN CONNECTOR PC 104 CH 0 15 BUS INTERFACE MASSY NETWORK CH 8 15 MSI P412 32 CONNECTOR PC 104 MAX197 BUS CH 16 23 INTERRUPT 34 PIN NETWORK CONNECTOR CH 16 31 PC 104 8 BIT STACKTHROUGH MAX197 INTERRUPT CH 24 31 JUMPERS Figure 1 Block Diagram of the MSI P412 32 Page 3 MSI P412 User Manual The card is I O mapped using 16 bit addressing to select the input channels and device status Option jumpers are provided by JP1 for specifying the card address A4 A15 and interrupt processing is provided for IRQ4 thru IRQ7 and IRQ9 using options jumpers as described in the next section The MSI P910 terminal card can be used to provide up to 16 analog inputs via terminal strips This card contains resistor sites for accommodating current inputs of 0 20 mA or 4 20 mA and includes surge protection for protecting against spurious voltages prevalent in harse or industrial
10. l Clock Mode 0 1 Normal Operation Internal Clock Mode 1 0 Standby Power down STBYPD clock unaffected 1 1 Full Power down FULLPD clock unaffected Table 4 Range and Polarity Selection BIP RNG INPUT RANGE V 0 0 0to5 0 1 0 to 10 1 0 5 1 1 10 Page 9 MSI P412 User Manual The card is designed to operate using the internal clock with PD1 0 and PDO 1 in normal operation The internally controlled acquisition ACQMOD 0 is nor mally used B Performing a Conversion Conversions are initiated with a write operation to the control register Table 1 which selects the mux channel of the desired MAX197 U6 Ch 0 7 U7 Ch 8 15 U8 Ch 16 23 or U9 Ch 24 31 and configures the device mode Selecting ACQMOD 0 in the control register selects the internal acquisition mode This causes the write to the control register to initiate the acquisition interval whose duration is internally timed Conversion starts when this six clock cycle acquisition interval ends Writing a new control byte during the conversion cycle will abort the conversion and start a new acquisition interval C Reading the Data Register Conversions are complete when the appropriate status bit Table 1 becomes 0 following a write to the control register Channels 0 7 U6 for example are ready when bit 0 at address base 8 is 0 The data can now be read at the appropriate lo and hi byte addresses for the lo and hi bytes of the channel selected A2 A1 AO
11. lse if 7 lt CHAN amp amp CHAN lt 16 ch_group 2 CHAN CHAN 8 else if 15 lt CHAN amp amp CHAN lt 24 ch_group 4 CHAN CHAN 16 else if 23 lt CHAN amp amp CHAN lt 32 ch_group 6 CHAN CHAN 24 outp base address ch group C BYTE CHAN write control byte if ch_group lt 1 a 1 else if ch_group lt 3 a 2 else if ch_group lt 5 a 4 else a 8 i 0 do i while inp base_address 8 amp a amp amp i lt delay_count if i delay_count converter_error 1 converter time out error else converter_error 0 A_D_value inp base address ch group get converter value A_D_value A_D_value inp base_address ch group 1 amp Oxf lt lt 8 return converter error void main void Input channel 9 for 5V range and store if no time_out error if tinput_A_D 9 control byte 5 CH_9_INPUT A_D_value Input channel 27 for 10V range and store if no time_out error if input A D 27 control_byte_10B CH_27_INPUT A_D_value Page 13 MSI P412 User Manual The function input A D int CHAN int C BYTE above is written in general terms to permit calls from the main routine or from other user defined functions by simply using the appropriate CHAN and C BYTE values for the input channel desired and the desired input range APPENDIX Circuit Diagrams MSI P412 Page 14 MSI P412 User Manual
12. o ao 25283 SS ON Ouo ODON td reer ee ee e e a 4 68 O N FOO o o nN yt O O TON Tt N DS O CO ANA N NNN MEM NA o O O O 0 0 0 0 0 O O 0 0 O O O O O O 2 5858885 Mee ee mM SO Figure 3 Jumper block JP1 configuration Page 6 MSI P412 User Manual Table 1 Analog Converter Control Register Addresses Channels Control Output C Data Input I Status Bit 0 7 base 0 base 0 lo base 8 0 base 1 hi 8 15 base 2 base 2 lo base 8 1 base 3 hi 16 23 base 4 base 4 lo base 8 2 base 5 hi 24 31 base 6 base 6 lo base 8 3 base 7 hi 0 31 base 8 4 B Interrupt Connections Interrupt connections are implemented by pins 25 thru 34 of JP1 The steps in the procedure are as follows 1 Pin 30 INT OUT is the composite interrupt signal from the analog converters see circuit diagram in Appendix This is jumpered to a single desired interrupt IRQ4 thru IRQ9 of JP1 shown in Fig 3 This connection causes the interrupt selected to be activated when a conversion is performed 2 If no other cards in the system are using the interrupt line chosen in step 1 proceed to step 3 Pin 26 of JP1 INT IN is used to control the tri state buffer of INT OUT when other cards are using the same interrupt line chosen in step 1 In this case connect pins 26 and 28 of JP1 This results in the tri state buffer of INT OUT
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