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DM210/DM5210 User`s Manual

1. 0000 0000 0000 1111 1111 1110 AD Converted Data 0000 0000 0001 1111 1111 1111 DM5210 analog input module 5 5 RTD Embedded Technologies Inc DM5210 analog input module 5 6 RTD Embedded Technologies Inc APPENDIX A DM210 DM5210 SPECIFICATIONS DM5210 analog input module A 1 RTD Embedded Technologies Inc DM5210 analog input module A 2 RTD Embedded Technologies Inc DM210 DM5210 Characteristics Typical e 25 C Interface Switch selectable base address I O mapped Jumper selectable interrupts Analog Input 16 single ended inputs Input impedance each channel gt 10 megohms eeler 5 10 0 to 10 volts Overvoltage protection sese nnne rennen 35 Vdc Settling time ein certc emt qu c re Pre ne etre a 1 usec max AID Converter see age AD574 TYPE EE Successive approximation ResolutiOn erster o ege DCH 12 bits 2 44 mV 10V 4 88 mV amp 20V IBI 1 LSB typ Conversion Speed on See eterne tones 20 usec typ Sample and hold acquisition time ecceeeceeeeeeeeeeeeeeeeeeeeneeseeeeeneeteeeeneeee 5 usec typ Maximum froughbput essen eene nennen nnns 40 kHz Digital VO 2 LINIEN CMOS 82C55 Optional NMOS 8255 Number of lines rsrennnnrvonnnnvrernnvennvnrennannnnrnnnnnnr 20 16 at I O connector amp 4 on board High level output voltage eese enne 4 2V min Low level output voltage eessem eee 0 45V max High level input voltage rrrrn
2. 4 4 BA 4 8254 Timer Counter 0 ReadiWrte essent enne ener enne 4 6 BA 5 8254 Timer Counter 1 OReadiWrte 4 6 BA 6 8254 Timer Counter 2 Read Write esses enne nennen enne 4 6 BA 7 8254 Control Word Write Only erernvrnrnnvnvnrvennrvenvnenrnnenenerrnnsnrnennnnerrnenrnsenrnsnrssnnnnenrnnnnssennenerssennesener 4 6 BA 8 Read MSB Data Start 12 Bit Conversion Read Write sese ener enne 4 7 BA 9 Read LSB Data Start 8 Bit Conversion Read Write ssssesssssssseseeee enne 4 7 BA 10 Read Status Clear IRQ Read Write sess ener etre enne 4 7 BA E1I IRQ Enable Write Only re Rot ee qr o nee a PR is 4 7 Programming the DM210 DM35210 5 iret d E e t E EE Lt re RI e ute peer esr brass 4 8 Clearing and Setting Bits in a Port assaini ee a as e a a e n R 4 8 A D Conversions EE 4 10 Initializingithe 8255 BEL eee goo e Ee Ee E E se Ge A ES 4 10 Selecting Channel e 5 etre ORO ARR ER E eite 4 10 e Enabling and Disabling Interrupts eessssessseesseeseeseeee eene ener ener en entren ren nennen trennen nene 4 10 Starting an A D Conversion ENEE pp REO ORPHEO HUE Ier bpm EE 4 10 WEE Ee EE 4 10 e Monitoring Conversion Statls nione EES E epe ep o psp ri ENEE 4 11 Reading the Converted Data Luna cet ret e e SERE EE EEE GER Arar Beste ee ete espe tn dg 4 11 Oe ue 4 12 What Is an Interrupt c i reor Eed eebe ee EES 4 12 I
3. A read provides the LSB 4 least significant bits of the A D conversion as defined below The converted data is left justified Writing to this address starts an 8 bit A D conversion the data written is irrelevant X X Bit 3 Bit 2 Bit 1 Bit 0 X X BA 10 Read Status Clear IRQ Read Write A read provides the two status bits defined below The end of convert bit goes high when a conversion is complete The IRQ status bit goes high when an interrupt has occurred and stays high until a clear IRQ command is sent The clear IRQ command is sent by writing to BA 10 data written is irrelevant End of Convert 0 2 no EOC 1 conversion done IRQ Status 0 No IRQ 1 IRQ BA 11 IRQ Enable Write Only A write enables and disables interrupt generation and interrupt sharing Writing a 1 to bit 0 enables interrupt generation writing a 0 disables interrupt generation writing a 1 to bit 1 disables interrupt sharing writing a 0 enables interrupt sharing At power up this register is set to 0 Interrupt Sharing Interrupt Enable Disable 0 enable 0 interrupt disabled 1 disable 1 interrupt enabled DM5210 analog input module 4 7 RTD Embedded Technologies Inc Programming the DM210 DM5210 This section gives you some general information about programming and the 210 5210 and then walks you through the major 210 5210 programming functions These descriptions will help you as you use the exam
4. nte temo m eoo ade 1 7 Pull up Pull down Resistors for the 8255 sse nee en enneenennee nennen 1 8 Adding Pull ups and Pull downs to Digital I O Lmes eese enne 1 9 Gain Circuitry and Formulas for Calculating Gx and 1 10 Diagram for Removal of Solder Shot 1 10 P2 1 0 Connector Pin Assignments 2 2 ern p Pe e RE E Ree EE CI er E Op ett eee 2 4 Analogs Input Connections eoe ete ee eere edu tin e enced nee Seeds 2 5 DM210 DM5210 Block Diagram essere nnne tnter iEn tSr EEn nennen nennen 3 3 A D Conversion Timing Diagram eee etie ii tenta eser esos E KSEE rte e E bereits 4 11 8254 Programmable Interval Timer Circuit Block Diagram eee 4 16 Single Conversion Flow Diagram esee ener ener neen nennen nennen ne teeenn ete nene nenne 4 19 Channel Scanning Flow Diagram uet goto rhe hee e CR ite quet Ue eee S 4 20 Module Layout srn tem enes Dott e E o ee e Et ede Eos tenes ete 5 3 iii iv INTRODUCTION DM5210 analog input module i 1 RTD Embedded Technologies Inc DM5210 analog input module i 2 RTD Embedded Technologies Inc The DM210 and DM5210 dataModule medium speed analog input modules turn your IBM PC compatible cpuModule or other PC 104 computer into a high performance data acquisition and control system Ultra compact for embedded and portable applications the 210 5210 features 16 single ended analog input channels 12 bit 20 microsecond A D converter 5 10 or 0 to 1
5. appropriate signal pin on the I O connector and the low side is connected to any DIGITAL GND Running the 5210DIAG Diagnostics Program Now that your module is ready to use you will want to try it out An easy to use menu driven diagnostics program 5210DIAG is included with your example software to help you verify your module s operation You can also use this program to make sure that your current base address setting does not contend with another device DM5210 analog input module 2 4 RTD Embedded Technologies Inc 1 0 CONNECTOR P2 SIGNAL SOURCE 1 our SIGNAL SOURCE 15 our Fig 2 2 Analog Input Connections DM5210 analog input module 2 5 RTD Embedded Technologies Inc DM5210 analog input module 2 6 RTD Embedded Technologies Inc CHAPTER 3 HARDWARE DESCRIPTION This chapter describes the features of the 210 5210 hardware The major circuits are the A D the 8254 timer counters and the programmable peripheral interface which provides the digital I O lines Module interrupts are also described in this chapter DM5210 analog input module 3 1 RTD Embedded Technologies Inc DM5210 analog input module 3 2 RTD Embedded Technologies Inc The 210 5210 has three major circuits the A D the timer counters and the 8255 programmable peripheral interface PPI which provides the digital I O lines Figure 3 1 shows the block diagram of the module This chapter describes hardware which makes up the major circ
6. change the factory settings Pay special attention to the setting of S1 the base address switch to avoid address contention when you first use your module in your system Table 1 1 Factory Settings Switch Factory Settings Jumper Function Controlled Jumpers Installed Selects the active interrupt channel pulls tri state buffer to ground G for multiple interrupt Interrupt channels disabled jumper applications installed on G ground for buffer Sets the clock sources for the 8254 timer counters Jumpers installed on CLKO OSC TCO TC2 EE OTO amp CLK2 OT1 cascaded EE Sets the analog input voltage range P6 Sets the analog input voltage polarity Selects one of three signals as the interrupt P7 source OT2 P8 18255 Port B bits 4 7 pads for user connections No connections installed St S Sets the base address 300 hex 768 decimal io PZ eeeeeee o 11888 oo oo eeeeeene LW Oe H c e u pm D d p Fig 1 1 Module Layout Showing Factory Configured Settings DM5210 analog input module 1 3 RTD Embedded Technologies Inc P3 Interrupt Channel Select Factory Setting Interrupt Channels Disabled G Connected This header connector shown in Figure 1 2 lets you connect any one of the three interrupt sources on P7 to an interrupt channel IRQ2 highest priority channel through IRQ7 lowest priority channel IRQ2 is the righttmost channel and IRQ7 is the leftmost channel
7. closest to the bus connector are the signal side The bottom four bits of Port B are reserved for on board functions U eo NO o 2 pg Fig 1 8 Port B Bits 4 7 Pads P8 DM5210 analog input module 1 6 RTD Embedded Technologies Inc S1 Base Address Factory Setting 300 hex 768 decimal One of the most common causes of failure when you are first trying your module is address contention Some of your computer s I O space is already occupied by internal I O and other peripherals When the 210 5210 attempts to use I O address locations already used by another device contention results and the module does not work To avoid this problem the 210 5210 has an easily accessible DIP switch S1 which lets you select any one of 32 starting addresses in the computer s I O Should the factory setting of 300 hex 768 decimal be unsuitable for your system you can select a different base address simply by setting the switches to any one of the values listed in Table 1 2 The table shows the switch settings and their corresponding decimal and hexadecimal in parentheses values Make sure that you verify the order of the switch numbers on the switch 1 through 5 before setting them When the switches are pulled forward they are OPEN or set to logic 1 as labeled on the DIP switch package When you set the base address for your module record the value in the table inside the back cover Figure 1 9 shows the DIP switch set for a base address o
8. next to last pair of pins To activate a channel you must install a jumper vertically across the desired IRQ channel s pair of pins Figure 1 2a shows the factory setting Figure 1 2b shows the interrupt source connected to IRQ3 VU 9 e e 3 l Sa BRI dedu F 5 ue oh oe Fig 1 2a Fig 1 2b Interrupt Source Factory Setting Connected to IRQ3 Fig 1 2 Interrupt Channel Jumper P3 This module supports an interrupt sharing mode where the pins labeled G connect a kilohm pull down resistor to the output of a high impedance tri state driver which carries the interrupt request signal This pull down resistor pulls the interrupt request line low whenever interrupts are not active Whenever an interrupt request is made the tri state buffer is enabled forcing the output high and generating an interrupt You can monitor the interrupt status through bit I in the status word I O address location BA 10 After the interrupt has been serviced the reset command returns the IRQ line low disabling the tri state buffer and pulling the output low again Figure 1 3 shows this circuit Because the interrupt request line is pulled low only by the pull down resistor you can have two or more modules which share the same IRQ channel You can tell which module issued the interrupt request by monitoring each module s IRQ status bit If you are not planning on sharing interrupts or if you are not sure that your CPU supports interrupt sharing it is best
9. 1 Group B bn EEE 4 RTD Embedded Technologies Inc The table below shows the control words for the 16 possible Mode 0 Port I O combinations 8255 Port I O Flow Direction and Control Words Mode 0 Control Word Binary ou oua oma ua 19999999 ie w Low moa Oma mem 0091091 vr em mu f oupa oma oup 10010009 i w mu pr ouput Ow 001098 ve 9 mu moa Ow mu vo0moor 319 9 When bit 7 of the PPI control word is set to 0 a write can be used to individually program the Port C lines D7 D6 D5 D4 D3 D2 ol DO Set Reset Bit Set Reset Function Bit 0 set bit to 0 0 active Bit Select 1 set bit to 1 000 PCO 001 PC1 010 PC2 011 PC3 100 PC4 101 PC5 110 PC6 111 PC7 DM5210 analog input module 4 5 RTD Embedded Technologies Inc For example if you want to set Port C bit 0 to 1 you would set up the control word so that bit 7 is 0 bits 1 2 and 3 are 0 this selects PCO and bit 0 is 1 this sets PCO to 1 The control word is set up like this 0 X X X 0 0 0 1 Sets PCO to 1 written to BA 3 X don t care Set Reset Function Bit Set PCO Bit Select 000 PCO BA 4 8254 Timer Counter 0 Read Write A read shows the count in the counter and a write loads the counter with a new value Counting begins as soon as the count is loaded BA 5 8254 Timer Counter 1 Read Write A read shows the count in the co
10. 1 12 Gain Circuitry and Formulas for Calculating Gx and f Remove solder short JS2 from bottom side of module o 9000000Mm Fig 1 13 Diagram for Removal of Solder Short DM5210 analog input module 1 10 RTD Embedded Technologies Inc CHAPTER 2 MODULE INSTALLATION The 210 5210 is easy to install in your cpuModule or other PC 104 based system This chapter tells you step by step how to install and connect the module After you have installed the module and made all of your connections you can turn your system on and run the 5210DIAG diagnostics program included on your example software disk to verify that your module is working DM5210 analog input module 2 1 RTD Embedded Technologies Inc DM5210 analog input module 2 2 RTD Embedded Technologies Inc Module Installation Keep the module in its antistatic bag until you are ready to install it in your cpuModule or other PC 104 based system When removing it from the bag hold the module at the edges and do not touch the components or connec tors Before installing the module in your system check the jumper and switch settings Chapter 1 reviews the factory settings and how to change them If you need to change any settings refer to the appropriate instructions in Chapter 1 Note that incompatible jumper settings can result in unpredictable module operation and erratic response The 210 5210 comes with a stackthrough P1 connector The stackthrough connector lets
11. 240 mA 5 volts 1 2W DM5210 analog input module A 3 RTD Embedded Technologies Inc Connector 50 pin right angle header Environmental Operating temperature cece ceeeeeeeeeneeeeeeeeaeecaeeeaeeesaeseaeeeeeseaeeteaeeeaeetaas 0 to 70 C Storage temperature rrrnnnrnnnvrnonvnnnnnnnnvonnnnnnnvensnnnnnvnnrrnnsnrnnnrnssnrennnnnrnreenn 40 to 85 elt lte EE 0 to 90 non condensing Size 3 55 L x 3 775 W x 0 6 H 90mm x 96mm x 15mm DM5210 analog input module A 4 RTD Embedded Technologies Inc APPENDIX B P2 CONNECTOR PIN ASSIGNMENTS DM5210 analog input module B 1 RTD Embedded Technologies Inc DM5210 analog input module B 2 RTD Embedded Technologies Inc AIN1 AIN2 AIN3 AIN4 AINS AING AIN7 AIN8 ANALOG GND EXT GATE 0 ANALOG GND PA7 PA6 PA5 PA4 PA3 PA2 PA1 PAO EXT CLK 0 EXT GATE 1 EXT CLK 1 EXT CLK 2 12 VOLTS 12 VOLTS AIN9 AIN10 AIN11 AIN12 AIN13 AIN14 AIN15 AIN16 ANALOG GND ANALOG GND ANALOG GND PC7 PC6 PC5 PC4 PC3 PC2 PC1 PCO T C OUT 0 T C OUT 1 T C OUT 2 EXT GATE 2 5 VOLTS DIGITAL GND PIN 1 PIN 49 EP aS PIN 2 E Eer BS S IE UU I Wu TM M ae I JA REE OU PIN 50 I AN O P2 Mating Connector Part Numbers Manufacturer PartNumber DM5210 analog input module B 3 RTD Embedded Technologies Inc DM5210 analog inp
12. EXT CLK 1 O O COUNTER CLK 1 EXT GATE 1 GATE PIN 414 PIN 424 T C OUT 1 OUT l l l COUNTER CLK PIN 156 EXT CLK 2 2 257 rq E SE E 5 V GATE PIN 464 EXT GATE 2 PIN 441 T C OUT 2 OUT O Fig 4 2 8254 Programmable Interval Timer Circuit Block Diagram Each timer counter has two inputs CLK in and GATE in and one output timer counter OUT They can be programmed as binary or BCD down counters by writing the appropriate data to the command word as described in the I O map section at the beginning of this chapter One of two clock sources the on board 8 MHz crystal or an external clock can be selected as the clock input to each timer counter In addition the timer counters can be cascaded by connecting TCO s output to TC1 s clock input and TC1 s output to TC2 s clock input The diagram shows how these clock sources are connected to the timer counters An external gate source can be connected to each timer counter through the I O connector When a gate is disconnected an on board pull up resistor automatically pulls the gate high enabling the timer counter The output from each timer counter is available at the I O connector where it can be used for interrupt genera tion or for counting functions The timer counters can be programmed to operate in one of six modes depending on your application The following paragraphs briefly describe each mode Mode 0 Event Counter Interrupt on Termina
13. Note that 8 bit A D conversions can also be performed by writing to I O location BA 9 to start a conversion While an 8 bit conversion has a lower resolution it is performed more rapidly since the converted data is contained in a single byte The key digital codes and their input voltage values are given for 12 bit and 8 bit conversions in the following two tables DM5210 analog input module 4 11 RTD Embedded Technologies Inc ser BEE Aen 0 to 10 Volts Output Code 19 9976 volts 7 500 vols 15 000 volts 12 500 vol ovols For 0 to 10 amp 5 volts 1 LSB 2 44 millivolts for 10 volts 1 LSB 4 88 millivolts ET BN Output Code For 0 to 10 amp 5 volts 1 LSB 39 063 millivolts for 10 volts 1 LSB 78 126 millivolts Interrupts What Is an Interrupt An interrupt is an event that causes the processor in your computer to temporarily halt its current process and execute another routine Upon completion of the new routine control is returned to the original routine at the point where its execution was interrupted Interrupts are very handy for dealing with asynchronous events events that occur at less than regular intervals Keyboard activity is a good example your computer cannot predict when you might press a key and it would be a waste of processor time for it to do nothing while waiting for a keystroke to occur Thus the interrupt scheme is used and the processor proceeds with other tasks Then when a
14. PPI Port B port at BA 1 The bit structure diagram above shows you the four bit instruction for each of the 16 channels Enabling and Disabling Interrupts Any time you use interrupts this bit bit 1 at port BA 11 must be set high to enable the IRQ circuitry Starting an A D Conversion A D conversions are started by writing to the appropriate I O port For 12 bit conversions Port BA 8 is used For 8 bit conversions Port BA 9 is used A START CONVERT command must be issued for each A D conver sion The data written to start a conversion is irrelevant Figure 4 1 shows the timing diagram for A D conversions Channel Scanning If you want to sample a sequence of channels you can set up the 210 5210 for channel scanning The main concern when you scan channels is that you allow enough settling time between the selection of the channel and the start of the A D conversion The channel scanning flow diagram at the end of this chapter explains how to properly program for channel scanning and avoid settling time problems DM5210 analog input module 4 10 RTD Embedded Technologies Inc Start Convert A D Status Converting Not Convertfignverting Not End of Convert Read Data LSB MSB LSB MSB Fig 4 1 A D Conversion Timing Diagram Monitoring Conversion Status The A D conversion status can be monitored through the end of convert EOC signal This signal the inverse of the STATUS signal output by the A D
15. XB50 prototype terminal board for easy signal access and prototype development the DM14 extender board for testing your module in a conventional desktop computer and XP50 flat ribbon cable assembly for external interfacing Optional Configurations Other configurations of the 210 5210 are available such as vertical connectors on some or all I O connectors a right angle or other type of connector for easy use of the four digital I O lines brought out to pads or a non stackthrough bus connector If you need an optional configuration for your requirements please consult the factory Using This Manual This manual is intended to help you install your new module and get it running quickly while also providing enough detail about the module and its functions so that you can enjoy maximum use of its features even in the most complex applications We assume that you already have an understanding of data acquisition principles and that you can customize the example software or write your own applications programs When You Need Help This manual and the example programs in the software package included with your module provide enough information to properly use all of the module s features If you have any problems installing or using this module contact our Technical Support Department 814 234 8087 during regular business hours eastern standard time or eastern daylight time or send a FAX requesting assistance to 814 234 5218 When sending
16. and procedures in your program and it can access global data If you are writing your first ISR we recommend that you stick to the basics just something that will convince you that it works such as incrementing a global variable NOTE If you are writing an ISR using assembly language you are responsible for pushing and popping registers and using IRET instead of RET There are a few cautions you must consider when writing your ISR The most important is do not use any DOS functions or routines that call DOS functions from within an ISR DOS is not reentrant that is a DOS function cannot call itself In typical programming this will not happen because of the way DOS is written But what about when using interrupts Then you could have a situation such as this in your program If DOS function X is being executed when an interrupt occurs and the interrupt routine makes a call to DOS function X then function X is essentially being called while it is already active Such a reentrancy attempt spells disaster because DOS functions are not written to support it This is a complex concept and you do not need to understand it Just make sure that you do not call any DOS functions from within your ISR The one wrinkle is that unfortunately it is not obvious which library routines included with your compiler use DOS functions A rule of thumb is that routines which write to the screen or check the status of or read the keyboard and any disk I O routines
17. float high during the few moments before the board is first initialized This can cause the external devices connected to these lines to operate erratically By pulling these lines down when the data acquisition system is first turned on the motors will not switch on before the 8255 is initialized To use the pull up pull down feature you must first install single in line resistor packs in any or all of the three locations around the 8255 labeled PA Port A PCL Port C lower and PCH Port C upper The four Port B lines cannot be pulled up or down by installing resistor packs PA takes a 10 pin pack and CL and CH take 6 pin packs Figure 1 10 shows this circuitry After the resistor packs are installed you must connect them into the circuit as pull ups or pull downs Locate the three hole pads on the module near the resistor packs They are labeled G for ground on one end and V for 5V on the other end The middle hole is common PA is for Port A CL is for Port C Lower and CH is for Port C Upper To operate as pull ups solder a jumper wire between the common pin middle pin of the three and the V pin For pull downs solder a jumper wire between the common pin middle pin and the G pin Figure 1 11 shows Port A lines with pull ups Port C Lower with pull downs and Port C Upper with no resistors Fig 1 10 Pull up Pull down Resistors for the 8255 DM5210 analog input module 1 8 RTD Embedded Technologies Inc PULL UP
18. is installed in each group of two or three CLK pins P4 osc o Q ECO Z OTO o osc EC1 OT1 OSC N EC2 Fig 1 4 8254 Timer Counter Clock Source Jumpers P4 5200 1 0 CONNECTOR P2 8 MHz l l l EXT CLK 0 O W E5 V pin 18 EXT GATE 0 TIMER COUNTER 0 PIN 39 PIN 404 T C OUT 0 I I I I I I I I I I I I I I I timer PIN 43 EXT CLK 1 I COUNTER O O I PIN 41A EXT GATE 1 I O I I I I I I I I I I I I I PIN 424 T C OUT 1 TIMER I PIN 45 COUNTER O PE Sss aes 5 V PIN 48h EXT GATE 2 PIN 4447 6 OUT 2 Fig 1 5 8254 Timer Counter Circuit Block Diagram DM5210 analog input module 1 5 RTD Embedded Technologies Inc P5 Analog Input Voltage Range Factory Setting 10V This header connector shown in Figure 1 6 lets you select the analog input voltage range The range is set by placing the jumper across the pair of pins labeled 10V giving you a 10 volt range or by placing the jumper across the pins labeled 20V giving you a 20 volt range Note that when you place a jumper across 20V you must place the jumper on P6 across the pins bipolar range of 10 to 10 volts The setting on P6 cannot be used with 20V P6 Analog Input Voltage Polarity Factory Setting Bipolar This header connector shown in Figure 1 6 lets you select the analog input polarity by placing a jumper across the pins labeled for 0 to 10
19. read and or transferred to PC memory one byte at a time through the PC data bus 8254 Timer Counter An 8254 programmable interval timer contains three 16 bit 8 MHz timer counters to support a wide range of timing and counting functions The clock gate and output pins for each of the three timer counters are available at the I O connector Digital UO The 210 5210 has 20 TTL CMOS compatible digital I O lines which can be directly interfaced with external devices or signals to sense switch closures trigger digital events or activate solid state relays The lines are provided by the on board 8255 programmable peripheral interface PPI chip Sixteen of the lines are brought out to the I O connector and four are available at a set of on board pads located near the edge of the module for easy access Pads for installing and activating pull up or pull down resistors are included on the module for the 16 lines brought out to the I O connector Installation procedures are given at the end of Chapter 1 Module Settings What Comes With Your Module You receive the following items in your 210 5210 package DM210 or DM5210 interface module with stackthrough bus header Mounting hardware Software and diagnostics diskette with example programs in BASIC and Turbo C source code User s manual If any item is missing or damaged please call RTD Embedded Technologies Inc Customer Service Department at 814 234 8087 If you require service out
20. the routines called by the main programs Analog to Digital SOFTTRIG Demonstrates how to use a software trigger for acquiring data Timer Counters TIMER A short program demonstrating how to program the 8254 for use as a timer Digital I O DIGITAL Simple program that shows how to read and write the digital I O lines Interrupts INTRPTS Shows the bare essentials required for using interrupts INTSTR A complete program showing interrupt based streaming to disk BASIC Programs These programs are source code files so that you can easily develop your own custom software for the 210 5210 Analog to Digital SINGLE Demonstrates how to perform single conversions SCAN Demonstrates how to change channels while acquiring data Timer Counters TIMER A short program demonstrating how to program the 8254 for use as a timer Digital I O DIGITAL Simple program that shows how to read and write the digital I O lines Flow Diagrams DM5210 analog input module 4 18 RTD Embedded Technologies Inc The following paragraphs provide a description and flow diagrams for performing A D conversions and channel scanning These diagrams will help you to build your own custom applications programs Single Convert Flow Diagram Figure 4 3 This flow diagram shows you the steps for taking a single sample on a selected channel A sample is taken each time you send the Start Convert command All of the samples will be taken on the same channel and until y
21. through the programming steps for performing A D conversions Detailed information about the conversion modes is presented in this section You can follow these steps on the flow diagrams at the end of this chapter and in our example programs included with the module In this discussion BA refers to the base address Initializing the 8255 PPI Four of the eight 8255 Port B lines are used to control the channel selection for taking a reading Port B is programmed at I O address location BA 1 x X D D CH3 CH2 CH1 CHO BA 1 rove D7 D6 per D4 D3 D2 D1 DO Analog Input Channel Select 0000 channel 1 0001 channel 2 1000 channel 9 1001 channel 10 0010 channel 3 0011 channel 4 0100 channel 5 0101 channel 6 0110 channel 7 0111 channel 8 1010 channel 11 1011 channel 12 1100 channel 13 1101 channel 14 1110 channel 15 1111 channel 16 To use Port B for these control functions the 8255 must be initialized so that Port B is set up as a Mode 0 output port This is done by writing this data to the PPI control word at I O address BA 3 X don t care 1 X X X X 0 0 X The top four bits of Port B are brought out to on board pads where they are available for your use Keep in mind that when you are programming some of the bits in this port you may need to preserve the state of other bits Selecting a Channel To select a conversion channel you must assign values to bits 0 through 3 in the
22. you stack another module on top of your 210 5210 To install the module follow the procedures described in the computer manual and the steps below 1 Turn OFF the power to your system 2 Touch a metal rack to discharge any static buildup and then remove the module from its antistatic bag 3 Select the appropriate standoffs for your application to secure the module when you install it in your system two sizes are included with the module 4 Holding the module by its edges orient it so that the P1 bus connector s pin I lines up with pin I of the expansion connector onto which you are installing the module 5 After carefully positioning the module so that the pins are lined up and resting on the expansion connector gently and evenly press down on the module until it is secured on the connector NOTE Do not force the module onto the connector If the module does not readily press into place remove it and try again Wiggling the module or exerting too much pressure can result in damage to the 210 5210 or to the mating module 6 After the module is installed connect the cable to I O connector P2 on the module When making this connection note that there is no keying to guide you in orientation You must make sure that pin 1 of the cable is connected to pin 1 of P2 pin 1 is marked on the module with a small square For twisted pair cables pin 1 is the dark brown wire for standard single wire cables pin 1 is the red wire 7 Ma
23. 0 volt analog input range Resistor configurable gain 20 TTL CMOS 8255 based programmable digital I O 16 at I O connector 4 at on board pads Three independent 16 bit 8 MHz timer counters 5 volt only operation DM5210 BASIC and Turbo C source code diagnostics program Note that the difference between the DM210 and DM5210 is the power supply requirements the DM210 requires 12 and 5 volt power sources and the DM5210 requires a 5 volt source The following paragraphs briefly describe the major functions of the module A detailed discussion of module functions is included in subsequent chapters Analog to Digital Conversion The analog to digital A D circuitry receives up to 16 single ended analog inputs and converts these inputs into 12 bit digital data words which can then be read and or transferred to PC memory The analog input voltage range is jumper selectable for bipolar ranges of 5 to 5 volts or 10 to 10 volts or a unipolar range of 0 to 10 volts The module is factory set for 5 to 5 volts Overvoltage protection to 35 volts is provided at the inputs A D conversions are performed by a 12 bit successive approximation converter This high performance converter and the high speed sample and hold amplifier preceding it make sure that dynamic input voltages are accurately digitized The resolution of a 12 bit conversion is 2 4414 millivolts and the maximum throughput is 40 000 samples per second The converted data is
24. 2 9990 23 4 88 4997 56 9995 12 2 44 5000 00 10000 00 4843 75 9687 50 156 25 DM5210 analog input module 5 4 RTD Embedded Technologies Inc Data Values for Calibrating Unipolar Range 0 to 10 volts Offset TR4 Converter Gain TR1 Input Voltage 1 22070 mV Input Voltage 9 99634 V 0000 0000 0000 1111 1111 1110 AD Converted Data 0000 0000 0001 1111 1111 1111 Bipolar Calibration Two adjustments are made to calibrate the A D converter for the bipolar ranges of 5 and 10 volts One is the offset adjustment and the other is the full scale or gain adjustment Trimpot TR2 is used to make the offset adjust ment and trimpot TR1 is used for gain adjustment These adjustments are made with the module set for a range of 5 to 5 volts Before making these adjustments make sure that the jumpers on P5 and P6 are set for this range Use analog input channel 1 gain 1 while calibrating the module Connect your precision voltage source to channel 1 Set the voltage source to 4 99878 volts start a conversion and read the resulting data Adjust trimpot TR2 until it flickers between the values listed in the table below Next set the voltage to 4 99634 volts and repeat the procedure this time adjusting TR1 until the data flickers between the values in the table Data Values for Calibrating Bipolar Ranges Using 5 to 5 volts Offset TR2 Converter Gain TR1 Input Voltage 4 99878V Input Voltage 4 99634V
25. 210 program disk for a better under standing of interrupt program development Writing an Interrupt Service Routine ISR The first step in adding interrupts to your software is to write the interrupt service routine ISR This is the routine that will automatically be executed each time an interrupt request occurs on the specified IRQ An ISR is different than standard routines that you write First on entrance the processor registers should be pushed onto the DM5210 analog input module 4 13 RTD Embedded Technologies Inc stack BEFORE you do anything else Second just before exiting your ISR you must clear the interrupt status of the 210 5210 and write an end of interrupt command to the 8259 controller Finally when exiting the ISR in addition to popping all the registers you pushed on entrance you must use the IRET instruction and not a plain RET The IRET automatically pops the flags CS and IP that were pushed when the interrupt was called If you find yourself intimidated by interrupt programming take heart Most Pascal and C compilers allow you to identify a procedure function as an interrupt type and will automatically add these instructions to your ISR with one important exception most compilers do not automatically add the end of interrupt command to the procedure you must do this yourself Other than this and the few exceptions discussed below you can write your ISR just like any other routine It can call other functions
26. DM210 DM5210 User s Manual TET RTD Embedded Technologies Inc Real Time Devices Accessing the Analog World BDM 610010022 AS9100 and ISO 9001 Certified Rev B DM210 DM3210 User s Manual RTD Embedded Technologies INC 103 Innovation Blvd State College PA 16803 0906 Phone 1 814 234 8087 FAX 1 814 234 5218 E mail sales rtd com techsupport rtd com web site http www rtd com Revision History Rev A New manual naming method Rev B Changed pictures to match Rev B PCB Published by RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 Copyright 1999 2002 2003 by RTD Embedded Technologies Inc All rights reserved Printed in U S A The RTD Logo is a registered trademark of RTD Embedded Technologies cpuModule and utilityModule are trademarks of RTD Embedded Technologies PhoenixPICO and PheonixPICO BIOS are trademarks of Phoenix Technologies Ltd PS 2 PC XT PC AT and IBM are trademarks of International Business Machines Inc MS DOS Windows Windows 95 Windows 98 and Windows NT are trademarks of Microsoft Corp PC 104 is a registered trademark of PC 104 Consortium All other trademarks appearing in this document are the property of their respective owners Table of Contents LIST OF ILLUSTRATIONS geegent Analog to Digital Conversion oio ce re ree ete cbse PR rb E EIEE EES i 3 8254 KE EE 1 3 Digital Jl O EE entr get e
27. First read in the port and clear bits 3 4 and 5 by ANDing them with 199 Then set bits 3 and 5 by ORing them with 40 and finally write the resulting value back to the port In C this is programmed as v inportb port address v v amp 199 v v 40 outportb port address v A final note Don t be intimidated by the binary operators AND and OR and try to use operators for which you have a better intuition For instance if you are tempted to use addition and subtraction to set and clear bits in place of the methods shown above DON T Addition and subtraction may seem logical but they will not work if you try to clear a bit that is already clear or set a bit that is already set For example you might think that to set bit 5 of a port you simply need to read in the port add 32 2 to that value and then write the resulting value back to the port This works fine if bit 5 is not already set But what happens when bit 5 is already set Bits 0 to 4 will be unaffected and we can t say for sure what happens to bits 6 and 7 but we can say for sure that bit 5 ends up cleared instead of being set A similar problem happens when you use subtraction to clear a bit in place of the method shown above Now that you know how to clear and set bits we are ready to look at the programming steps for the 210 5210 module functions DM5210 analog input module 4 0 RTD Embedded Technologies Inc A D Conversions The following paragraphs walk you
28. HAPTER 5 CALIBRATION eeseseseesserssesssessessersseessenseeserssesssesssserssesssenseeserssesssensessesenseseser 5 1 Required Equipment ise bee tec t REIR ERU RU ere EE 5 3 A D Calbr ation aseene ape 5 4 Unipolar Calibration eieiei EE EMIS eee tie EEN 5 4 Bipolar C lbration sed ine rette etie a aee hmi eet ei n n am REPE 5 5 APPENDIX A DM210 DM3210 SPECIFICATIONS i serenveevsevveveenvnnvenevnveneenesnssnnvnnvenennveneere A I APPENDIX B P2 CONNECTOR PIN ASSIGNMENTS cccsssssssssssssssssssssessssssessessesees B 1 APPENDIX C COMPONENT DATA SHEETS eeeeeeeee eese esee eene ene en senssnsessenssesessess C 1 APPENDIX D WARRANTY AND RETURN POLICY ceres eneeneeses D 1 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 1 9 1 10 1 11 1 12 1 13 2 1 29 3 1 4 1 4 2 4 3 4 4 5 1 List of Illustrations Module Layout Showing Factory Configured Settings sees 1 3 Interrupt Channel Jumper B3 eoe eee EAR 1 4 Pulling Down the Interrupt Request Line esee eene enn nennen tenen netten 1 4 8254 Timer Counter Clock Source Jumpers P4 sese iisi 1 5 8254 Timer Counter Circuit Block Diagram srrnrorvrrernnvrrenrvnrrenrrnvvrvernvrrvennvrrnensvnnveevverneesvervresvarvrsvrasvsve 1 5 Analog Input Voltage Range and Polarity P5 and D 1 6 Interrupt Source Juniper PT sss 5 eene prp tte e eet ies 1 6 Port P Bits 4 7 Pads P8 si noie Dee anal e EE e Ebr ERA 1 6 Base Address Switch Sl
29. OR EH D REPE ERG RERO I Ge et epe i 3 What Comes Wath Your Module ette rrr eroe erre ttr ERE con weebuepevsncvscgeuenss FERE SES NEAR acon ENEE Ed 1 3 lee EE 1 4 Application Software and Drivers sesssesseseeeeeeeeee eene nennen nennen ES Ee EEEE aE Eies 1 4 IS Etgen el 1 4 Optional Configurations eoe d teet tre nete EE etg Ree onte ette 1 4 Using This Manual E 1 4 When You Need Hel psc ate Sse tom e tm rie Eeer tue RO ed e kaiene i 4 CHAPTER 1 MODULE SETTINGS sciscsisscsaiestsssueuswacoidtess vesensteassesdecexsessssseusescsteidesassenseansoscese l 1 Factory Configured Switch and Jumper Settings esses eene inen nremren nennen 3 P3 Interrupt Channel Select Factory Setting Interrupt Channels Disabled G Connected 4 P4 8254 Timer Counter Clock Sources Factory Settings CLK0 OSC CLK1 OTO CLK2 OT1 5 P5 Analog Input Voltage Range Factory Setting 10V sees enne en ene 6 P6 Analog Input Voltage Polarity Factory Setting Bipolar sese 6 P7 Interrupt Source Factory Setting OT 6 P8 8255 Port B Bits 4 7 Pads Factory Setting No Connections sese 6 S1 Base Address Factory Setting 300 hex 768 decimal eese nere 7 Pull up Pull down Resistors on Digital I O Lines eene nennen nennen nennen ene en rene 8 Gx Resistor Configurable Gin ete due aee saben su t
30. PORT C UPPER PC4 7 Fig 1 11 Adding Pull ups and Pull downs to Digital I O Lines Gx Resistor Configurable Gain The 210 5210 has a resistor configurable gain circuitry Gx so that you can easily configure special gain settings for a specific application Note that when you use this feature all of the input channels will operate only at your custom gain setting Gx is derived by adding resistors R1 and R2 trimpot TR3 and capacitor C21 all located in the upper right area of the module The resistors and trimpot combine to set the gain as shown in the formula in Fig ure 1 12 Capacitor C21 is provided so that you can add low pass filtering in the gain circuit If your input signal is a slowly changing one and you do not need to measure it at a higher rate you may want to add a capacitor at C21 in order to reduce the input frequency range and in turn reduce the noise on your input signal The formula for setting the frequency is given in the diagram Figure 1 12 shows how the Gx circuitry is configured As shown in Figure 1 12 a solder short must be removed from the module to activate the Gx circuitry This short is located on the bottom side of the module under U11 AD712 IC Figure 1 13 shows the location of the solder short DM5210 analog input module 1 9 RTD Embedded Technologies Inc 3 Remove solder short see Figure 1 13 H1 To calculate Gx Gx TR3 R2 R1 1 To calculate frequency f 1 2bC21 R2 TR3 Fig
31. PPI Port C Read Port C digital input lines lines BA 2 8255 PPI Control Word heseved Program PPI configuration BA 3 8254 Timer Counter 0 Read count value Load count register BA 4 8254 Timer Counter 2 Read count value Load count register BA 6 8254 Timer Counter Control Word Reserved Program counter mode BA 7 Read Data Read A D converted data Start 12 bit Conversion MSB Start 12 bit A D conversion BA 8 Read Data Start 8 bit Conversion Read A D converted data LSB Start 8 bit A D conversion BA 9 Read Status Clear IRQ Readstatus word Clear interrupt line BA 10 Enable and disable interrupt IRQ Enable Reserved generation BA 11 BA Base Address BA 0 PPI Port A Digital I O Read Write Transfers the 8 bit Port A digital input and digital output data between the module and an external device A read transfers data from the external device through P2 and into PPI Port A a write transfers the written data from Port A through P2 to an external device 8254 Timer Counter 1 Read count value Load count register BA 5 BA 1 PPI Port B Channel Select Read Write The bottom four bits PBO PB3 program the analog input channel The remaining four bits PB4 PB7 are brought out onto on board pads labeled P8 so that they can be used for digital control functions Remember that if you are using these four lines for control operations you must preserve their settings when you write to this port to change channels or enable in
32. RQ4 by COMI and IRQ6 by the disk drives Therefore it is important for you to know which IRQ lines are available in your system for use by the 210 5210 8259 Programmable Interrupt Controller The chip responsible for handling interrupt requests in the PC is the 8259 Programmable Interrupt Controller To use interrupts you need to know how to read and set the 8259 s interrupt mask register IMR and how to send the end of interrupt EOI command to the 8259 Interrupt Mask Register IMR Each bit in the interrupt mask register IMR contains the mask status of an IRQ line bit 0 is for IRQO bit 1 is for IRQ1 and so on If a bit is set equal to 1 then the corresponding IRQ is masked and it will not generate an interrupt If a bit is clear equal to 0 then the corresponding IRQ is unmasked and can generate interrupts The IMR is programmed through port 21H IRQ7 IRQ6 IRQS IRQ4 IRQ3 IRQ2 IRQ1 IRQO VO Port 21H For all bits 0 IRQ unmasked enabled 1 IRQ masked disabled End of Interrupt EOI Command After an interrupt service routine is complete the 8259 interrupt controller must be notified This is done by writing the value 20H to I O port 20H What Exactly Happens When an Interrupt Occurs Understanding the sequence of events when an interrupt is triggered is necessary to properly write software interrupt handlers When an interrupt request line is driven high by a peripheral device such as th
33. SULT OF SERVICE OR MODIFICATION BY ANYONE OTHER THAN RTD Embedded Technologies EXCEPT AS EXPRESSLY SET FORTH ABOVE NO OTHER WAR RANTIES ARE EXPRESSED OR IMPLIED INCLUDING BUT NOT LIMITED TO ANY IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE AND RTD Embedded Technologies EXPRESSLY DISCLAIMS ALL WARRANTIES NOT STATED HEREIN ALL IMPLIED WARRANTIES INCLUDING IMPLIED WARRANTIES FOR MECHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE LIMITED TO THE DURATION OF THIS WARRANTY IN THE EVENT THE PRODUCT IS NOT FREE FROM DEFECTS AS WARRANTED ABOVE THE PURCHASER S SOLE REMEDY SHALL BE REPAIR OR REPLACEMENT AS PROVIDED ABOVE UNDER NO CIRCUMSTANCES WILL RTD Embedded Technologies BE LIABLE TO THE PURCHASER OR ANY USER FOR ANY DAMAGES INCLUDING ANY INCIDEN TAL OR CONSEQUENTIAL DAMAGES EXPENSES LOST PROFITS LOST SAVINGS OR OTHER DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE PRODUCT SOME STATES DO NOT ALLOW THE EXCLUSION OR LIMITATION OF INCIDENTAL OR CONSEQUENTIAL DAMAGES FOR CONSUMER PRODUCTS AND SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS SO THE ABOVE LIMITATIONS OR EXCLUSIONS MAY NOT APPLY TO YOU THIS WARRANTY GIVES YOU SPECIFIC LEGAL RIGHTS AND YOU MAY ALSO HAVE OTHER RIGHTS WHICH VARY FROM STATE TO STATE DM5210 analog input module D 3 RTD Embedded Technologies Inc RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 USA Our webs
34. a FAX request please include your company s name and address your name your telephone number and a brief description of the problem DM5210 analog input module i 4 RTD Embedded Technologies Inc CHAPTER 1 MODULE SETTINGS The 210 5210 has jumper and switch settings you can change if necessary for your application The module is factory configured with the settings listed in Table 1 1 and shown on the module diagram at the beginning of this chapter Should you need to change these settings use these easy to follow instructions before you install the module in your system By installing resistor packs and soldering jumpers in the de sired locations in the associated pads as described near the end of the chapter you can configure 16 of your digital I O lines to be pulled up or pulled down The final section describes how to install two resistors and a trimpot to set the resistor configurable gain to the value required for your application A pad for installing a capacitor is also in cluded in the gain circuitry for creating a low pass filter DM5210 analog input module 1 1 RTD Embedded Technologies Inc DM5210 analog input module 1 2 RTD Embedded Technologies Inc Factory Configured Switch and Jumper Settings Table 1 1 lists the factory settings of the user configurable jumpers and switch on the 210 5210 Figure 1 1 shows the module layout and the locations of the factory set jumpers The following paragraphs explain how to
35. a bMODc a b c a bANDc a bORc Many compilers have functions that can read write either 8 or 16 bits from to an I O port For example Turbo Pascal uses Port for 8 bit port operations and PortW for 16 bits Turbo C uses inportb for an 8 bit read of a port and inport for a 16 bit read Be sure to use only 8 bit operations with the 210 5210 Clearing and Setting Bits in a Port When you clear or set one or more bits in a port you must be careful that you do not change the status of the other bits You can preserve the status of all bits you do not wish to change by proper use of the AND and OR binary operators Using AND and OR single or multiple bits can be easily cleared in one operation To clear a single bit in a port AND the current value of the port with the value b where b 255 2 Example Clear bit 5 in a port Read in the current value of the port AND it with 223 223 255 2 and then write the resulting value to the port In BASIC this is programmed as V INP PortAddress V V AND 223 OUT PortAddress V DM5210 analog input module 4 8 RTD Embedded Technologies Inc To set a single bit in a port OR the current value of the port with the value b where b 2 Example Set bit 3 in a port Read in the current value of the port OR it with 8 8 23 and then write the resulting value to the port In Pascal this is programmed as V Port PortAddress V VOR 8 Port PortAddress V Setting or cl
36. annel is started ensures that enough time is allowed for the new channel to settle before the next conversion is started regardless of your PC type Except for the initial delay between the starting channel selection and first conversion you do not have to be concerned with building delays into your program and the accuracy of the conversions when following this program structure Note that the data you read in the Read LSB Read MSB steps will always be the data from the previously selected channel not the data from the channel selected in the Select Next Channel block Program 8255 PPI Port B out Select Starting Channel Start Conversion BA 8 for 12 bit BA 9 for 8 bit Select Next Channel Check End of Convert EOC 1 Read LSB BA 9 Contains bits 0 3 of 12 bit conversion Read MSB BA 8 Contains bits 4 11 of 12 bit conversion bits 0 7 of 8 bit conversion Stop Program Fig 4 4 Channel Scanning Flow Diagram DM5210 analog input module 4 20 RTD Embedded Technologies Inc CHAPTER 5 CALIBRATION This chapter tells you how to calibrate the 210 5210 using the 5210DIAG calibration program included in the example software package and the three trimpots on the module These trimpots calibrate the A D converter gain and offset DM5210 analog input module 5 1 RTD Embedded Technologies Inc DM5210 analog input module 5 2 RTD Embedded Technologies Inc This chapter te
37. converter is low when a conversion is in progress and goes high when the conversion is completed This low to high transition can be used to generate an interrupt Reading the Converted Data The general algorithm for taking an A D reading is 1 Start a 12 bit conversion by writing to BA 8 out base address 8 0 Note that the value you send is not important The act of writing to this I O location is the key to starting a conversion 2 Delay at least 20 microseconds or monitor end of convert for a transition or use an interrupt 3 Read the least significant byte of the converted data from BA 9 lsb inp base address 9 4 Read the most significant byte of the converted data from BA 8 msb inp base address 8 5 Combine them into the 12 bit result by shifting the LSB four bits to the right The MSB must also be weighted correctly result msb 16 1sb 16 For a 12 bit conversion the A D data read is left justified in a 16 bit word with the least significant four bits equal to zero Because of this the two bytes of A D data read must be scaled to obtain a valid A D reading For example for a voltage range of 5 volts once the reading is calculated it can be correlated to a voltage value by subtracting 2048 to scale it and then multiplying by 2 4414 millivolts For example if the A D reading is 1024 the analog input voltage is calculated as follows 1024 2048 bits 2 4414 mV bit 2 49999 volts
38. e 210 5210 the interrupt controller checks to see if interrupts are enabled for that IRQ and then checks to see if other interrupts are active or requested and determines which interrupt has priority The interrupt controller then interrupts the processor The current code segment CS instruction pointer IP and flags are pushed on the stack for storage and a new CS and IP are loaded from a table that exists in the lowest 1024 bytes of memory This table is referred to as the inter rupt vector table and each entry is called an interrupt vector Once the new CS and IP are loaded from the interrupt vector table the processor begins executing the code located at CS IP When the interrupt routine is completed the CS IP and flags that were pushed on the stack when the interrupt occurred are now popped from the stack and execution resumes from the point where it was interrupted Using Interrupts in Your Programs Adding interrupts to your software is not as difficult as it may seem and what they add in terms of performance is often worth the effort Note however that although it is not that hard to use interrupts the smallest mistake will often lead to a system hang that requires a reboot This can be both frustrating and time consuming But after a few tries you ll get the bugs worked out and enjoy the benefits of properly executed interrupts In addition to reading the following paragraphs study the INTRPTS source code included on your 210 5
39. earing more than one bit at a time is accomplished just as easily To clear multiple bits in a port AND the current value of the port with the value b where b 255 the sum of the values of the bits to be cleared Note that the bits do not have to be consecutive Example Clear bits 2 4 and 6 in a port Read in the current value of the port AND it with 171 171 255 2 2 2 and then write the resulting value to the port In C this is programmed as v inportb port address v v amp 171 outportb port address v To set multiple bits in a port OR the current value of the port with the value b where b the sum of the individual bits to be set Note that the bits to be set do not have to be consecutive Example Set bits 3 5 and 7 in a port Read in the current value of the port OR it with 168 168 2 2 2 and then write the resulting value back to the port In assembly language this is programmed as mov dx PortAddress in al dx or al 168 out dx al Often assigning a range of bits is a mixture of setting and clearing operations You can set or clear each bit individually or use a faster method of first clearing all the bits in the range then setting only those bits that must be set using the method shown above for setting multiple bits in a port The following example shows how this two step operation is done Example Assign bits 3 4 and 5 in a port to 101 bits 3 and 5 set bit 4 cleared
40. ersions can be performed when speed is more critical than resolution Eight bit conversions can increase the throughput rate to about 45 kHz DM5210 analog input module 3 3 RTD Embedded Technologies Inc Timer Counters An 8254 programmable interval timer provides three 16 bit 8 MHz timer counters to support a wide range of timing and counting functions These timer counters can be cascaded or used individually for many applications Each timer counter has two inputs CLK in and GATE in and one output timer counter OUT The clock sources for the timer counters can be selected using jumpers on header connector P4 see Chapter 1 The timer counters can be programmed as binary or BCD down counters by writing the appropriate data to the command word as described in Chapter 4 The command word also lets you set up the mode of operation The six programmable modes are Mode 0 Event Counter Interrupt on Terminal Count Mode 1 Hardware Retriggerable One Shot Mode 2 Rate Generator Mode 3 Square Wave Mode Mode 4 Software Triggered Strobe Mode 5 Hardware Triggered Strobe Retriggerable These modes are detailed in the 8254 Data Sheet reprinted from Intel in Appendix C Digital I O Programmable Peripheral Interface The 8255 programmable peripheral interface PPI is used for digital I O functions This high performance TTL CMOS compatible chip has 24 digital I O lines divided into two groups of 12 lines each Group A Port A 8 lines a
41. f 300 hex 768 decimal Table 1 2 Base Address Switch Settings S1 Base Address Switch Setting Base Address Switch Setting Decimal Hex 54321 Decimal Hex 54321 512 200 10000 528 010 10001 544 020 10010 560 230 10011 576 240 10100 5921 250 10101 608 260 10110 624170 10111 640 280 11000 656 290 11001 6721 AD 11010 688 BO 11011 704 QCO 11100 7201 200 11101 736 1 CEO 11110 7521 QFO EERE Fig 1 9 Base Address Switch S1 DM5210 analog input module 1 7 RTD Embedded Technologies Inc Pull up Pull down Resistors on Digital I O Lines The 8255 programmable peripheral interface provides 20 TTL CMOS compatible digital I O lines which can be interfaced with external devices These lines are divided into four groups eight Port A lines four upper Port B lines the four lower lines are used to control board functions four Port C Lower lines and four Port C Upper lines The 16 lines of Ports A and C are available at the P2 I O connector You can install and connect pull up or pull down resistors for these 16 lines as described below For example you may want to pull lines up for connection to switches This will pull the line high when the switch is disconnected Or you may want to pull lines down for connection to relays which control turning motors on and off These motors turn on when the digital lines controlling them are high The Port A lines of the 8255 automatically power up as inputs which can
42. ite www rtd com DM5210 analog input module D 4 RTD Embedded Technologies Inc DM210 DM5210 Board User Selected Set IRQ Source amp Channel Selected Source P7 IRQ Channel P3
43. ke sure all connections are secure External I O Connections Figure 2 1 shows the 210 5210 s P2 I O connector pinout Refer to this diagram as you make your I O connec tions Note that the 12 and 12 volt signals are available at pins 47 and 49 only if your computer supplies these voltages DM5210 analog input module 2 3 RTD Embedded Technologies Inc 12 VOLTS 12 VOLTS 5 VOLTS DIGITAL GND AIN1 DE AIN9 AIN2 OP AIN10 AIN3 OE AIN11 AIN4 DE AIN12 AINS 3 40 AIN13 AING DE AIN14 AIN7 309 AIN15 AINS 45 46 AIN16 ANALOG GND 28 ANALOG GND EXT GATE 0 ANALOG GND ANALOG GND DA ANALOG GND PA7 234 PC7 PAG CICI PC6 PA5 DE PC5 PA4 PC4 PA3 GDG res PA2 83 8 PC2 PA1 65 86 PC1 PAO 6268 PCO EXT CLK 0 T C OUT 0 EXT GATE 1 T C OUT 1 EXT CLK 1 T C OUT 2 EXT CLK 2 EXT GATE 2 Fig 2 1 P2 I O Connector Pin Assignments Connecting the Analog Inputs NOTE It is good practice to connect all unused channels to ground as shown in the following diagram Failure to do so may affect the accuracy of your results Connect the high side of the analog input to one of the analog input channels AIN1 through AIN16 and connect the low side to the corresponding dedicated ANALOG GND for the selected channel Figure 2 2 shows how these connections are made Connecting the Timer Counters and Digital I O For all of these connections the high side of an external signal source or destination device is connected to the
44. keystroke does occur the keyboard interrupts the processor and the processor gets the keyboard data places it in memory and then returns to what it was doing before it was interrupted Other common devices that use interrupts are modems disk drives and mice Your 210 5210 can interrupt the processor when a variety of conditions are met By using these interrupts you can write software that effectively deals with real world events Interrupt Request Lines To allow different peripheral devices to generate interrupts on the same computer the PC bus has eight different interrupt request IRQ lines A transition from low to high on one of these lines generates an interrupt request which is handled by the PC s interrupt controller The interrupt controller checks to see if interrupts are to be acknowledged from that IRQ and if another interrupt is already in progress it decides if the new request should supersede the one in progress or if it has to wait until the one in progress is done This prioritizing allows an interrupt to be interrupted DM5210 analog input module 4 12 RTD Embedded Technologies Inc if the second request has a higher priority The priority level is based on the number of the IRQ IRQO has the highest priority IRQ1 is second highest and so on through IRQ7 which has the lowest Many of the IRQs are used by the standard system resources IRQO is used by the system timer IRQ is used by the keyboard IRQ3 by COM I
45. l Count This mode is typically used for event counting While the timer counter counts down the output is low and when the count is complete it goes high The output stays high until a new Mode 0 control word is written to the timer counter Mode 1 Hardware Retriggerable One Shot The output is initially high and goes low on the clock pulse following a trigger to begin the one shot pulse The output remains low until the count reaches 0 and then goes high and remains high until the clock pulse after the next trigger DM5210 analog input module 4 16 RTD Embedded Technologies Inc Mode 2 Rate Generator This mode functions like a divide by N counter and is typically used to generate a real time clock interrupt The output is initially high and when the count decrements to 1 the output goes low for one clock pulse The output then goes high again the timer counter reloads the initial count and the process is repeated This sequence continues indefinitely Mode 3 Square Wave Mode Similar to Mode 2 except for the duty cycle output this mode is typically used for baud rate generation The output is initially high and when the count decrements to one half its initial count the output goes low for the remainder of the count The timer counter reloads and the output goes high again This process repeats indefinitely Mode 4 Software Triggered Strobe The output is initially high When the initial count expires the output goes low for one c
46. librates the bipolar ranges 5 10 volts Table 5 1 shows the ideal input voltage for each bit weight for all three input ranges Unipolar Calibration Two adjustments are made to calibrate the A D converter for the unipolar range of 0 to 10 volts One is the offset adjustment and the other is the full scale or gain adjustment Trimpot TR4 is used to make the offset adjust ment and trimpot TR1 is used for gain adjustment This calibration procedure is performed with the module set up for a 0 to 10 volt input range Before making these adjustments make sure that the jumpers on P5 and P6 are set for this range Use analog input channel 1 gain 1 while calibrating the module Connect your precision voltage source to channel 1 Set the voltage source to 1 22070 millivolts start a conversion and read the resulting data Adjust trimpot TR4 until it flickers between the values listed in the table at the top of the next page Next set the voltage to 9 49829 volts and repeat the procedure this time adjusting TR1 until the data flickers between the values in the table Table 5 1 A D Converter Bit Weights for All Input Ranges Ideal Input Voltage millivolts AID Bit Weight Oto 10 Volts 4095 full scale 19997 56 2048 0000 00 5000 00 1024 2500 00 2500 00 512 3750 00 1250 00 256 4375 00 625 00 4687 50 312 50 4921 88 9843 75 78 13 4960 94 9921 88 39 06 4980 47 9960 94 19 53 4990 23 9980 47 9 77 4995 1
47. ll your ISR temporarily mask out the IRQ you will be using This prevents the IRQ from requesting an interrupt while you are installing and initializing your ISR To mask the IRQ read in the current IMR at I O port 21H and set the bit that corresponds to your IRQ remember setting a bit disables interrupts on that IRQ while clearing a bit enables them The IMR is arranged so that bit 0 is for IRQO bit I is for IRQI and so on See the paragraph entitled Interrupt Mask Register IMR earlier in this discussion for help in determining your IRQ s bit After setting the bit write the new value to I O port 21H With the startup IMR saved and the interrupts on your IRQ temporarily disabled you can assign the interrupt vector to point to your ISR Again you can overwrite the appropriate entry in the vector table with a direct memory write but this is a bad practice Instead use either DOS function 25H set interrupt vector or if your compiler provides it the library routine for setting an interrupt vector Remember that vector 8 is for IRQO vector 9 is for IRQI and so on If you need to program the source of your interrupts do that next For example if you are using a programmable interval timer to generate interrupts you must program it to run in the proper mode and at the proper rate Finally clear the bit in the IMR for the IRQ you are using This enables interrupts on the IRQ Restoring the Startup IMR and Interrupt Vector Before e
48. lls you how to calibrate the A D converter gain and offset The offset and full scale performance of the module s A D converter is factory calibrated Any time you suspect inaccurate readings you can check the accuracy of your conversions using the procedure below and make adjusts as necessary Using the 5210DIAG diagnostics program is a convenient way to monitor conversions while you calibrate the module Calibration is done with the module installed in your system You can access the trimpots at the edge of the module Power up the system and let the board circuitry stabilize for 15 minutes before you start calibrating Required Equipment The following equipment is required for calibration Precision Voltage Source 10 to 10 volts Digital Voltmeter 5 1 2 digits Small Screwdriver for trimpot adjustment While not required the 5210DIAG diagnostics program included with example software is helpful when performing calibrations Figure 5 1 shows the module layout with the three trimpots used for calibration TR1 TR2 and TR4 located along the top right edge TRi TR2 TR4 X YET PEYTYEYT a CJC epg Sei Fig 5 1 Module Layout DM5210 analog input module 5 3 RTD Embedded Technologies Inc A D Calibration Two procedures are used to calibrate the A D converter for all input voltage ranges The first procedure cali brates the converter for the unipolar range 0 to 10 volts and the second procedure ca
49. lock pulse and then goes high again Counting is triggered by writing the initial count Mode 5 Hardware Triggered Strobe Retriggerable The output is initially high Counting is triggered by the rising edge of the gate input When the initial count has expired the output goes low for one clock pulse and then goes high again Digital UO The 20 available 8255 PPI based digital I O lines can be used to transfer data between the computer and external devices The digital input lines of Ports A and C can have pull up or pull down resistors installed as described in Chapter 1 DM5210 analog input module 4 17 RTD Embedded Technologies Inc Example Programs and Flow Diagrams Included with the 210 5210 is a set of example programs that demonstrate the use of many of the module s features These examples are in written in C and BASIC Also included is an easy to use menu driven diagnostics program 5210DIAG which is especially helpful when you are first checking out your module after installation and when calibrating the module Chapter 5 Before using the software included with your module make a backup copy of the disk You may make as many backups as you need C Programs These programs are source code files so that you can easily develop your own custom software for the 210 5210 In the C directory DM5210 H and DM5210 INC contain all the functions needed to implement the main C pro grams H defines the addresses and INC contains
50. nd Port C Upper 4 lines Group B Port B 8 lines and Port C Lower 4 lines Sixteen lines Port A Port C Lower and Port C Upper are brought out to the I O connector Four of Port B s lines are used to control on board functions The remaining four Port B lines PB4 PB7 are available at the pads labeled P8 on the module You can use these ports in one of these three PPI operating modes Mode 0 Basic input output Lets you use simple input and output operation for a port Data is written to or read from the specified port Mode 1 Strobed input output Lets you transfer I O data from Port A in conjunction with strobes or hand shaking signals Mode 2 Strobed bidirectional input output Lets you communicate bidirectionally with an external device through Port A Handshaking is similar to Mode 1 These modes are detailed in the 8255 Data Sheet reprinted from Intel in Appendix C Interrupts The 210 5210 has three jumper selectable interrupt sources end of convert 8254 timer counter output 2 and the external clock for timer counter 2 brought onto the module through P2 The end of convert signal can be used to interrupt the computer when an A D conversion is completed The 8254 timer counter output 2 can be used to generate an end of count interrupt The external clock 2 interrupt can be used to generate interrupts at any desired interval Chapter 4 provides some programming information about interrupts DM5210 analog in
51. nnnnnnnrrnnnnnnnnrrnnnnnnnnnrnnnnnrrnnnnnennrrnnnn 2 2V min 5 5V max Low level input voltage rrrnrrnnnnnnnnnrrrnnnrrnnnrrnnnnnnnnnrnnnnnnrnnnnnnnnnnn 0 3V min 0 8V max High level output current Isource sm e 100 pA max Low level output current Isink esesssssssseeeeneeeenen 1 7 mA max Darlington drive current I DAR seseessssssse 1 0 mA min 5 0 mA max Available on any 8 pins from port B and port C Input load current sisian painei roria aaea apena aa raaa E A a aaa Eaa a ai 10 pA Input capacitance El Me LA E 10 pF Output capacitance G OUTJEOF 1MHZ EE 20 pF Timer COoUnter 5 a aa area aa aana hamn CMOS 82C54 Optional NMOS 8254 Three 16 bit down counters binary or BCD counting Programmable operating modes 6 sees Interrupt on terminal count programmable one shot rate generator square wave rate generator software triggered strobe hardware triggered strobe Counter input source sssesseeeeeennees External clock 8 MHz max or on board 8 MHz clock Counter Outputs EE Available externally used as PC interrupts or cascaded to adjacent counter Counter gate source External gate or always enabled Miscellaneous Inputs Outputs PC bus sourced 5 volts 12 volts if supplied by computer ground Current Requirements DM210 75 mA 5 volts 12 mA 9 12 volts 28 mA 9 12 volts 83W DM5210
52. nterrupt Request LIMES etae saue ORO Ten Eet 4 12 e 8259 Programmable Interrupt Controller AA 4 13 Interrupt Mask Register IMR ciet ted e EO Et ELO ERR EGRE ERR EE e tie ERROR 4 13 End of Interrupt EOD Commande 4 13 e What Exactly Happens When an Interrupt Occurs eonornorrnvrnvrrnvnvvvrnrevneerevverererarerarsaverarnrverssnsesvesveener 4 13 Using Interrupts in Your Programs 20 cece csecesecsecesecescesecsceseeseeeseeeaeeeseseeeaecseeeaecaaecaecsasaeenaeeseenaes 4 13 e Writing an Interrupt Service Routine ISR oo eee eee eeeeceseeeeceseeeeecaeecaecasecaecsaecaeceaecnecsaecasenseeeeseeeeerens 4 13 e Saving the Startup Interrupt Mask Register IMR and Interrupt Vector eee eee eene 4 15 e Restoring the Startup IMR and Interrupt Vector oo eee eee ese cecneecseceseceeceseseceseeseceseseceeeeeeeeaeeeaeeeeens 4 15 Common Interrupt Mistakes see eter e fee asec dende ceeds PR e Ua ee EE eg 4 15 Timer Gounteirs ener dee ere p E Pe Re eg eg ep e aat 4 16 Digital V O EE 4 17 Example Programs and Flow Diagrams rervrrerrrnrrrnvrvvrrnervvrvvnnvenrnernrerneevrnvnaverrenarversvsrnersvennvevvessansvesvresvessvesssevnen 4 18 ET EE 4 18 BASIC Programs ogncenitesseptee e ee eed e nt nO e rede entitas 4 18 Flow Diagrams 2e eem RE arde Rem Pp edu d De UE Deeps 4 18 e Single Convert Flow Diagram Figure 4 3 sese eren ennen rennen entren nee 4 19 e Channel Scanning Flow Diagram Figure A A1 4 19 C
53. ou change the channel by writing a new value to the bottom four bits in the PPI Port B register BA 1 Changing this value before each Start Convert command is issued lets you take the next reading from a different channel Channel Scanning Flow Diagram Figure 4 4 Program 8255 PPI Port B out Select Channel Change Channel Start Conversion BA 8 for 12 bit BA 9 for 8 bit Check End of Convert EOC 1 Read LSB BA 9 Contains bits 0 3 of 12 bit conversion Read MSB BA 8 Contains bits 4 11 of 12 bit Stop Program conversion bits 0 7 of 8 bit conversion Fig 4 3 Single Conversion Flow Diagram DM5210 analog input module 4 19 RTD Embedded Technologies Inc This flow diagram shows you the steps for taking a single sample on a sequence of channels After programming Port B as a Mode 0 output port you select the starting channel in your sequence of channels to be scanned After making your initial channel selection you must allow for enough of a delay in your program for the selected channel to settle before starting the first A D conversion As soon as the first conversion is started you can then immediately select your next channel in the sequence Once the conversion is started the signal on the sampled channel has been locked in and you do not have to wait for an end of convert transition before programming the next channel Selecting the next channel as soon as the conversion of the previous ch
54. ple programs included with the module and the programming flow diagrams at the end of this chapter All of the pro gram descriptions in this section use decimal values unless otherwise specified The 210 5210 is programmed by writing to and reading from the correct I O port locations on the module These TO ports were defined in the previous section Most high level languages such as BASIC Pascal C and C and of course assembly language make it very easy to read write these ports The table below shows you how to read from and write to I O ports using some popular programming languages Language med wie BASIC Data INP Address OUT Address Data Tubo C Data inportb Address outportb Address Data Turbo Pascal Data Port Address Port Address Data mov dx Address mov dx Address Assembly in al dx Ge EE ou x al In addition to being able to read write the I O ports on the 210 5210 you must be able to perform a variety of operations that you might not normally use in your programming The table below shows you some of the operators discussed in this section with an example of how each is used with Pascal C and BASIC Note that the modulus operator is used to retrieve the least significant byte LSB of a two byte word and the integer division operator is used to retrieve the most significant byte MSB amp a b Cc a b c a b amp c a bl c MOD DIV AND OR a b MOD e a bDIVc a b AND c a bORc MOD AND OR
55. put module 3 4 RTD Embedded Technologies Inc CHAPTER 4 MODULE OPERATION AND PROGRAMMING This chapter shows you how to program and use your 210 5210 It provides a complete description of the I O map a detailed description of programming operations and operating modes and flow diagrams to aid you in programming The example programs included on the disk in your module package are listed at the end of this chapter These programs written in Turbo C and BASIC include source code to simplify your applications programming DM5210 analog input module 4 1 RTD Embedded Technologies Inc DM5210 analog input module 4 2 RTD Embedded Technologies Inc Defining the I O Map The I O map for the 210 5210 is shown in Table 4 1 below As shown the module occupies 12 consecutive I O port locations The base address designated as BA can be selected using DIP switch S1 as described in Chapter 1 Module Settings This switch can be accessed without removing the module from the connector S1 is factory set at 300 hex 768 decimal The following sections describe the register contents of each address used in the I O map UJ gt Table 4 1 DM210 DM5210 I O Map Address Register Description Read Function Decimal Program Port A digital output Read Port A digital input lines lines BA 0 Program channel number 8255 PPI Port B PB4 7 available for digital I O Channel Select Read Port B bits operations Program Port C digital output 8255
56. side the U S contact your local distributor DM5210 analog input module i 3 RTD Embedded Technologies Inc Module Accessories In addition to the items included in your module package RTD Embedded Technologies Inc offers a full line of software and hardware accessories Call your local distributor or our main office for more information about these accessories and for help in choosing the best items to support your module s application Application Software and Drivers Our custom application software packages provide excellent data acquisition and analysis support Use SIGNAL VIEW for real time monitoring and data acquisition and SIGNAL MATH for integrated data acquisition and sophisticated digital signal processing and analysis rtdLinx drivers provide full featured high level interfaces between the 210 5210 and custom or third party software rtdLinx source code is available for a one time nominal fee Hardware Accessories Hardware accessories for the 210 5210 include the TMX32 analog input expansion board with thermocouple compensation which can expand a single input channel on your 210 5210 to 16 differential or 32 single ended input channels the OP series optoisolated digital input boards the MR series mechanical relay output boards the OR16 optoisolated digital input mechanical relay output board the USF8 universal sensor interface with sensor excitation the TS16 thermocouple sensor board the TB50 terminal board and
57. terrupts Reading this register shows you the current settings DM5210 analog input module 4 3 RTD Embedded Technologies Inc BA 1 Port B X x x x CH3 D7 D6 D5 D4 D3 CH2 CH1 CHO BA 2 PPI Port C Digital I O Read Write Analog Input Channel Select 0000 channel 1 0001 channel 2 0010 channel 3 0011 channel 4 0100 channel 5 0101 channel 6 0110 channel 7 0111 channel 8 1000 channel 9 1001 channel 10 1010 channel 11 1011 channel 12 1100 channel 13 1101 channel 14 1110 channel 15 1111 channel 16 Transfers the two 4 bit Port C digital input and digital output data groups Port C Upper and Port C Lower between the module and an external device A read transfers data from the external device through P2 and into PPI Port C a write transfers the written data from Port C through P2 to an external device BA 3 8255 PPI Control Word Write Only When bit 7 of this word is set to 1 a write programs the PPI configuration The PPI must be programmed so that Port B is a Mode 0 output port as shown below X don t care Mode Set Flag 1 active DM5210 analog input module Mode Select 00 2 mode 0 01 2 mode 1 10 mode 2 Port A 0 output 1 input Port C Upper 0 output 1 input Group A 4 4 EE ET oe I Port C Lower 0 output 1 input Port B 0 output 1 input Mode Select 0 mode 0 1 mode
58. tetetestee t a ee i as ere eire RO eect RE coast see end 9 CHAPTER 2 MODULE INSTALLATION enses eren ern enn senso seen sone sn sessenssosessessessesees 2 1 Module EE e E 2 3 External I O Commecti ons i ette gere dte reete tre nh deepest e deret eo ottenere dote ete do Ce DR dete 2 3 Connecting the Analog Inputs 4 32 sce eene eden P EU e aee E He PHP e Pe cents 2 4 Connecting the Timer Counters and Digital HO 2 4 Running the 5210DIAG Diagnostics Program eese eren nee nee nenne tenere tree eene en enne nen 2 4 CHAPTER 3 HARDWARE DESCRIPTION eeeeee enses ense esso se en sons enses senses sensensessenses 3 1 A D Conversion Circuitry eroe mot evene deep eee 3 3 Analog Inputs eme eec e aer dei P mt e e io een 3 3 AID GOnVOerterz sce M SI eoa gue SS nd eet 3 3 WIM EL COUNTS M E utes 3 4 Digital I O Programmable Peripheral Interface seen ener enne 3 4 lure e 3 4 CHAPTER 4 MODULE OPERATION AND PROGRAMMING eene enennnnnes 4 1 Defining the O Map satse steg etate dieit erp eme p eie tege indere 4 3 BA 0 PPI Port A Digital I O Read Write eese eene ener ennnetnnr etn enne nrr enne 4 3 BA 1 PPI Port B Channel Select Read Write esses seen enne enne 4 3 BA 2 PPI Port C Digital I O Read Write AAA 4 4 BA 3 8255 PPI Control Word Write Only
59. to disable this feature and use the interrupts in the normal mode This will insure compatibility with all CPUs See chapter 4 for details on disabling the interrupt sharing circuit NOTE When you use multiple modules that share the same interrupt only one module should have the G jumper installed The rest should be disconnected Whenever you operate a single module the G jumper should be installed Whenever you operate the module with interrupt sharing disabled the G jumper should be removed EXT INT CLK IRQ STATUS INTERRUPT REGISTER INTERRUPT CLR P3 Fig 1 3 Pulling Down the Interrupt Request Line DM5210 analog input module 1 4 RTD Embedded Technologies Inc P4 8254 Timer Counter Clock Sources Factory Settings CLK0 OSC CLK1 OT0 CLK2 OT1 This header connector shown in Figure 1 4 lets you select the clock sources for the 8254 timer counters TCO TC1 and TC2 The factory setting cascades all three timer counters with the clock source for TCO being the on board 8 MHz oscillator the output of TCO providing the clock for TC1 and the output of TC1 providing the clock for TC2 You can connect any or all of the sources to an external clock input through the P2 I O connector or you can set TC1 and TC2 to be clocked by the 8 MHz oscillator Figure 1 5 shows a block diagram of the timer counter circuitry to help you with these connections NOTE When installing jumpers on this header make sure that only one jumper
60. uits It also discusses interrupts DATA 16 ANALOG INPUTS 5V 0 10V 12 BIT 16 10V PS ON BOARD HEADER INTERRUPT 4 SELECT A D CONVERTER PC BUS UO CONNECTOR SELECT ADDRESS DECODE d 5 VOLTS DC DC 15 VOLTS K CONVERTER SEN 12 VOLTS CONTROL 5 VOLTS Fig 3 1 DM210 DM5210 Block Diagram A D Conversion Circuitry The 210 5210 performs analog to digital conversions on up to 16 analog input channels The following para graphs describe the A D circuitry Analog Inputs Sixteen single ended analog input channels are available on the 210 5210 The analog input range is jumper selectable for 5 to 5 volts 10 to 10 volts or 0 to 10 volts with 35 Vdc overvoltage protection The channels are connected to a sample and hold amplifier through a multiplexing circuit The active channel is selected through software as described in Chapter 4 The S H amplifier captures and holds the input signal at a constant level while the conversion is performed ensuring that dynamic analog signals are accurately digitized This capacitive circuit quickly charges to a level corresponding to the input voltage being sampled and holds the charge for the duration of the conversion A D Converter The 12 bit A D converter when combined with the typical acquisition time of the sample and hold circuitry provides a throughput rate of up to 40 000 samples per second The A D output is a 12 bit data word Note that 8 bit conv
61. umber in large 1 letters on the outside of the package Return the package to RTD Embedded Technologies Inc 103 Innovation Blvd State College PA 16803 0906 USA DM5210 analog input module D 1 RTD Embedded Technologies Inc DM5210 analog input module D 2 RTD Embedded Technologies Inc LIMITED WARRANTY RTD Embedded Technologies Inc warrants the hardware and software products it manufactures and produces to be free from defects in materials and workmanship for one year following the date of shipment from RTD Embedded Technologies INC This warranty is limited to the original purchaser of product and is not transferable During the one year warranty period RTD Embedded Technologies will repair or replace at its option any defective products or parts at no additional charge provided that the product is returned shipping prepaid to RTD Embedded Technologies All replaced parts and products become the property of RTD Embedded Technologies Before returning any product for repair customers are required to contact the factory for an RMA number THIS LIMITED WARRANTY DOES NOT EXTEND TO ANY PRODUCTS WHICH HAVE BEEN DAMAGED AS A RESULT OF ACCIDENT MISUSE ABUSE such as use of incorrect input voltages improper or insufficient ventilation failure to follow the operating instructions that are provided by RTD Embedded Technologies acts of God or other contingencies beyond the control of RTD Embedded Technologies OR AS A RE
62. unter and a write loads the counter with a new value Counting begins as soon as the count is loaded BA 6 8254 Timer Counter 2 Read Write A read shows the count in the counter and a write loads the counter with a new value Counting begins as soon as the count is loaded BA 7 8254 Control Word Write Only Accesses the 8254 control register to directly control the three timer counters BCD Binary 0 binary 1 BCD Counter Select 00 Counter 0 01 Counter 1 10 Counter 2 Read Load 11 read back setting Counter Mode Select 000 Mode 0 event count 001 Mode 1 programmable 1 shot 00 latching operation 010 Mode 2 rate generator 01 read load LSB only 011 Mode 3 square wave rate generator 10 read load MSB only 100 Mode 4 software triggered strobe 11 read load LSB then MSB 101 Mode 5 hardware triggered strobe DM5210 analog input module 4 6 RTD Embedded Technologies Inc BA 8 Read MSB Data Start 12 Bit Conversion Read Write A read provides the MSB 8 most significant bits of the A D conversion as defined below The converted data is left justified When you are performing 8 bit conversions only the MSB must be read Writing to this address starts a 12 bit A D conversion the data written is irrelevant 12 Bit Bit11 Bit10 Bit9 Bit 8 Bit 7 Bit 6 Bit 5 Bit 4 8 Bit Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 BA 9 Read LSB Data Start 8 Bit Conversion Read Write
63. use DOS and should be avoided in your ISR The same problem of reentrancy exists for many floating point emulators as well meaning you may have to avoid floating point real math in your ISR Note that the problem of reentrancy exists no matter what programming language you are using Even if you are writing your ISR in assembly language DOS and many floating point emulators are not reentrant Of course there are ways around this problem such as those which involve checking to see if any DOS functions are currently active when your ISR is called but such solutions are well beyond the scope of this discussion The second major concern when writing your ISR is to make it as short as possible in terms of execution time Spending long periods of time in your ISR may mean that other important interrupts are being ignored Also if you spend too long in your ISR it may be called again before you have completed handling the first run This often leads to a hang that requires a reboot Your ISR should have this structure Push any processor registers used in your ISR Most C and Pascal interrupt routines automatically do this for you Put the body of your routine here Clear the interrupt bit on the 210 5210 by writing any value to BA 10 Issue the EOI command to the 8259 interrupt controller by writing 20H to port 20H Pop all registers pushed on entrance Most C and Pascal interrupt routines automatically do this for you The follo
64. ut module B 4 RTD Embedded Technologies Inc APPENDIX C COMPONENT DATA SHEETS DM5210 analog input module C 1 RTD Embedded Technologies Inc DM5210 analog input module C2 RTD Embedded Technologies Inc Intel 82C54 Programmable Interval Timer Data Sheet Reprint DM5210 analog input module C 3 RTD Embedded Technologies Inc DM5210 analog input module CA RTD Embedded Technologies Inc Intel 82C55A Programmable Peripheral Interface Data Sheet Reprint DM5210 analog input module C 5 RTD Embedded Technologies Inc DM5210 analog input module C 6 RTD Embedded Technologies Inc APPENDIX D WARRANTY AND RETURN POLICY Return Policy If you wish to return a product to the factory for service please follow this procedure Read the Limited Warranty to familiarize yourself with our warranty policy Contact the factory for a Return Merchandise Authorization RMA number Please have the following available Complete board name Board serial number A detailed description of the board s behavior List the name of a contact person familiar with technical details of the problem or situation along with their phone and fax numbers address and e mail address if available List your shipping address Indicate the shipping method you would like used to return the product to you We will not ship by next day service without your pre approval Carefully package the product using proper anti static packaging Write the RMA n
65. volts or for 5 or 10 volts Note that when you place a jumper across 20V on PS you must place the P6 jumper across 10 volts The setting cannot be used with the 20 volt input range Figure 1 6 shows the three possible input voltage configurations for P5 and P6 N N N ch oo t gt Z lt 2 lt lt 2 2 I P5 P6 P5 P6 P5 P6 Fig 1 6a Fig 1 6b Inputs Fig 1 6c Inputs Factory Setting 5V Connected for 10V Connected for 0 to 10V Fig 1 6 Analog Input Voltage Range and Polarity P5 and P6 P7 Interrupt Source Factory Setting OT2 This header connector shown in Figure 1 7 lets you select any one of three signal sources for use in generating an interrupt An interrupt source is chosen by placing a jumper across the desired pair of pins The interrupt sources available are the A D end of convert EOC the output of timer counter 2 OT2 and timer counter external clock 2 EC2 The interrupt channel for the selected source is set on P3 P7 m om SNK Fig 1 7 Interrupt Source Jumper P7 P8 8255 Port B Bits 4 7 Pads Factory Setting No Connections These four pads shown in Figure 1 8 provide easy access to the top four bits of Port Bin the 8255 PPI These bits are available to the user as digital outputs You can install a header right angle connector or use another method to connect these signals into your circuit The holes closest to the edge of the board are the ground and the holes
66. wing C and Pascal examples show what the shell of your ISR should be like In C void interrupt ISR void Your code goes here Do not use any DOS functions outportb BaseAddress 10 0 Clear 210 5210 interrupt outportb 0x20 0x20 Send EOI command to 8259 DM3210 analog input module 4 14 RTD Embedded Technologies Inc In Pascal Procedure ISR Interrupt begin Your code goes here Do not use any DOS functions Port BaseAddress 10 0 Clear 210 5210 interrupt Port 20 20 Send EOI command to 8259 end Saving the Startup Interrupt Mask Register IMR and Interrupt Vector The next step after writing the ISR is to save the startup state of the interrupt mask register and the interrupt vector that you will be using The IMR is located at I O port 21H The interrupt vector you will be using is located in the interrupt vector table which is simply an array of 256 bit 4 byte pointers and is located in the first 1024 bytes of memory Segment 0 Offset 0 You can read this value directly but it is a better practice to use DOS function 35H get interrupt vector Most C and Pascal compilers provide a library routine for reading the value of a vector The vectors for the hardware interrupts are vectors 8 through 15 where IRQO uses vector 8 IRQI uses vector 9 and so on Thus if the 210 5210 will be using IRQ3 you should save the value of interrupt vector 11 Before you insta
67. xiting your program you must restore the interrupt mask register and interrupt vectors to the state they were in when your program started To restore the IMR write the value that was saved when your program started to I O port 21H Restore the interrupt vector that was saved at startup with either DOS function 35H get interrupt vector or use the library routine supplied with your compiler Performing these two steps will guarantee that the interrupt status of your computer is the same after running your program as it was before your program started running Common Interrupt Mistakes Remember that hardware interrupts are numbered 8 through 15 even though the corresponding IRQs are numbered 0 through 7 Two of the most common mistakes when writing an ISR are forgetting to clear the interrupt status of the 210 5210 and forgetting to issue the EOI command to the 8259 interrupt controller before exiting the ISR DM5210 analog input module 4 15 RTD Embedded Technologies Inc Timer Counters An 8254 programmable interval timer provides three 16 bit 8 MHz timer counters for timing and counting functions such as frequency measurement event counting and interrupts All three timer counters are cascaded at the factory Figure 4 2 shows the timer counter circuitry 5200 UO CONNECTOR io P4 I I I I I I OSCO Oo 8 MHz l TIMER EXT CLK 0 l ECOL o PIN 394 COUNTER PIN 194 EXT GATE 0 OT0O OSCO O TIMER ECH I PIN 43

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