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1771-6.5.76, RTD Input Module User Manual

1. To Output Devices PEA za perma wO he 2 BTR 4 mrja S iii RTD Input Module 1771 IR Series B PC Processor PLC 5 40 Shown 12933 I 3 The module converts analog signals into binary or BCD format and stores theses values until the processor requests their transfer 4 When instructed by your ladder program the processor performs a read block transfer of the values and stores them in a data table 5 The processor and module determine that the transfer was made without error and that input values are within specified range 6 Your ladder program can use and or move the data if valid before it is written over by the transfer of new data in a subsequent transfer 2 2 Chapter 2 Overview of the RTD Input Module 7 Your ladder program should allow write block transfers to the module only when enabled by the operator at power up Accuracy The accuracy of the input module is described in Appendix A Getting Started Your input module package contains the following items Please check that each part is included and correct before proceeding RTD Input Module Cat No 1771 IR Series B User s Manual Input Module Field Wiring Arm User s Manual 1771 IR Series B Cat No 1771 WF 1771 6 5 76 Chapter Summary In this chapter you read about
2. HIGH H DN DATA 15 LENGTH CNTL CNTL T F0003 0000 is the address of the write block transfer data file You want to enter examine word 1 1 Press SHIFT MODE to display your ladder diagram on the industrial terminal 2 Press DD 03 0 ENTER to display the block transfer write file The industrial terminal screen should look like Figure B 2 Notice the highlighted block of zeroes This highlighted block is the cursor It should be in the same place as it appears in figure B 2 If it is not you can move it to the desired position with the cursor control keys Once you have the highlighted cursor in the right place you can go on to step 3 B 3 Appendix B Programming Examples 3 Enter the data corresponding to your bit selection in word 0 4 When you have entered your data press ENTER If you make a mistake make sure the cursor is over the word you desire to change Enter the correct data and press ENTER Figure B 2 Write Block Transfer for a PLC 3 Processor START W0003 0000 WORD 00000 00004 00010 00014 00020 0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 DATA MONITOR PROG 1 0 OFF PLC 5 Family Processors B 4 NO FORCES 1 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 W03 0 NO EDITS 2 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00
3. Chapter 3 Installing the RTD Input Module 2 Place the module in the plastic tracks on the top and bottom of the slot that guides the module into position 3 Do not force the module into its backplane connector Apply firm even pressure on the module to seat it properly 4 Snap the chassis latch over the top of the module to secure it 5 Connect the wiring arm to the module Interpreting the Indicator The front panel of the input module contains a green RUN and a red FLT fault Lights indicator Figure 3 4 At power up the green and red indicators are on An initial module self check occurs If there is no fault the red indicator turns off The green indicator will blink until the processor completes a successful write block transfer to the module If a fault is found initially or occurs later the red FLT indicator lights Possible module fault causes and corrective action are discussed in Chapter 8 Troubleshooting Figure 3 4 Diagnostic Indicators Chapter Summary In this chapter you learned how to install your input module in an existing programmable controller system and how to wire to the field wiring arm 3 6 Chapter Objectives Block Transfer Programming Module Programming In this chapter we describe Block Transfer programming Sample programs in the PLC 2 PLC 3 and PLC 5 processors Module scan time issues Your module communicates with the processor through bidirectional block transf
4. 870 C or 598 F with Overflow if customer bias has not been applied Copper 260 C or 500 F A block transfer with a word length of 00 will return with the Series A block transfer default length 14 for a write 8 for a read To access the auto calibration word the block transfer length must be set to 15 for a write and 9 for a read Auto calibration can be performed on all channels simultaneously or on selected channels In either case channels being calibrated must be connected to the precision calibration resistors The Series B module requires approximately 2 seconds to power up The red LED is illuminated and the green LED is extinguished if the watchdog timer times out This module employs a digital filter with 120dB decade rolloff from a corner frequency of 8 Hz This Series B module is NOT compatible with the 1771 EX extender board Use the 1771 EZ extender board with Series B Platinum RTD tables are based on TEC751 alpha 00385 The 1771 IR A was based on MINCO Products Inc measurements of IEC751 RTDs Appendix F Differences between Series A and Series B If the module is programmed for RTS 0 and the PLC is switched from run to program and back to run an RTS timeout is inhibited on the change from program to run In ohms mode bias is able to produce a negative result The excitation current on Series B flows out of termination A The excitation current on the series A flowed into terminatio
5. Allen Bradley programmable controller It helps you install program calibrate and troubleshoot your module You must be able to program and operate an Allen Bradley programmable controller PLC to make efficient use of your input module In particular you must know how to program block transfer instructions We assume that you know how to do this in this manual If you do not refer to the appropriate PLC programming and operations manual before you attempt to program this module In this manual we refer to The RTD input module as the input module The Programmable Controller as the controller This manual is divided into eight chapters The following chart shows each chapter with its corresponding title and a brief overview of the topics covered in that chapter Overview of the Input Module Description of the module including general and hardware features Installing the Input Module Module power requirements keying chassis location Wiring of field wiring arm Module Programming How to program your programmable controller for these modules Sample programs Module Configuration Hardware and software configuration Module write block format Module Status and Input Data Reading data from your module Module read block format Module Calibration How to calibrate your module Troubleshooting Diagnostics reported by the module Chapter 1 Using This Manual Chapter Topics Covered Appendix A
6. Channel 6 Data Auto calibration Status Word 6 1 Chapter 6 Module Status and Input Data Table 6 B Bit Word Description for RTD Input Module 1771 IR Series B Word Bit Definition Word 1 Bits 00 05 Underrange indication for each channel set when input is below the normal operating range for copper or platinum RTD Bit 00 for input 1 bit 01 for input 2 etc See Table 6 C Power up bit is set when the module is alive but not yet configured EEPROM calibration values could not be read Bits 10 15 Overrange bits are set when the input is above the normal operating range Bit 10 for input 1 bit 11 for input 2 etc See Table 6 C Bit 16 Real time sample time out bit See page 5 2 Not used Word 2 Bit 00 05 When set indicates that default bias has been subtracted from the input value Only the remainder is shown in the data word Each bit relates to a single channel bit 00 for input 1 etc Default bias is automatically applied when BCD formatted data cannot be displayed This will occur when measuring temperatures in Fahrenheit larger than 999 9 degrees The default bias value which is subtracted is 1000 0 Bits 06 07 Not used Bits 10 15 Sign bits for each channel When set indicate that a certain input is negative Bit 10 corresponds to input 1 bit 11 to input 2 etc These bits are used for BCD and signed magnitude data formats Bits 16 17 Not used Ce Words 3 8 Input data words The
7. Figure D 1 Multiple GET Instructions Mini PLC 2 and PLC 2 20 Processors Only 010 Output Image Table 012 Sennan 017 027 030 Timer Counter Accumulated 060 s Values Area 065 110 112 _ 117 130 Timer Counter Preset Values Area Output Image Table Con ytte Contains Read Enable Bit and Block Length in Binary Code Data Address Contains Module Address in BCD First Address Destination of Transferred Data Input Image Table Status Byte Contains Done Bit Storage Location Contains File Address in BCD R Read 07 Bit 012 Rung fe ___ e __ 02 120 060 aa Rung 2 a oH 012 Rung 3 02 12172 D 3 Appendix D Block Transfer Mini PLC 2 and PLC 2 20 Processors Setting the Block Length The input module transfers a specific number of words in one block length The Multiple GET Instructions number of words transferred is determined by the block length entered in the only output image table control byte corresponding to the module s address The bits in the output image table control byte bits 00 05 must be programmed to specify a binary value equal to the number of words to be transferred For example Figure D 2 shows if your input module is set up to transfer 6 words you would set bits 01 and 02 of the lower image table control byte The binary equivalent of 6 words is 000110 You would also set bit 07 when programming the module f
8. Programs for the RTD Input Module PLC 2 Family Processors Appendix Programming Examples The following are sample programs for entering data in the configuration words of the write block transfer instruction when using the PLC 2 PLC 3 or PLC 5 family processors To enter data in the configuration words follow these steps NOTE For complete programming sample refer to Figure 4 1 Example Enter the following rung for a write block transfer BTW 010 BLOCK XFER WRITE EN Power Up Bit DATAADDR 030 06 MODULE ADDR 110 110 BLOCK LENGTH 14 oN FILE 100 115 100 is the address of the write block transfer data file You want to examine configuration word 1 In RUN PROG Mode Action Result 1 Press SEARCH 8 lt data address gt Finds the block address transfer instruction 2 Press CANCEL COMMAND 3 Press DISPLAY 0 or 1 4 Press SEARCH 51 Cursor defaults to first entry in file when SEARCH 51 is pressed 5 Press INSERT Removes preceeding command Displays the file in binary or BCD On line data change Writes data to file element B 1 Appendix B Programming Examples 1 Press SEARCH 8 lt data address gt In PROG Mode Action Result Finds the block transfer instruction 2 Press CANCEL COMMAND Removes preceeding command 3 Press DISPLAY 0 or 1 Displays the file in binary or BCD 4 Press DISPLAY 001 and enter data Puts cursor on word 1 5 Press INSERT Use the
9. Specifications Your module s specifications Appendix B Programming Examples Information on BCD signed magnitude 12 bit binary and 2 s Appendix C Data Formats complement binary Appendix D Block Transfer with Mini PLC 2 How to use GET GET instructions for block transfer with Mini PLC 2 and Mini PLC 2 20 and Mini PLC 2 20 processors Appendix E 2 and 4 wire RTD Sensors Shows wiring connections for 2 and 4 wire sensors Appendix F Differences Between Series A Identifies major differences between the series A version and the and B series B version of the RTD module Warnings and Cautions This manual contains warnings and cautions Related Products WARNING A warning indicates where you may be injured if you use your equipment improperly CAUTION Cautions indicate where equipment may be damaged from misuse You should read and understand cautions and warnings before performing the procedures they precede You can install your input module in any system that uses Allen Bradley programmable controllers with block transfer capability and the 1771 I O structure Contact your nearest Allen Bradley office for more information about your programmable controllers Product Compatibility This input module can be used with any 1771 I O chassis Communication between the discrete analog module and the processor is bidirectional The processor block transfers output data through the output image table to the module a
10. Typ 0 ccc cece cee cette ene a EE Units of Measure ccc cc eee cede eeeenes bade eden eo ener Real Time Sampling 25 cicvenreseeedvcekdevesacsednids Configuring Block for a Block Transfer Write Bit Word Descriptions 0 0 0c cece eee eee Default Configuration for the RTD Input Module Chapter Summary wsco seen sek an Reus naana aaea Module Status and Input Data 2 00005 Chapter Objectives 0 0c cece eee eee eee Reading Data from the RTD Module 05 Chapter Summary 0 00 ccc cee e eee nee ee Module Calibration 0000eeeeeeeeeeeaee Chapter Objective oc nc cactoeet Phew ohes ohdegedeeedss Tools and Equipment 00 0 ccc cee ee eee Calibrating your Input Module 000000e About Auto calibration 000 0 e eee eee eee Performing Auto calibration 0c eee neces Performing Manual Calibration 000 eee eee Chapter SUMMARY lt sxe oben die deeds wis dows icel babe Troubleshooting dnc iseecaes denen aw eawedees aaa Chapter Objective 0 c cece eee eee eee Diagnostics Reported by the Module 045 Chapter Summary ec2 see sido dee va se ee ee eee ada ee ew es Specifications 2 0cseeccnensseesnnsananees Programming Examples 0200eeeeeeneeuee Sample Programs for the RTD Input Module PLC 2 Family Process
11. above procedure to enter the required words of the write block transfer instruction Be aware that the block length will depend on the number of channels selected and whether biasing and or calibration is or is not performed for example the block may contain only 1 word if no bias or calibration is performed but may contain 14 words if using 6 inputs with bias and calibration The PLC 2 family write block transfer data file should look like Figure B 1 Figure B 1 Write Block Transfer Data Transfer for a PLC 2 Family Processor DATA ADDR 030 BINARY DATA MONITOR BLOCK LENGTH 14 BLOCK XFER WRITE MODULE ADDR 110 FILE 100 115 POSITION FILE DATA 001 00000000 00000000 00000000 00000000 002 00000000 00000000 00000000 00000000 003 00000000 00000000 00000000 00000000 004 00000000 00000000 00000000 00000000 005 00000000 00000000 00000000 00000000 006 00000000 00000000 00000000 00000000 007 00000000 00000000 00000000 00000000 008 00000000 00000000 00000000 00000000 PLC 3 Family Processors Appendix B Programming Examples Following is a sample procedure for entering data in the configuration words of the write block transfer instruction when using a PLC 3 processor For a complete sample program refer to Figure 4 2 To enter data in the configuration words follow these steps Example Enter the following rung for a write block transfer BIW BLOCK XFER WRITE A a RACK 12 _ Power Up Bit ee CNTL MODULE 1
12. available and the wide variety of possible configurations you must configure your module to conform to the analog device and specific application that you have chosen Data is conditioned through a group of data table words that are transferred to the module using a block transfer write instruction You can configure the following features for the 1771 IR series B module data format RTD type units of measure C F or ohms real time sampling calibration bias Configure your module for its intended operation by means of your programming terminal and write block transfers BTW Note Programmable controllers that use 6200 software programming tools can take advantage of the IOCONFIG utility to configure this module IOCONFIG uses menu based screens for configuration without having to set individual bits in particular locations Refer to your 6200 software literature for details During normal operation the processor transfers from 1 to 14 words to the module when you program a BTW instruction to the module s address The BTW file contains configuration words bias values and calibration values that you enter for each channel When a block transfer length of 0 is programmed the 1771 IR B will respond with the Series A default of 14 5 1 Chapter 5 Module Configuration 5 2 Data Format RTD Type Units of Measure You must indicate what format will be used to read data from your module Typica
13. by an overall cable impedance of 10 ohms on a single wire This recommendation is based on considerations of signal degradation due to resistance mismatch between the three conductors within the cable Chapter 3 Installing the RTD Input Module Grounding the Input Module When using shielded cable ground the foil shield and drain wire only at one end of the cable We recommend that you wrap the foil shield and drain wire together and connect them to a chassis mounting bolt Figure 3 3 At the opposite end of the cable tape exposed shield and drain wire with electrical tape to insulate it from electrical contact Figure 3 3 Cable Grounding Vj als Ss A al Ad MA amp Ground Shield at I O chassis mounting bolt RAT 3 ae Pete leita H oon et Shield and drain twisted into single strand Field Wiring Arm 17798 Refer to Wiring and Grounding Guidelines publication 1770 4 1 for additional information Installing the Input Module When installing your module in an I O chassis 1 First turn off power to the I O chassis WARNING Remove power from the 1771 I O chassis backplane and wiring arm before removing or installing an I O module Failure to remove power from the backplane could cause injury or equipment damage due to possible unexpected operation Failure to remove power from the backplane or wiring arm could cause module damage degradation of performance or injury 3 5
14. data words must be multiplied or divided by a factor if whole numbers need to be displayed If you are reading temperature in F or C Then there is an implied decimal point XXX X after the least significant digit Resolution is 0 1 If you are reading resistance in milliohms copper RTDs BTW word 1 bit 10 1 Then there is an implied decimal point XXX XX If you are reading resistance in milliohms all other RTDs BTW word 1 bit 10 0 Multiply the data word by 30 to get the actual value in milliohms Resolution is 30 milliohms Auto calibration word Offset calibration complete Gain calibration complete Save complete EEPROM fault 6 2 Chapter Summary Chapter 6 Module Status and Input Data Word sit Definition Word 9 Bit 07 Faulty calibration no save cont Bits 10 15 Channel failed calibration Bit 10 for input 1 bit 11 for input 2 etc Table 6 C Overrange and Underrange Values Bee BIW 0 Indication Word 1 Bit 10 RTD Ohms C F Underrange Platinum lt 200 lt 328 Overange gt 600 00 gt 1598 Underrange Copper lt 328 Overrange gt 500 In this chapter you learned the meaning of the status information that the RTD input module sends to the processor 6 3 Chapter Objective Module Calibration In this chapter we tell you how to calibrate your modules Tools and Equipment In order to calibrate your input mod
15. done bit is not energized and data is not transferred to the buffer file In this case the data in the BTR file will be overwritten by data from the next BTR Rungs 2 and 3 These rungs provide for a user initiated block transfer write BTW after the module is initialized at power up Pressing the pushbutton locks out BTR operation and initiates a BTW that configures the module Block transfer writes will continue for as long as the pushbutton remains closed Rungs 4 and 5 These rungs provide a read write read sequence to the module at power up They also insure that only one block transfer read or write is enabled during a particular program scan Rungs 6 and 7 These rungs are the conditioning block transfer rungs Include all the input conditioning shown in the example program 4 3 Chapter 4 Module Programming PLC 3 Program Example Block transfer instructions with the PLC 3 processor use one binary file in a data table section for module location and other related data This is the block transfer control file The block transfer data file stores data that you want transferred to the module when programming a block transfer write or from the module when programming a block transfer read The address of the block transfer data files are stored in the block transfer control file The industrial terminal prompts you to create a control file when a block transfer instruction is being programmed The same blo
16. or economic loss can occur if procedures are not followed properly Warnings and Cautions Identify a possible trouble spot Tell what causes the trouble Give the result of improper action Tell the reader how to avoid trouble Important We recommend you frequently backup your application programs on appropriate storage medium to avoid possible data loss 1991 Allen Bradley Company Inc PLC is a registered trademark of Allen Bradley Company Inc Table of Contents Important User Information 0e0eeeeneee l Using This Manual 0000 cece eee e eee 1 1 Purpose of Manual 2 2 02cc 0ceseeeeeteee cate sees 1 1 PUGIBNCE 2 o0b eabe dive tens i m e sone nied 1 1 Vocabulary 2 0 0 nunnana ce een en eee eens 1 1 Manual Organization 0 00 c cece eee eee 1 1 Warnings and Cautions 0 0 0 c cece eee eee 1 2 Related Products 000 cscs nese ese eee eee e ens 1 2 Product Compatibility 0 0 e cece 1 2 Related Publications 00 000 cece e ene eee eens 1 3 Overview of the RTD Input Module 2 1 Chapter Objectives 2 0 cvevaidudiehasas dveiaedie nde 2 1 Module Description n on nannaa cece cee eee ees 2 1 Features of the Input Module 000 ee eee 2 1 How Analog Modules Communicate with Programmable Controllers 2 2 ACUTA CV 220 ntessiew sue iane kal eE a eat 2 3 Getting Started oon cake ck a een eda ote dewene
17. returns to continuous block transfer reads automatically 4 5 Chapter 4 Module Programming PLC 5 Program Example 4 6 The PLC 5 program is very similar to the PLC 3 program with the following exceptions You must use enable bits instead of done bits as the conditions on each rung A separate control file must be selected for each of the BT instructions Refer to Appendix B Figure 4 3 PLC 5 Family Sample Program Structure BT BTR Enable BLOCK XFER READ EN RACK X GROUP X HDN MODULE X CONTROL XXX XX HER DATA FILE XXX XX LENGTH XX CONTINUOUS N Pushbutton BTW Enable BT BLOCK XFER WRITE RACK GROUP MODULE Power up Bit CONTROL XXX XX DATA FILE XXX XX LENGTH XX CONTINUOUS N Program Action Rungs 1 and 2 At power up the program enables a block transfer read and examines the power up bit in the BTR file rung 1 Then it initiates one block transfer write to configure the module rung 2 Thereafter the program continuously reads data from the module rung 1 A subsequent BTW operation is enabled by a pushbutton switch rung 2 Changing processor mode will not initiate a block transfer write unless the first pass bit is added to the BTW input conditions Chapter 4 Module Programming Module Scan Time Scan time is defined as the amount of time it takes for the input module to read the input channels and place new data into the data buffer Scan time for
18. sample time 50msec In this chapter you learned how to configure your module s hardware condition your inputs and enter your data Chapter Objectives Reading Data from the RTD Module Module Status and Input Data In this chapter you will read about reading data from your module input module read block format Block transfer read programming moves status and data from the input module to the processor s data table in one I O scan Table 6 A The processor user program initiates the request to transfer data from the input module to the processor During normal operation the read block transfer for this module moves up to 8 words from the RTD module in one program scan The words contain module status and input data from each channel When a block transfer length of 0 is programmed the 1771 IR B will respond with the Series A default of 8 words The user program initiates the request to transfer data from the RTD module to the processor Table 6 A BTR Word Assignments for RTD Input Module 1771 IR B Decimal Bit 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0 Octal Bit 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 CL NI om ol ajloj pm RTS EEPROM Power Timeout calibration up values not readable Channel Underrange Channel Overrange Not used Channel Polarity Not used Channel Overflow Channel 1 Data Channel 2 Data Channel 3 Data Channel 4 Data Channel 5 Data
19. the functional aspects of the input module and how the module communicates with programmable controllers 2 3 Chapter Objectives Before You Install Your Input Module Electrostatic Damage Installing the RTD Input Module This chapter gives you information on calculating the chassis power requirement choosing the module s location in the I O chassis keying a chassis slot for your module wiring the input module s field wiring arm installing the input module Before installing your input module in the I O chassis you must Calculate the power requirements of all modules in each chassis Determine where to place the module in the I O chassis Key the backplane connector in the I O chassis Make connections to the wiring arm Action required Refer to Power Requirements Module Location in the I O Chassis Module Keying Connecting Wiring and Grounding Electrostatic discharge can damage semiconductor devices inside this module if you touch backplane connector pins Guard against electrostatic damage by observing the following warning CAUTION Electrostatic discharge can degrade performance or cause permanent damage Handle the module as stated below Wear an approved wrist strap grounding device when handling the module Touch a grounded object to rid yourself of electrostatic charge before handling the module Handle the module from the front away from the backplane connector Do not touch backpla
20. to avoid disconnecting your RTD wiring Offset Calibration 1 Attach the 1 00 ohm 1 resistors as shown in Figure 7 1 2 Examine word 3 channel 1 data in the read block transfer file Note the value It should be around 1 00 100 for 10 mohm resolution 33 for 30 mohm resolution 3 Examine word 9 of the write block transfer data file Bits 16 10 make up the offset correction byte Bit 17 is the sign bit 4 Subtract the data value that you noted in step 2 from 100 The difference should be within 127 to 127 If it is not the required correction is beyond the range of software calibration If the difference is within range input the difference positive or negative in binary form in bits 17 10 of word 9 in the write block transfer file For example if at 1 00 ohm word 3 of the read block transfer data file shows 147 you would subtract 147 from 100 which equals 47 You would then enter 10101111 47 in the upper byte of word 9 The leading 1 bit 17 is the polarity bit It indicates a negative correction factor That Chapter 7 Module Calibration is you want to subtract 47 counts from your input data The lower byte remains 00 during offset calibration 5 Repeat above steps for channels 2 through 6 respectively 6 Apply the values by sending a BTW to the module Gain Calibration 1 Connect the 402 00 01 resistors to the swing arm as shown in Figure 7 2 2 Place the module in platinum ohm mod
21. 000000 00000000 00000000 RUNG RM000000 3 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 MEM PROT OFF 5 Press CANCEL COMMAND This returns you to the ladder diagram The following is a sample procedure for entering data in the configuration words of the block transfer write instruction when using a PLC 5 processor For a complete sample program refer to Figure 4 3 1 Enter the following rung BTW BLOCK XFER WRITE J RACK i 0 Power Up Bit GROUP 0 MODULE 0 CONTROL N7 0 DATA FILE N7 60 LENGTH 14 N7 60 is the address of the BTW transfer file CONTINUOUS 2 Press F8 F5 and enter N7 60 to display the configuration block The industrial terminal screen should like figure B 3 Appendix B Programming Examples Figure B 3 Sample PLC 5 Data File Hexidecimal Data Address 0 1 2 3 4 5 6 7 8 9 N7 60 5141 0976 0150 0150 0150 0150 0150 0150 0000 0000 N7 70 0000 0000 0000 0000 The above data file would configure the module as follow copper RTDs on all inputs temperature scale of Fahrenheit channel 1 displayed in ohms output data in BCD format real time sampling set to a 1 second scan rate copper RTD at 25 C is 9 76 ohms all bias values set to subtract 0150 all calibration values set to 0 3 Enter the data corresponding to your bit selections 4 ESC returns you to the ma
22. ALLEN BRADLEY wy RTD Input Module Cat No 1771 IR Series B User Manual H Important User Information Because of the variety of uses for this product and because of the differences between solid state products and electromechanical products those responsible for applying and using this product must satisfy themselves as to the acceptability of each application and use of this product For more information refer to publication SGI 1 1 Safety Guidelines For The Application Installation and Maintenance of Solid State Control The illustrations charts and layout examples shown in this manual are intended solely to illustrate the text of this manual Because of the many variables and requirements associated with any particular installation Allen Bradley Company cannot assume responsibility or liability for actual use based upon the illustrative uses and applications No patent liability is assumed by Allen Bradley Company with respect to use of information circuits equipment or software described in this text Reproduction of the contents of this manual in whole or in part without written permission of the Allen Bradley Company is prohibited Throughout this manual we make notes to alert you to possible injury to people or damage to equipment under specific circumstances WARNING Tells readers where people may be hurt if procedures are not followed properly CAUTION Tells readers where machinery may be damaged
23. The number is positive if the sign bit is O and negative if the sign bit is 1 Using the signed magnitude method 0 10110 22 1 10110 22 C 2 Two s Complement Binary Appendix C Data Formats Two s complement binary is used with PLC 3 processors when performing mathematical calculations internal to the processor To complement a number means to change it to a negative number For example the following binary number is equal to decimal 22 101102 2219 First the two s complement method places an extra bit sign bit in the left most position and lets this bit determine whether the number is positive or negative The number is positive if the sign bit is 0 and negative if the sign bit is 1 Using the complement method 0 10110 22 To get the negative using the two s complement method you must invert each bit from right to left after the first 1 is detected In the above example 0 10110 22 Its two s complement would be 1 01010 22 Note that in the above representation for 22 starting from the right the first digit is a 0 so it is not inverted the second digit is a 1 so it is not inverted All digits after this one are inverted If a negative number is given in two s complement its complement a positive number is found in the same way 1 10010 14 0 01110 14 All bits from right to left are inverted after the first 1 is detected The two s complement of 0 is not fou
24. alibration open wire detection The module can be configured for 100 ohm platinum or 10 ohm copper RTDs or other sensor types such as 120 ohm nickel RTDs Temperature ranges are available in degrees C or F Values can also be measured in ohms When using 10 ohm copper RTDs it is necessary to dedicate your module for exclusive use with 10 ohm copper RTDs You can configure the module to accept signals from any combination of 100 ohm platinum and other types of non copper RTDs Both cases are determined by block transfer write BTW selection 2 1 Chapter 2 Overview of the RTD Input Module How Analog Modules The processor transfers data to and from the module using block transfer write Communicate with BTW and block transfer read BTR instructions in your ladder diagram Programmable Controllers program These instructions let the processor obtain input values and status from the module and let you establish the module s mode of operation figure 2 1 1 The processor transfers your configuration data and calibration values to the module using a block transfer write instruction 2 External devices generate analog signals that are transmitted to the module Figure 2 1 Communication Between Processor and Module EI Q BTW 1 x RTD Ole es emo oa Go Memory 6 User Program
25. ar edge of the circuit board The position of the keying bands on the backplane connector must correspond to these slots to allow insertion of the module You can key any connector in an T O chassis to receive this module except for the leftmost connector reserved for adapter or processor modules Place keying bands between the following numbers labeled on the backplane connector Figure 3 1 Between 10 and 12 Between 28 and 30 You can change the position of these bands if subsequent system design and rewiring makes insertion of a different type of module necessary Use needlenose pliers to insert or remove keying bands 3 2 Connecting Wiring Chapter 3 Installing the RTD Input Module Figure 3 1 Keying Positions for the RTD Input Module Between 10 and 12 Between 28 and 30 Keying Bands Upper Connector 12934 Connect your I O devices to the field wiring arm shipped with the module see Figure 3 2 Attach the field wiring arm to the pivot bar at the bottom of the I O chassis The field wiring arm pivots upward and connects with the module so you can install or remove the module without disconnecting the wires The wiring arms are specific to the input module The RTD input module uses field wiring arm cat no 1771 WF Use the inputs in numerical sequence from 1 to 6 Unused inputs that are left open cause the module to report an open input condition To avoid this tie all three terminals of the open channel tog
26. atinum 2 60 C OHM 0 82 Ohms User offset calibration range is 1 29 ohms maximum Series A was 3 81 ohms Offset correction is 10 2mohms bit User gain correction is now 0 00152588 LSB for a maximum of 0 193787 Multiple BTRs may occur before configuration of the module F 1 Appendix F Differences between Series A and Series B F 2 When displaying copper 1Omohm bit resolution in ohms the resistance will be provided up to 327 67 ohms at which point an overrange will occur overrange on the Series A was 20 72 ohms Platinum 30mohm bit resolution will over range at 600 00 ohms but continue to measure until the input saturates Series A was 399 99 ohms Underrange for the Series B will be 1 ohm but continue to display until the input can no longer track The Series A underranged at copper 1 17 ohms platinum 18 39 ohms The Series B continues to track beyond the under or overrange except overrange on copper which clamps at 327 67 ohms The Series A clamped the reading at the under or overrange value Open RTD detection excitation signal disconnected will flag an Overrange instead of Underrange Open RTD detection is lt 0 5 seconds Overrange will continue to function as a flag even if single channel ohms has been requested When a channel is displaying temperature and an overrange is detected BTR temperature data for that channel will be clamped at the RTD maximum temperature Platinum
27. ble calibration on any channel set 1 the corresponding bit 10 through 15 of word 15 4 Queue block transfer reads BTRs to monitor for offset calibration complete and any channels which may have not calibrated successfully Refer to Table 7 B Table 7 B Read Block Transfer Word 9 Word R E E ali al i K lii Bit Uncalibrated Uncalibrated Channels Auto Calibration Status Word 9 EEPROM BER Gain Cal Offset Cal Fault Complete Complete Complete 5 Proceed to gain calibration below Gain Calibration Calibrating gain requires that you apply 402 00 ohms across each input channel Normally all inputs are calibrated together To calibrate the gain of an input proceed as follows 1 Connect 402 00 ohm resistors across each input channel as shown in Figure 7 2 7 3 Chapter 7 Module Calibration Figure 7 2 Resistor Location for Gain Calibration Terminal Identification Channel 1 Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 Repeat for each channel 402 0 ohm Resistor B B B B B B 12935 2 Apply power to the module 3 After the connections stabilize request the gain calibration by setting bit 01 in BTW word 15 and sending a block transfer write BTW to the module Refer to Table 7 A NOTE Normally all channels are calibrated simultaneously bits 10 15 of word 15 are octal 0 To disable calibration on any channel set 1 the corresponding bit 10 through 15 of
28. ce 25 C Channel 1 Bias Channel 2 Bias Channel 3 Bias Channel 4 Bias Channel 5 Bias Channel 6 Bias Channel 1 calibration Channel 2 calibration o gt NI DO oy A ew N ak o n Channel 3 calibration R Channel 4 calibration ECE Channel 5 calibration r Channel 6 calibration 15 Auto calibration request word 5 4 Bit Word Descriptions Chapter 5 Module Configuration Bit word descriptions of BTW file words 1 configuration 2 resistance value of 10 ohm copper RTDs 3 through 8 individual channel bias values and 9 through 14 individual channel calibration words are presented below Enter data into the BTW instruction after entering the instruction into your ladder diagram Table 5 D Bit Word Definitions for RTD Input Module Word Bits Description bits 00 05 If any of these bits are set the corresponding input channel will be reported in ohms If RTDs other than 10 ohm copper or 100 ohm platinum are used you must report those channels in ohms not degrees Data format on a channel displayed in ohms will default to binary bits 06 07 Determines what units of measure the module reports Units of measure Degrees C Degrees F Not used In temperature mode 0 Entire module is platinum 1 Entire module is 10 ohm copper Enter exact value in word 2 In ohms mode 0 30mohm count resolution 1 10mohm count resolution bits 11 12 Data format bits tell module whic
29. ch is outlined in Appendix D Figure 4 1 PLC 2 Family Sample Program Structure Block Transfer Read Done Bit FILE TO FILE MOVE EN 1 COUNTERADDR XXX 17 POSITION XXX FILE LENGTH XXX Done FILE A YYYY XXXX pN FILE R XXX XXX 15 RATE PER SCAN XXX Storage Pushbutton Bit A 2 Te Block Transfer Write Storage Done Bit Pushbutton BitA 3 ____ ____YY u Block Transfer Write Storage Done Bit Bit B 4 L Block Transfer Read Storage Done Bit Power up Bit it B 5 s V A a O u Storage Enable P up Bit BitA BTR Done Bit 7 pis sae hk f BLOCK XFER READ EN DATAADDR XXX X7 Bit e MODULE ADDR RGS Done BLOCK LENGTH XX FILE XXXX XKXX CDN Y Power up Sra e Enable i i BLOCK XFER WRITE f E 1 DATA ADDR XXX Storage MODULE ADDR RGS Bit A BLOCK LENGTH XX FILE XXXX XXXX You can replace the pushbutton with a timer done bit to initiate the block transfer write on a timed basis You can also use any storage bit in memory 4 2 Chapter 4 Module Programming Program Action Rung 1 Block transfer read buffer the file to file move instruction holds the block transfer read BTR data file A until the processor checks the data integrity 1 Ifthe data was successfully transferred the processor energizes the BTR done bit initiating a data transfer to the buffer file R for use in the program 2 Ifthe data is corrupted during the BTR operation the BTR
30. ck transfer control file is used for both the read and write instructions for your module A different block transfer control file is required for every module A sample program segment with block transfer instructions is shown in Figure 4 2 and described below Figure 4 2 PLC 3 Family Sample Program Structure BTR ENABLE BLOCK XFER READ EN Block Transfer RACK XXX 12 Read Done Bit GROUP X DONE 1 MODULE X XXXX HDN DATA XXXX XXXX 15 LENGTH X PPOR CNTL XXXKXXXK TS Block Transfer BT ENABLE Pushbutton Write Done Bit BLOCK XFER WRITE EN RACK XXX 02 Powercup GROUP x DONE Bit MODULE X XXXX H DN DATA XXXX XXXX 0 LENGTH x ERROR CNTL XXXX XXXX ER Program Action At power up the user program examines the BTR done bit in the block transfer read file initiates a write block transfer to configure the module and then does consecutive read block transfers continuously The power up bit can be examined and used anywhere in the program Rungs 1 and 2 Rungs and 2 are the block transfer read and write instructions The BTR enable bit in rung 1 being false initiates the first read block transfer After the first read block transfer the module performs a block transfer write and then does continuous block transfer reads until the pushbutton is used to request another block transfer write 4 4 Chapter 4 Module Programming After this single block transfer write is performed the module
31. dder diagram program Always start with offset adjustment followed by gain adjustment Before calibrating the module you must enter ladder logic into processor memory so that you can initiate write block transfers to the module and the processor can read inputs from the module Words 9 through 14 in the write block transfer file are the module calibration words Word 9 corresponds to channel 1 word 10 to channel 2 and so on Each word is composed of two bytes the upper byte is for offset correction and the lower byte is for gain correction Refer to Table 7 C 7 5 Chapter 7 Module Calibration 7 6 Table 7 C Module Calibration Words Channel 1 Offset S Channel 2 Offset Channel 1 Gain Channel 2 Gain Channel 3 Gain Channel 4 Gain Channel 5 Gain Channel 6 Gain Enter the information for each byte in signed magnitude binary format In each byte the most significant bit bits 17 7 is a polarity bit When the polarity bit is set 1 the module anticipates a negative calibration value A negative calibration value means that your readings are too high and you want to subtract a corrective amount from that reading A positive calibration value means that your readings are too low and you want to add a corrective amount to that reading Important If you have a spare field wiring arm you may want to temporarily switch it with the module s present wiring arm You can use this spare arm for test purposes in order
32. e This provides 30 mohm resolution display 3 Examine word 3 of the read block transfer data file It should be around 13400 decimal Your actual value will be a percentage of 13400 For example if the data in word 3 is 13408 then 13400 13408 134000 0 000597 Your actual data value differs from the theoretical value at 402 0 ohms input resistance by 0 000597 or 0 0597 You can compensate for this error by entering the percentage difference in binary coded fraction form Table 7 D lists the value for bits 7 0 Table 7 D Value for Bits 7 through 0 Bit Value Bito7 Sign bit Bit 06 0 0976562 Bit 05 0 0488281 Bit 04 0 024414 Bit 03 0 012207 Bit 02 0 00610351 Bit 01 0 00305175 Bit 00 0 00152587 7 7 Chapter 7 Module Calibration Chapter Summary 7 8 You use the values that most nearly add up to the percentage that you determined in step 8 For example to attain the value of 0 0597 you need to add Bit Number Percentage 0 0488281 0 00610351 0 00305175 0 00152587 Total 0 0595 As you can see 0 0595 is smaller than 0 0597 but this value is as close as you can come using the 7 possible values listed in Table 7 D You would enter 10100111 in the lower byte of word 9 This sets bits 05 02 01 and 00 which subtracts a gain correction of 0 0595 from the actual input data value Important When you enter data in the least significant by
33. eported in Word 9 Design your program to monitor status bits in word 9 during calibration and to take appropriate action depending on your requirements You may also want to monitor these bits while troubleshooting with your industrial terminal The module sets a bit 1 to indicate it has detected one or more of the following conditions Table 8 C Status Reported in Word 13 Word Bit Condition 6 The EEPROM could not be written Channel s could not be calibrated as indicated by bits 10 through 15 respectively h 10 15 Bit 10 channel 1 through bit 16 channel 6 could not be calibrated Check field wiring arm connections and source for proper resistance Chapter Summary In this chapter you learned how to interpret the LED status indicators and troubleshoot your input module 8 3 Appendix Specifications Module Capacity Six RTD input channels Module Location 1771 I O Chassis Sensor Type 100 ohm platinum alpha 0 00385 or 10 ohm copper alpha 0 00386 Other types may be used with report in ohms only Units of measure Temperature in C Temperature in F RTD resistance in ohms 10milliohms or 30milliohms resolution Temperature Range Platinum 200 to 870 C 328 to 1598 F Copper 200 to 260 C 328 to 500 F Resistance Range 1 00 to 600 00 ohms Resolution Platinum 0 1 C 0 1 F Copper 0 3 C 0 5 F Sensor Excitation 1mA constant current source supplied by module Input I
34. ers This is the sequential operation of both read and write block transfer instructions The block transfer write BTW instruction is initiated when the analog module is first powered up and subsequently only when the programmer wants to write a new configuration to the module At all other times the module is basically in a repetitive block transfer read BTR mode The following example programs accomplish this handshaking routine These are minimum programs all rungs and conditioning must be included in your application program You can disable BTRs or add interlocks to prevent writes if desired Do not eliminate any storage bits or interlocks included in the sample programs If interlocks are removed the program may not work properly Your analog input module will work with a default configuration of all zeroes entered in the configuration block See the configuration default section to understand what this configuration looks like Also refer to Appendix B for example configuration blocks and instruction addresses to get started Your program should monitor status bits such as overrange underrange and block transfer read BTR activity The following example programs illustrate the minimum programming required for communication to take place 4 1 Chapter 4 Module Programming PLC 2 Program Example Note that PLC 2 processors that do not have the block transfer instruction must use the GET GET block transfer format whi
35. ether Wiring connections are shown in Figure 3 2 The module requires three conductor shielded cable for signal transmission from RTD devices This cable consists of three insulated conductors covered along their entire length by a foil shield and encased in plastic The shield reduces the effect of induced noise at any point along the cable In order to do this the shield must cover the enclosed wires as completely as possible 3 3 Chapter 3 Installing the RTD Input Module 3 4 Figure 3 2 Connection Diagram for RTDs Terminal Identification hannel 1 C C C C Chassis Ground A C A C A C A C A C A C 12935 Most importantly you must ground the shield at the chassis end only We recommend connecting each input cable s shield to a properly grounded common bus Refer to Appendix E for 2 wire and 4 wire RTD connections Cable impedance Since the operating principle of the RTD module is based on the measurement of resistance you must take special care in selecting your input cables Select a cable that has a consistent impedance throughout its entire length We recommend Belden 9533 or equivalent As cable length is directly related to overall cable impedance keep input cables as short as possible by locating your I O chassis as near the RTD sensors as I O module considerations permit Keep the cable free of kinks and nicks to the shielding material Maximum cable length is limited
36. eun de os 2 3 Chapter Summary 0 0 00 anaana 2 3 Installing the RTD Input Module 3 1 Chapter Objectives n n nunana 3 1 Before You Install Your Input Module annann 3 1 Electrostatic Damage nunnan cece ee etna 3 1 Power Requirements 0 000 c cece ence eee eaes 3 2 Module Location in the I O Chassis 00 00e00es 3 2 Module Keying 00 00 ccc c cece eee n eens 3 2 Connecting Wiring 25 22 sd ta eed Siew e Eee ees 3 3 Grounding the Input Module 0 eee eee 3 5 Installing the Input Module 00 ee eee aes 3 5 Interpreting the Indicator Lights 0000 ee eae 3 6 Chapter Summary 5 5 00 010 face Skee Seeds kh Stole enews 3 6 Module Programming eeeeeeeeeeneeeee 4 1 Chapter Objectives 0 0000 e eee eee eee eee 4 1 Block Transfer Programming 000 cece ee eeee 4 1 PLC 2 Program Example 0 00 0 cece eee cues 4 2 PLC 3 Program Example 000 cee ce eee e ees 4 4 PLC 5 Program Example 000 c cece eee e ees 4 6 Module Scan Time n nnana anaana 4 7 Table of Contents Chapter Summary 00 cece eee eee eee eee Module Configuration 02 eeeeeee eens Chapter Objectives 02 05 00ccscdecunee bade ewes seh ieee Configuring Your RTD Module 00 0 0 eee eaee Data Format 255 02 eindsveceate doa te aaue ee erea eee wioben RID
37. h format to use for reporting input values to processsor 4 digit BCD 2 s complement binary Signed magnitude binary Not used bits 13 17 Real time sample bits See Table 5 B Sample Time Chapter 5 Module Configuration 5 6 Default Configuration for the RTD Input Module Chapter Summary Description Word 1 cont If bit 10 is set in word 1 and temperature readings are desired word 2 must also be used Enter the exact resistance of 10 ohm RTD at 25 C in BCD Range is 9 00 to 11 00 ohms Values less than 9 00 ohms or greater than 11 00 ohms will default to 10 00 ohms Non BCD values will also default to 10 00 ohms Words 3 8 Individual channel bias words entered in BCD This value is subtracted from the channel data in the BTR The bias value is always a positive number Bias value range is 0 lt bias lt 9999 Words 9 14 Word 15 Individual channel calibration words Auto calibration request word used to automatically calibrate selected channels and save the calibration constants in EEPROM Offset calibration complete Gain calibration complete Bit 02 Save complete Bit 06 EEPROM fault Faulty calibration no save Bits 10 15 Channel failed calibration If zeroes are written to the module in all configuration positions the module will default to BCD format 100 ohm platinum RTD temperature in degrees C real time sampling inhibited
38. hassis Ground Single lead connects to terminal A Leave 1 lead open Channel 5 Channel 6 Note In this illustration Terminal A is the 1mA excitation sourcing current Terminal B is the lead compensation sense input Terminal C is common B B B B Channel 4 B B 12935 I E 3 Major Differences between Series Appendix Differences Between Series A and Series B RTD Input Modules The following is a list of major changes from Series A to Series B RTD Input Module cat no 1771 IR The customer applied 10 ohm resistance value 0 C is now 10 ohm resistance value 25 C with a range of 9 00 to 11 00 ohms a Calibration is now done automatically using the auto calibration feature or manually through programming Auto calibration is done at 1 00 ohm and 402 0 ohms Manual software calibration is done at 1 00 and 402 00 ohms not 18 83 and 375 61 ohms The module should be configured for platinum ohms display not temperature during the calibration procedure If EEPROM read of the auto calibration values fails BTR WORD 1 bit 7 is asserted RTS can be reduced to 100ms by programming RTS 1 The default RTS setting at power up is inhibited and data is available every 50ms for Series B was 300ms for Series A Backplane power is approximately 0 85A at 5V Series A was 1 0A at 5V a Accuracy specifications over RANGE and TEMPERATURE are Typical Copper 4 91 C Pl
39. he RTD Input Module This chapter gives you information on features of the input module how an input module communicates with programmable controllers The RTD input module is an intelligent block transfer module that interfaces analog input signals with any Allen Bradley programmable controllers that have block transfer capability Block transfer programming moves input data words from the module s memory to a designated area in the processor data table in a single scan It also moves configuration words from the processor data table to module memory The input module is a single slot module and requires no external power supply After scanning the analog inputs the input data is converted to a specified data type in a digital format to be transferred to the processor s data table on request The block transfer mode is disabled until this input scan is complete Consequently the minimum interval between block transfer reads 5Oms is the same as the total input update time for each analog input module The RTD input module senses up to 6 RTD signals at its inputs and converts them to corresponding temperature or resistance in 4 digit BCD or 16 bit binary format Module features include Six resistance temperature detector inputs Reports C F or ohms for 100 ohm platinum or 10 ohm copper sensors Reports ohms for other types of sensors software configurable 0 1 degree 10 milliohm input resolution auto c
40. he file address is stored in word 130 100g above the data address Output Energize Instruction 012 07 enables the block transfer read operation If all conditions of the rung are true the block transfer read enable bit 07 is set in the output image data table control byte The output image table control byte contains the read enable bit and the number of words to be transferred The output energize instruction is defined as follows 0 indicates that it is an output instruction indicates the I O rack address 2 indicates the module group location within the rack 07 indicates this is a block transfer read operation if this were a block transfer write operation 07 would be replaced by 06 D 1 Appendix D Block Transfer Mini PLC 2 and PLC 2 20 Processors D 2 Rungs 2 and 3 These output energize instructions 012 01 and 012 02 define the number of words to be transferred This is accomplished by setting a binary bit pattern in the module s output image table control byte The binary bit pattern used bits 01 and 02 energized is equivalent to 6 words or channels and is expressed as 110 in binary notation Rung Summary Once the block transfer read operation is complete the processor automatically sets bit 07 in the input image table status byte and stores the block length of the data transferred App endix D Block Transfer Mini PLC 2 and PLC 2 20 Processors
41. heir schematic representation is shown in Figure E 2 The amount of error elimination depends upon the difference between the resistance values of the lead wires The closer the resistance values are to each other the greater the amount of error that is eliminated Appendix E 2 E 2 and 4 Wire Sensors Connecting 4 Wire Sensors Figure E 2 Connections for 3 and 4 Wire Sensors 3 Wire Sensor ve Leave Open 4 Wire Sensor There are several ways to insure that the lead resistance values match as closely as possible They are use heavy gauge wire 16 18 gauge keep lead distances less than 1000 feet use quality cable that has a small tolerance impedance rating Figure E 3 shows how to connect 4 wire sensors to the field wiring arm of the RTD Input module A 4 wire sensor has two pairs of leads one pair for each resistor junction One wire of the 4 is not used it does not matter which one This leaves 3 wires one pair and one single wire You must connect the single wire to the terminal marked A You connect the remaining pair of wires to terminals B and C It doesn t matter which wire of the pair connects to terminal B and which wire connects to terminal C so long as all 3 wires are the same AWG gauge Appendix E 2 and 4 Wire Sensors Figure E 3 Connecting a 4 Wire Sensor to the Field Wiring Arm Terminal Identification Channel 1 Channel 2 Channel 3 C
42. ibration write transfer calibration words 9 through 14 must contain zeroes 7 1 Chapter 7 Module Calibration Performing Auto calibration Calibration of the module consists of applying 1 00 ohm resistance across each input channel for offset calibration and 402 00 ohm across each input channel for gain correction Offset Calibration Normally all inputs are calibrated together To calibrate the offset of an input proceed as follows 1 Connect 1 00 ohm resistors across each input channel as shown in Figure 7 1 Figure 7 1 Resistor Location for Offset Calibration Terminal Identification Repeat for Channel 1 each channel 1 00 ohm Resistor Channel 2 Channel 3 Channel 4 Channel 5 Channel 6 B B B B B B 12935 2 Apply power to the module 3 After the connections stabilize request the offset calibration by setting bit 00 in block transfer write word 15 and sending a block transfer write to the module Refer to Table 7 A 7 2 Chapter 7 Module Calibration Table 7 A Write Block Transfer Word 15 Word Bit 17 16 E 14 13 12 11 10 o7 06 os os os 02 01 00 Inhibit Calibration on Channel Requested Auto Calibration Word 15 Set Requested Requested Requested these 51413 Set these bits to 0 Gain Cal Offset Cal bits to 0 NOTE Normally all channels are calibrated simultaneously bits 10 15 of word 15 are octal 0 To disa
43. in menu B 5 Appendix Data Table Formats 4 Digit Binary Coded Decimal The 4 digit BCD format uses an arrangement of 16 binary digits to represent a BCD 4 digit decimal number from 0000 to 9999 figure C 1 The BCD format is used when the input values are to be displayed for operator viewing Each group of four binary digits is used to represent a number from 0 to 9 The place values for each group of digits are 2 21 22 and 23 Table C A The decimal equivalent for a group of four binary digits is determined by multiplying the binary digit by its corresponding place value and adding these numbers Figure C 1 4 Digit Binary Coded Decimal 0X 23 0 ox 0X21 0 1X20 1 0X23 0 ox2 a 1X2 2 0X 20 0X23 0 0X 22 0 ixa 1X20 1 1X23 8 0X22 0 oxat off 1X20 1 pCO 7 A SS 1 2 3 9 C 1 Appendix C Data Formats Table C A BCD Representation Place Value Decimal 23 8 2 4 21 2 29 1 Equivalent Signed magnitude Binary Signed magnitude binary is a means of communicating numbers to your processsor It should be used with the PLC 2 family when performing computations in the processor It cannot be used to manipulate binary 12 bit values or negative values Example The following binary number is equal to decimal 22 101102 2210 The signed magnitude method places an extra bit sign bit in the left most position and lets this bit determine whether the number is positive or negative
44. lly BCD is selected with PLC 2 processors and binary also referred to as integer or decimal is selected with PLC 3 and PLC 5 processors See Table 5 A and Appendix C for details on Data Format Table 5 A Selecting Format for Reading Data Decimal Bit 10 Decimal Bit 9 Octal Bit 12 Octal Bit 11 Data Format RTD Temperature Range Platinum 200 to 870 C 328 to 1598 F Underrange i 328 Overange 600 00 870 1598 200 to 260 C 328 to 500 F 328 500 Copper Overrange The units of measure reported by the RTD module are selected by setting bits 06 07 in BTW word 1 Units of Measure Degrees C Degrees F Ohms Not used 1 If any of bits 0 5 are set 1 the corresponding input channel will be reported in ohms Real Time Sampling Chapter 5 Module Configuration The real time sampling RTS mode of operation provides data from a fixed time period for use by the processor RTS is invaluable for time based functions such as PID and totalization in the PLC It allows accurate time based calculations in local or remote I O racks In the RTS mode the module scans and updates its inputs at a user defined time interval AT instead of the default interval The module ignores block transfer read BTR requests for data until the sample time period elapses The BTR of a particular data set occurs only once at the end of the sample period and subsequent requests f
45. n A Systems wired according to the IR User s Manual will work without modification presuming the transducer is polarity insensitive Allowable ambient temperature change to maintain accuracy is 1 C min F 3 A Accuracy _2 3 auto calibration gain 7 3 offset 7 2 performing _7 2 saving calibration values _7 5 B Bblock transfer read BTR word assignments 6 1 block transfer programming 4 1 block transfer read 6 1 bit word assignments _6 2 block transfer write configuration block 5 4 BTR word 9 7 3 BTW word 15 7 3 C cable length maximum _3 4 calibration auto calibration 7 1 tools 7 1 types of 7 1 words 7 6 communication with programmable controllers 2 2 Compatibility use of data table 1 3 configuration features _5 1 Configuring your module default for 1771 IR 5 6 configuring your module 5 1 bit word descriptions _5 5 word descriptions 5 4 contents what your package contains _2 3 D data format 5 2 data formats 2 s complement binary _C 3 4 digit binary coded decimal _C 1 signed magnitude binary _C 2 Index default configuration 5 6 all zeroes 4 1 diagnostic indicators 3 6 diagnostics indicators _8 1 reported by module 8 1 words reported 8 2 differences between series A and series B E i E electrostatic damage _3 1 F field wiring arm _3 3 catalog number 3 3 G grounding 3 5 installation module _3 5 K keying band
46. nd since no first 1 is ever encountered in the number The two s complement of 0 then is still 0 C 3 Multiple GET Instructions Mini PLC 2 and PLC 2 20 Processors Appendix Block Transfer Mini PLC 2 and PLC 2 20 Processors Programming multiple GET instructions is similar to block format instructions programmed for other PLC 2 family processors The data table maps are identical and the way information is addressed and stored in processor memory is the same The only difference is in how you set up block transfer read instructions in your program For multiple GET instructions individual rungs of ladder logic are used instead of a single rung with a block transfer instruction A sample rung using multiple GET instructions is shown in Figure D 1 and described in the following paragraphs Rung 1 This rung is used to set four conditions Examine On Instruction 113 02 This is an optional instruction When used block transfers will only be initiated when a certain action takes place If you do not use this instruction block transfers will be initiated every I O scan First GET Instruction 030 120 identifies the module s physical address 120 by rack group and slot and where in the accumulated area of the data table this data is to be stored 030 Second GET Instruction 130 060 indicates the address of the first word of the file 060 that designates where the data will be transferred T
47. nd block transfers input data from the module through the input image table The module also requires an area in the data table to store the read block and write block data I O image table use is an important factor in module placement and addressing selection The module s data table use is listed in the following table Related Publications Chapter 1 Using This Manual Table 1 A Compatibility and Use of Data Table Use of Data Table Compatibility catalog Input Output Read Write umDer Image Image Block Block Addressing Chassis Bits Bits Words Words 1 2 slot 1 slot 2 slot Series 1771 IR Series B A Compatible with 1771 A1 A2 A4 chassis B Compatible with 1771 A1B A2B A3B A4B chassis Yes Compatible without restriction No Restricted to complementary module placement You can place your input module in any I O module slot of the I O chassis You can put two input modules in the same module group an input and an output module in the same module group Do not put the module in the same module group as a discrete high density module unless you are using 1 or 1 2 slot addressing Avoid placing this module close to AC modules or high voltage DC modules For a list of publications with information on Allen Bradley programmable controller products consult our publication index SD499 Chapter Objectives Module Description Features of the Input Module Chapter Overview of t
48. ne connector pins Keep the module in its static shield bag when not in use or during shipment 3 1 Chapter 3 Installing the RTD Input Module Power Requirements Your module receives its power through the 1771 I O chassis backplane from the chassis power supply The maximum drawn by the RTD module from this supply is 850mA 4 2 Watts Add the listed value to the requirements of all other modules in the I O chassis to prevent overloading the chassis backplane and or backplane power supply Module Location in the Place your module in any slot of the I O chassis except for the extreme left slot 1 0 Chassis This slot is reserved for processors or adapter modules Group your modules to minimize adverse affects from radiated electrical noise and heat We recommend the following Group analog input and low voltage DC modules away from AC modules or high voltage DC modules to minimize electrical noise interference Do not place this module in the same I O group with a discrete high density T O module when using 2 slot addressing This module uses a byte in both the input and output image tables for block transfer After determining the module s location in the I O chassis connect the wiring arm to the pivot bar at the module s location Module Keying Use the plastic keying bands shipped with each I O chassis for keying the I O slot to accept only this type of module The input module is slotted in two places on the re
49. ntains data polarity and overflow information Words 3 through 8 are data words 8 1 Chapter 8 Troubleshooting Table 8 A shows LED indications and probable causes and recommended actions to correct common faults Table 8 A Troubleshooting Chart for the RTD Input Module 1771 IR B Indication Probable Cause Recommended Action Both LEDs are OFF No power to module Check power to I O chassis Recycle as necessary Possible short on the module Replace module LED driver failure Red FLT LED ON and Microprocessor oscillator or EPROM failure Replace module Green RUN LED is ON Red FLT LED ON If immediately after power up indicates RAM or Replace module EPROM failure If during operation indicates possible Replace module microprocessor or backplane interface failure Green RUN LED is flashing Power up diagnostics successfully completed Normal operation If LED continues to flash and write block transfers Check ladder logic program If correct replace module BTW cannot be accomplished you have a possible interface failure 1 When red LED is on the watchdog timer has timed out and backplane communications are terminated Your user program should monitor communication Status Reported in Words 1 and 2 Design your program to monitor status bits in words 1 and 2 and to take appropriate action depending on your application requirements You may also want to monitor these bits while troubleshooting with your indust
50. or block transfer read operations Bit 06 is used when block transfer write operations are required D 4 Appendix D Block Transfer Mini PLC 2 and PLC 2 20 Processors Figure D 2 Setting Block Length Multiple GET Instructions only Block Transfer Read Enable Bit Read 6 Words from Module For Block Transfer Active Operations Only 010 Data Table oun Image Table Control Byte Contains Read 012 Enable Bit and Block Length in Binary Code Control 017 027 Data Address 0307 Contains Module Address in BCD Number of Words to Binary Bit Pattern Transfer Lower Output Image Table Byte Default 1 12713 D 5 About 2 and 4 Wire Sensors Appendix 2 and 4 Wire RTD Sensors You can connect 2 wire and 4 wire sensors to the RTD module Before we show you how to do this let s examine the differences between 2 3 and 4 wire sensors A 2 wire sensor is composed of just that a sensor and 2 lead wires Its schematic representation is shown in Figure E 1 Figure E 1 Connections for a 2 Wire Sensor 12950 I A sensor requires at least three leads to compensate for lead resistance error that is an error caused by resistance mismatch between the lead wires Therefore a 2 wire sensor cannot provide compensation for error caused by lead wire resistance We do not recommend that you use 2 wire sensors Three wire and 4 wire sensors compensate for lead resistance error T
51. or transferred data are ignored by the module until a new data set is available If a BTR does not occur before the end of the next RTS period a time out bit is set in the BTR status area When set this bit indicates that at least one data set was not transferred to the processor The actual number of data sets missed is unknown The time out bit is reset at the completion of the BTR Set appropriate bits in the BTW data file to enable the RTS mode You can select RTS periods ranging from 100 milliseconds msec to 3 1 seconds in increments of 100msec Refer to Table 5 B below for actual bit settings Note that the default mode of operation is implemented by placing all zeroes in bits 13 through 17 In default mode the sample time period is 50msec and the RTS time out is inhibited Note that binary representation of the RTS bit string is the RTS period X 100msec For example 900msec 01001 9 X 100msec Table 5 B Bit Settings for the Real Time Sample Mode Decimal Bits Octal Bits Important Use decimally addressed bit locations for PLC 5 processors 5 3 Chapter 5 Module Configuration Configuring Block for a The complete configuration block for the block transfer write to the module is Block Transfer Write defined in Table 5 C below Table 5 C Configuration Block for RTD Input Module Block Transfer Write Word Sample Time Data RTD Units of Single channel in ohms for RTS Format Type Measure 10 ohm resistan
52. ors 0 0 c eee ee eee e ees PLC 3 Family Processors 00 cc eee ce eee eeees PLC 5 Family Processors 0 0 cece eee eee eees S N on g _ on Eee on ere SEREREK O1 A O N N N Sa e gt oa o gt ez g _ PA a lu oo N Li h oie Da h lh ie the ico jon N i h ee o gt a y h gJ n SEE io oJ D Table of Contents Data Table Formats 200000eeeeeeeeeeeaes 4 Digit Binary Coded Decimal BCD 4 Signed magnitude Binary 0000 cece eee eens Two s Complement Binary 000 cece eee eens Block Transfer Mini PLC 2 and PLC 2 20 Processors Multiple GET Instructions Mini PLC 2 and PLC 2 20 Processors Setting the Block Length Multiple GET Instructions only 2 and 4 Wire RTD Sensors 2eeeeeeeeeees About 2 and 4 Wire Sensors 00ee eee eeeeee Connecting 4 Wire Sensors 00 cece eee eens Differences Between Series A and Series B RTD Input Modules 00 cee ee eee eeee Major Differences between Series 00 00ee0ee PRR Co N oO i a oO o gt m 1 k m m Po TI m Purpose of Manual Audience Vocabulary Manual Organization Chapter Using This Manual This manual shows you how to use your RTD input module with an
53. rial terminal The module sets a bit 1 to indicate it has detected one or more of the following conditions Table 8 B Status Reported in Words 1 and 2 Indication Data underrange Bit 05 corresponds to channel 6 bit 04 corresponds to channel 5 and so on If input connections and resistances are correct this status may indicate failed communications between the channel and microprocessor If all channels are underrange a blown fuse or failed dc dc converter may be the cause Successful power up and module is waiting for configuration data Bit 06 is reset after the first successful block transfer write 07 EEPROM calibration constants could not be read The module will continue to operate but readings may be inaccurate 8 2 ET Cla Troubleshooting Indication Word 1 cont 10 15 Data overrange Bit 15 corresponds to channel 6 bit 14 corresponds to channel 5 and so on If input connections and resistances are correct this status may indicate a failed RTD functional analog block RTD FAB 16 RTS timed out The module updated its inputs before the processor read them Not used Indicates that the default bias of 1000 0 has been subtracted from the measured value If sending binary data no overflow occurs unless there is a hardware malfunction Not used Data sign bits formatted for BCD or signed magnitude Bit 10 corresponds to channel 1 bit 11 to channel 2 and so on r Not used Status R
54. s location 3 2 keying your module 3 2 manual calibration gain 7 7 offset _7 6 performing _7 5 module description 2 1 module location _3 2 0 overrange and underrange values 6 3 Index P Power requirements 3 2 pre installation considerations _3 1 programming using 6200 software 5 1 with multiple GETs _D 1 programming example PLC 2 4 2 PLC 3 4 4 PLC 5 4 6 programs sample PLC 2 B 1 PLC 3 B 3 PLC 5 B 4 R real time sampling _5 3 bit settings _5 3 resistance cable impedance 3 4 RTD input module features 2 1 S scan time _4 7 sensors about 2 and 4 wire _E 1 connecting 4 wire _E 2 specifications A 1 error summary A 2 T troubleshooting table 8 2 types of RTDs 5 2 U units of measure 5 2 W Wiring connections 3 wire cable 3 3 wiring connections 3 3 ALLEN BRADLEY WO 934 ROCKWELL INTERNATIONAL COMPANY With offices in major cities worldwide WORLD EUROPE MIDDLE HEADQUARTERS EAST AFRICA Allen Bradley HEADQUARTERS 1201 South Second Street Allen Bradley Europa B V Milwaukee WI 53204 USA Amsterdamseweg 15 Tel 414 382 2000 1422 AC Uithoorn Telex 43 11 016 The Netherlands FAX 414 382 4444 Tel 31 2975 60611 Telex 844 18042 FAX 31 2975 60222 Publication 1771 6 5 76 March 1991 As a subsidiary of Rockwell International one of the world s largest technology companies Allen Bradley meets today s challenges of ind
55. solation Dielectric Test 1000V peak channel to channel channel to backplane for 1 second Common Mode Rejection 120db 60Hz up to 1000V peak Common Mode Impedance Greater than 10 megohms Normal Mode Rejection 60db 60Hz Input Overvoltage Protection 120V rms continuous Open RTD Response Time Open excitation terminal A to overrange lt 0 5sec Open common terminal C to underrange lt 0 5sec Open sense terminal B drift high Scan Time all 6 channels 50ms Environmental Conditions Operating Temperature 0 to 60 C 32 to 140 F Rate of Change Ambient changes greater than 1 0 C minute may temporarily degrade performance during periods of change Storage Temperature 40 to 85 C 40 to 185 F Relative Humidity 5 to 95 noncondensing Backplane Power Consumption 4 25W maximum 0 85A at 5V Keying Between 10 and 12 Between 28 and 30 Field Wiring Arm Cat No 1771 WF Appendix A Specifications Table A A 1771 IR Series B Error Summary Based on Temperatures above 200 C Error Calibration Drift RTD Type Range Temperature 25 C C C or OF F over range Copper 200 to 260 C 328 to 500 F 0 344 C 0 564 F 0 1306 Platinum 200 to 870 C 328 to 1598 F 0 100 C 0 152 F 0 0717 Table A B 1771 IR Series B Resistance Error Summary RTD Type Resistance Error 25 C Resistance Drift over range Ohm C Copper 0 074 ohm 0 0213 Platinum 0 075 ohm 0 0213 A 2 Sample
56. te remember to reenter the data in the most significant byte in the word If you don t the data in the MSB is lost 4 Repeat above steps for channels 2 through 6 5 Apply the values by sending a BTW to the module In this chapter you learned how to calibrate your input module Chapter Objective Diagnostics Reported by the Module Troubleshooting We describe how to troubleshoot your module by observing LED indicators and by monitoring status bits reported to the processor At power up the module momentarily turns on both indicators as a lamp test then checks for correct RAM operation a EPROM operation EEPROM operation a valid write block transfer with configuration data Thereafter the module lights the green RUN indicator when operating without fault or lights the red fault FLT indicator when it detects fault conditions If the red FLT indicator is on block transfer will be inhibited The module also reports status and specific faults if they occur in every transfer of data to the PC processor Monitor the green and red LED indicators and status bits in word 1 of the BTR file when troubleshooting your module Figure 8 1 LED Indicators Green RUN LED Red Fault FLT LED This module uses a read block transfer to transmit data and to monitor module and data status Word 1 of the read block transfer data file contains module status power up and data out of range information Word 2 co
57. ule you will need the following tools and equipment Tool or Equipment Model Type Available from Industrial Terminal and Programming terminal for A B Cat No 1770 T3 or Cat No Allen Bradley Company Interconnect Cable family processors 1784 145 T50 etc Highland Heights OH Precision Resistors 1 00 ohm 1 quantity of 6 CMF 65 0010 F T 0 Dale 402 0 ohm 0 01 quantity of 6 MAR6 T16 402 01 TRW Calibrating your Input You must calibrate the module in an I O chassis The module must Module communicate with the processor and industrial terminal Before calibrating your module you must enter ladder logic into the processor memory so that you can initiate BTWs to the module and the processor can read inputs from the module Calibration can be accomplished using either of two methods auto calibration manual calibration About Auto calibration Auto calibration calibrates the input by generating offset and gain correction values and storing them in EEPROM These values are read out of EEPROM and placed in RAM memory at initialization of the module The auto calibration routine operates as follows Whenever a block transfer write BTW is performed to the module any time after the module has been powered up it interrogates word 15 for a request for auto calibration The request can be for the following offset calibration gain calibration save operation save to EEPROM When using auto cal
58. ustrial automation with over 85 years of practical plant floor experience More than 13 000 employees throughout the world design manufacture and apply a wide range of control and automation products and supporting services to help our customers continuously improve quality productivity and time to market These products and services not only control individual machines but integrate the manufacturing process while providing access to vital plant floor data that can be used to support decision making throughout the enterprise ASIA PACIFIC CANADA LATIN AMERICA HEADQUARTERS HEADQUARTERS HEADQUARTERS Allen Bradley Hong Kong Allen Bradley Canada Allen Bradley Limited Limited 1201 South Second Street Room 1006 Block B Sea 135 Dundas Street Milwaukee WI 53204 USA View Estate Cambridge Ontario NIR Tel 414 382 2000 28 Watson Road 5X1 Telex 43 11 016 Hong Kong Canada FAX 414 382 2400 Tel 852 887 4788 Tel 519 623 1810 Telex 780 64347 FAX 519 623 8930 FAX 852 510 9436 P N 955109 26 Printed in USA
59. word 15 4 Queue BTRs to monitor for gain calibration complete and channels which may not have calibrated successfully 7 4 Performing Manual Calibration Chapter 7 Module Calibration Save Calibration Values If any uncalibrated channel bits bits 10 15 of BTR word 9 are set a save cannot occur Auto calibration should be performed again starting with offset calibration If the module has a faulty channel the remaining functioning channels can be calibrated by inhibiting calibration on the faulty channel The module can be run with the new calibration values but will lose them on power down To save these values proceed as follows 1 Request a save to EEPROM by setting bit 02 in BTW word 15 and sending the BTW to the module Refer to Table 7 A 2 Queue BTRs to monitor for save complete EEPROM fault and calibration fault An EEPROM fault indicates a nonoperative EEPROM a calibration fault indicates at least one channel was not properly offset or gain calibrated and a save did not occur Note During normal operation make sure bits 00 01 and 02 of BTW word 15 are zero 0 You calibrate each channel by applying a precision resistance across each channel comparing correct with actual results and entering correction into the corresponding calibration word for that channel The correction takes affect after it is transferred to the module by the corresponding BTW instruction in your la
60. your module is shown in Figure 4 4 The following description references the sequence numbers in Figure 4 4 Following a block transfer write 1 the module inhibits communication until after it has configured the data and loaded calibration constants 2 scanned the inputs 3 and filled the data buffer 4 Write block transfers therefore should only be performed when the module is being configured or calibrated Any time after the second scan begins 5 a BTR request 6 can be acknowledged When operated in real time sample mode RTS 00 a BTR may occur at any time after 4 When operated in RTS T a BTR will be waived until T milliseconds at which time 1 BTR will be released Figure 4 4 Block Transfer Time End of Block Module available Transfer to perform block Write transfer Block baa Configure 1st Scan 2nd Scan 3rd Scan i Time i Time 1 2 3 4 5 6 7 8 9 Internal Scan time 50msec T 100ms 200ms 300ms 3 1sec Chapter Summary In this chapter you learned how to program your programmable controller You were given sample programs for your PLC 2 PLC 3 and PLC 5 family processors You also read about module scan time 4 7 Chapter Objectives Configuring Your RTD Module Module Configuration In this chapter you will read how to configure your module s hardware condition your inputs and enter your data Because of the many analog devices

1771-6.5.76, RTD Input Module User Manual

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