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Encoder/Counter Modules

1. No 1771 UM006B EN P Date June 2002 PartNo 957678 18 Check Problem s Type Describe Problem s Internal Use Only Technical Accuracy text illustration Completeness _ procedure step illustration definition info in manual What information is missing L example L guideline L feature accessibility explanation other _ info not in manual Clarity What is unclear Sequence What is not in the right order L Other Comments Use back for more comments Your Name Location Phone Return to Marketing Communications Allen Bradley Co 1 Allen Bradley Drive Mayfield Hts OH 44124 6118 Phone 216 646 3176 216 646 4320 Publication ICCG 5 21 May 1990 PN 955107 82 l 2 Other Comments PLEASE FOLD HERE m oL DENN POSTAGE WILL BE PAID BY THE ADDRESSEE 6 Rockwell Automation Allen Bradley TECHNICAL COMMUNICATION 1 ALLEN BRADLEY DR MAYFIELD HEIGHTS OH 44124 9705 Publication 1771 UM006B EN P June 2002 NO POSTAGE NECESSARY IF MAILED PLEASE REMOVE Support Services At Allen Bradley customer service means experienced representatives at Customer Support Centers in key cities throughout the world for sales service and support Our value added services include Technical Support e SupportPlus programs e telephone support and 24 hour emergency hotline e software and documentation updates
2. O 01 2346 EE Programming E Options Switch Assembly SW 1 N A Input Configuration Switch Assembly SW 2 15947 Publication 1771 UM006B EN P June 2002 2 8 Preliminary Adjustments Publication 1771 UM006B EN P June 2002 3 Set the switches of SW 1 Table 2 E according to the desired programming options The settings for the count resolution switches times 1 2 or 4 do not matter if the counter mode has been selected The tip of a ball point pen can be used to set the rocker arm of a switch Do not use a pencil because the point can break off and jam the switch 4 Set the three switches of SW 2 Table 2 E according to the input configurations that have been chosen 5 Replace the component cover and tighten the screws Table 2 E Programming Option Switch Assembly SW 1 5 Single See Table 2 B Encoder On Transfer Multiplier for Mode Binary Count Resolution Off Block Counter Transfer Mode BCD Chapter 3 Installation Environment and Enclosure ATTENTION Environment and Enclosure This equipment is intended for use in a Pollution Degree 2 industrial environment in overvoltage Category II applications as defined in IEC publication 60664 1 at altitudes up to 2000 meters without derating This equipment is considered Group 1 Class A industrial equipment according to IEC CISPR Publication 11 Without appropriate precautions there
3. Output Word Written to Module 16 bits ee ee Encoder Counter Module A in Rack No 1 eod Module Group No 6 TERESE bdo p ok mW d gt LO qood Xy d d d gt 1 1 1 1 bou Xo oue NP od a oe Ri gt Output T Word 016 mpu ord 116 e Publication 1771 UM006B EN P June 2002 Input Word Read from Module 16 Bits 15955 The input image table word the means for reading data from the module is updated automatically by the processor each I O scan To examine the input status word from the module the program only needs to examine the word stored at the input image table location corresponding to the placement of the encoder counter module The output image table word the means for writing data to the module is sent by the processor automatically each I O scan In applications where only the output control word is used this word can be stored directly in the output image table location corresponding to the placement of the encoder count module Section titled Example Rungs No Preset Words Used shows the type of program needed for this type of communication Single Transfer Programming 5 7 However in some applications one or both preset words must be used Here the complication involving the output image ta
4. a Allen Bradley Encoder Counter Modules User Cat Nos 1771 14 and 1771 IK M a n u al DeviceNet DeviceNetManager and RediSTATION are trademarks of Allen Bradley Company Inc PLC PLC 2 PLC 3 and PLC 5 are registered trademarks of Allen Bradley Company Inc Windows is a trademark of Microsoft Microsoft is a registered trademark of Microsoft IBM is a registered trademark of International Business Machines Incorporated other brand and product names are trademarks or registered trademarks of their respective companies Preface Objectives Chapter Appendix Audience Vocabulary What This Manual Contains 1 2 3 4 5 6 7 A Conventions Single Transfer Programming Block Transfer Programming Preface Using This Manual Read this preface to familiarize yourself with this manual and to learn how to use it properly and efficiently We assume that you have previously used an Allen Bradley programmable controller that you are familiar with its features and that you are familiar with the terminology we use If not read the user manual for your processor before reading this manual In this manual we refer to e the individual encoder counter module as the module e the programmable controller as the controller or the processor The contents of this manual are as follows Title What s Covered Introduction General overview of the modules Preliminary Adjustments Se
5. e technical subscription services Engineering and Field Services application engineering assistance e integration and start up assistance e field service e maintenance support Technical Training e lecture and lab courses self paced computer and video based training job aids and workstations e training needs analysis Repair and Exchange Services e your only authorized source e current revisions and enhancements e worldwide exchange inventory e local support Publication 1771 UM006B EN P June 2002 www rockwellautomation com Power Control and Information Solutions Headquarters Americas Rockwell Automation 1201 South Second Street Milwaukee WI 53204 2496 USA Tel 1 414 382 2000 Fax 1 414 382 4444 Europe Middle East Africa Rockwell Automation Vorstlaan Boulevard du Souverain 36 1170 Brussels Belgium Tel 32 2 663 0600 Fax 32 2 663 0640 Asia Pacific Rockwell Automation Level 14 Core F Cyberport 3 100 Cyberport Road Hong Kong Tel 852 2887 4788 Fax 852 2508 1846 Publication 1771 UM006B EN P June 2002 PN957678 18 Supersedes publication 1771 6 5 6 1988 and 1771 6 5 6 RN1 November 1995 Copyright 2002 Rockwell Automation Inc Printed in USA
6. Preset 00 Word 1 030 203 053 012 Output 5 eH G PUT Preset 00 Word 2 03015 030 Reset j 1 Scan Counter El For the PLC processor values of constants would be 003 in rung 4 005 in rung 5 Publication 1771 UM006B EN P June 2002 15959 Single Transfer Programming 5 13 The following assumptions are made for this sample program e Encoder counter module is in I O rack 1 module group 2 e Output control word is stored in word 051 Preset words 1 and Z2 are stored in words 052 and 053 respectively e The scan counter is recycled as shown in rung 6 This allows continuous update of the module should output values be changed by the program For this example it is assumed that the bit patterns of the output words are set up elsewhere in the program Publication 1771 UM006B EN P June 2002 5 14 Single Transfer Programming Publication 1771 UM006B EN P June 2002 General Output Words Block Transfer Chapter 6 Block Transfer Programming Block transfer programming is available with all Allen Bradley processors that use the 1771 I O structure Block transfer is specifically intended for use with I O modules such as the encoder counter module that perform more complex operations than simple on off input sensing or output switching For the operation of such modules multiple words of data must be transferred to or from the processor Block transfer can be particularly useful wit
7. cannot be energized With bit 12 set to 1 the module can energize its output terminals based on a comparison of its accumulated count and preset values set by the program Bits 10 and 11 are termed function control bits These bits control module function in both encoder and counter modes They permit the counting operation of the module to be enabled or reset by the program The table in Figure 5 1 shows the bit settings for each function Bit 07 is the home latch enable bit The module resets the count to zero only when all three of these conditions are true Home latch enable bit bit 07 is set to 1 e Marker input is high e Home limit switch is closed limit switch LED is on The count remains at zero until one or more of these conditions go false Then module operation follows the function control bits described in Figure 5 1 The module indicates it has reset its count to zero by setting the home bit bit 17 in the input status word It resets this bit when the home latch enable bit bit 07 is reset Refer to Figure 4 2 Input Status Word The system can bring the machine back to a repeatable starting position and the module count can be reset to zero by toggling either the marker input or home limit switch rather than changing bits 11 and 10 in the control word as long as the three conditions are met Carry and borrow bits are not affected by resetting the module count The home limit switch LED turns on whenev
8. 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 110 010 Counter Mode Only mE Bits 03 05 Bit 13 Up Down AC PR 2 Comparison 1 Count Up AC PR 42 Parameters for 0 Count Down AC PR 42 Preset 2 1 True Bit 12 Enable Outputs Quen 00 0 False 1 Enable 1 Enable 0 Disable 0 Disable 15952 Bits 14 17 of this word are word select bits These bits must have the setting shown in Figure 5 1 to identify the word as the output control word Bit 13 of this word is the up down bit This bit is significant only when the module is used in the counter mode The state of this bit controls module function as follows 1 The module increments its accumulated count with each count received on channel A 0 The module decrements its accumulated count with each received on channel A Publication 1771 UM006B EN P June 2002 Single Transfer Programming 5 3 Note that if a device is wired to channel B for external control of count direction the up down bit must be set to 1 Count direction can be externally controlled by using a transistor switch as described chapters 2 and 3 Bit 12 is the enable outputs bit The state of this bit controls module outputs as follows 1 Outputs enabled This means that the output module can be energized based on logical operations performed by the module 0 Outputs disabled This means that the outputs of the module
9. 20 and PLC 2 30 Processors and the Mini Processor Module the I O scan and program scan because they are sequential are synchronous one program scan occurs for each I O scan This means the scan counter can simply be incremented each program scan Section titled Scan Counter PLC 2 Family Processors describes a suitable scan counter for these processors With the PLC processor however the I O scan and program scan are asynchronous this means that the scan counter must be programmed to increment based on the longer of the two scans Section titled Scan Counter PLC Processor describes a suitable scan counter for these processors With the sample program following note that the scan counter is programmed to run continuously it resets itself when the accumulated value equals the preset value and begins to count again This arrangement is normally preferred because it allows subsequent programmed changes in bits of the output control word to be sent to the module as soon as possible after the change is made Scan Counter PLC 2 Family Processors Figure 5 6 shows an example scan counter that can be used for any PLC 2 family processor This type of scan counter increments with each program scan Because the I O and program scans of these processors are synchronous each increment of this scan counter indicates that both an I O scan and a program scan have occurred Publication 1771 UM006B EN P June 2002 5 10 Single Transfer Progra
10. 2002 3 4 Installation Figure 3 2 Connection Diagram Showing Typical 1771 IK Counter Applications with External Count Direction Output 1 dc Load Ch T 1224V anne Counter Common SI US Device 622 216 Channel B 309 DI 4G Output 2 Marker lt dc Load Q5 S 12 24V Common GI 7 LIS Not Not 698 ID Assigned Assigned 629 IS Transistor e Limit NI LAN Switch Ground at Switch Qi HO I O Chassis Only Common Q 12 EN 12 24 12 24V dc Isolated Power Module External Supply Power Supply If necessary If multiple power sources are used maintain isolation between supplies Note The module must be placed in a single module group 0 1 Note Use isolated external supplies as shown here or use a single supply as shown on figure 3 1 159 Shielded Cable The cable has a foil shield with a bare drain wire The drain wire should be connected to the enclosure ground at an I O chassis mounting bolt or stud Connect the drain wire at only one end The foil and drain at the other end of the cable which connects to the device should be cut short and taped back to i
11. A WN005 0002 0 WN005 0004 500 Special Programming 7 3 Figure 7 2 Ladder Logic for Extending the Count Beyond 999 PLC 3 Program RUNG NUMBER RMO MVM MOVE WITH MASK A WB002 0200 0110000101011100 B WB005 0000 000011111111111111 R WB005 0001 0000000101011100 MOV MOVEFROMA TO R WB005 0001 0000000101011100 WN005 0000 RUNG NUMBER RM1 348 SUB A B R WN005 0000 348 WN005 0001 348 RUNG NUMBER RM2 R WN005 0002 0 WNO05 0002 emi COUNTER UP 0100 CP 32000 CA 4 WN005 0002 CTD COUNTR DOWN C0100 CP 32000 CA RUNG NUMBER RM3 MOVE FROMA TO R WN005 0000 348 WN005 0001 348 Publication 1771 UM006B EN P June 2002 7 4 Special Programming Publication 1771 UM006B EN P June 2002 Rung Descriptions Figure 7 2 Rung 0 This rung strips the upper byte of the count value and stores the value BTR status B Mask Temporary count storage with upper byte removed A Temporary count storage with upper byte removed New count value Rung 1 This rung subtracts the old count value from the new value and stores the difference with its sign A New count value B Old count value Difference of new count value less old value Rung 2 This rung looks at the sign and magnitude of the difference from rung 1 and compares it with a constant a constant less than 999 2 or 4095 2 If positive the up counter 1s incremente
12. O scan for bidirectional module processor communication The I O scan is an automatic function of the processor during which it performs two operations it writes output image table data to I O modules and reads I O module data into the input image table The write cycle of the I O scan must be manipulated by the program for communication with the encoder counter module By this manipulation up to three 16 bit words are sent to the module by using one output image table word The read cycle of the I O scan is also used but is not manipulated by the program since only a single input status word is read from the module Publication 1771 UM006B EN P June 2002 5 6 Single Transfer Programming Bidirectional single transfer programming then requires both an input image table and an output image table word The addresses of these image table words depend on the location of the I O module in the chassis For example for modules in I O rack 1 module group 6 the corresponding output image table word is 016 the input image table word is 116 Because the encoder counter module occupies one module group in the I O chassis the processor writes one complete 16 bit output image table word to the module and reads one complete 16 bit input image table word from the module during each I O scan Figure 5 4 shows the relationship of module slot placement to image table location in memory Figure 5 4 Example Module Position Image Table Word Relationship
13. These bits control module function in both encoder and counter modes They permit the counting function of the module to be enabled or reset by the program The table in Figure 6 1 shows the bit settings for each function Bits 05 17 of this word are not used by the module and may have any setting Publication 1771 UM006B EN P June 2002 6 4 Block Transfer Programming Publication 1771 UM006B EN P June 2002 Preset Words In block transfer communication preset words 1 and 2 have the format of Figure 6 2 Here bits 00 13 store the preset value When BCD operation has been selected these bits may represent a value from 000 999 When 12 bit binary operation has been selected the value may range from 0 to 1111 1111 1111 binary 4095 decimal module switch selection is made during installation to select either BCD or binary mode Figure 6 2 Preset Words Block Transfer Mode AC PR Bits 15 17 AC PR Comparison Parameters for AC PR Preset Value Preset Value 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 Most Middle Least Significant BCD Diait Significant Bit 14 BCD Digit 0 9 BCD Diait 0 90 Not used 0 9 or 12 bit binary vai Fl Module switch delection determines whether bits 00 13 are of binary or BCD format 15961 Note If BCD operation has been selected only BCD digits should be ent
14. change it as required during operation Publication 1771 UM006B EN P June 2002 6 2 Block Transfer Programming Figure 6 1 Control Word Block Transfer Mode Bit 03 Up down 1 count up 0 count down Significant in counter mode only Bits 05 17 Not used Bits 00 01 Function May have any setting Control See Table 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 Bit 02 Enable outputs 1 Enable 0 Disable Bit 04 Home Latch Enable 1 Enable 0 Disable Table Function Control Bits BIT BIT 01 00 FUNCTION 0 0 Count 0 1 Reset and hold the accumulated count at 000 Return the accumulated count to 1 0 000 and begin counting immediately Invalid module executes previously 1 1 programmed function 15960 Bit 04 is the home latch enable bit The module resets the count to zero when all three of the following conditions are true e Home latch enable bit bit 04 is set to 1 e Marker input is high e Home limit switch is closed limit switch LED is on The count remains at zero until one or more of these conditions go false Then module operation follows the function control bits described in Figure 6 1 Publication 1771 UM006B EN P June 2002 Block Transfer Programming 6 3 The module indicates it has reset its count to zero by setting the home bit bit 17 in the input status word It resets this bit when the home latch enable bit bit 04 is res
15. either BCD or binary mode Figure 5 2 Preset Word 1 Single Transfer Bits 14 17 Word Select Bits must have this pattern for Preset Word 1 Preset Value 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 0 1 0 0 Most Middle Least Significant BCD Digit Significant DO 0 9 BCD Digit 0 9 0 9 or 12 bit binary uM Module switch selection determines whether bits 00 13 are of binalry or BCD format 15953 Single Transfer Programming 5 5 Single Transfer Description Figure 5 3 Preset Word 2 Single Transfer Bits 14 17 Word Select Bits must have this pattern for Preset Word 2 Preset Value po De 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 0 0110 _ Most Middle Least Significant BCD Digit Significant BCD Digit 0 9 BCD Digit EE 0 98 S or 12 bit binary valud Module switch selection determines whether bits 00 13 are of binalry or BCD format 15954 Note that bits 14 17 have a unique coding to identify each preset word Note If BCD operation has been switch selected only BCD digits should be entered in the data table word output to the module If non BCD digits are entered in a preset value the module sets its default preset value to 000 for the word Single transfer programming uses the I
16. transfer read BTR operations Rung 3 When the processor successfully completes a BTR operation it sets the done DN bit and enables the file to file move FFM instruction The FFM instruction moves the BTR data file CCC DDD into a storage data file EEE FFF This prevents the processor from using invalid data if a block transfer communications fault should occur Figure 6 4 Example Ladder Logic for PLC 2 Block Transfer 010 BLOCK XFER WRITE CEN DATA ADDR 0050 16 MODULE ADDR 101 110 BLOCK LENGTH 0 DN FILE 0200 0277 16 010 BLOCK XFER READ EN DATA ADDR 0051 Hu MODULE ADDR 101 110 BLOCK LENGTH 0 BN FILE 0203 0302 FILE FILE MOVE 1 COUNTER ADDR 0053 17 POSITION 001 FILE LENGTH 001 0053 FILE A 0203 0203 DN FILE R 0204 0204 15 RATE PER SCAN 001 15963 For PLC 2 family processors we recommend that you set the block length to zero Then the module determines the number of transfer words The 1771 IJ IK defaults to 3 words in a BTW and 1 word in a BTR if you program a block length of zero Block Transfer Programming 6 7 PLC 3 Family Processors Use the following ladder logic with PLC 3 or PLC 3 10 processors This program assumes that your application requires a single BTR and BTW instruction to pass data between the processor and the module Ladder logic alternates the execution of BTR and BTW instructions The pr
17. 2 Figure 4 2 Input Status Word Single Transfer and Block Transfer Bit 17 home bit Set to 1 when Module Marker input high Accumulated and Count limit switch input TRUE and 17 16 15 14 13 12 11 10 07 06 05 04 03 02 01 00 Home latch enable bit is set ON in control word Most Middle Least Bit 16 carry bit Significant BCD Digit Significant BCD Diait 0 9 B D Digit Bit 15 borrow bit 0 9 0 9 Bit 14 diagnostic bit 1 module fault detected 0 normal operation as or 12 bit binary value 15951 odule switch selection dtermines whether bits 00 13 are of binary or BCD format Publication 1771 UM006B EN P June 2002 Module Processor Communication 4 3 Bits 00 13 of this word show the accumulated count kept by the module This count may be stored either in BCD form as 000 999 decimal or in 12 bit binary form as a binary value from 0000 0000 0000 to 1111 1111 1111 A switch selection set during module installation determines the numerical form in which the accumulated count is stored Bits 14 17 of this input word serve as status bits Bit 14 the diagnostic bit is set to 1 if the module has detected a fault in its own operation normally this bit is 0 Bits 15 and 16 are the carry and borrow bits respectively These bits indicate whether the count has overflowed or underflowed Bit 17 of the input status word is the home bit Three conditi
18. 956 Accumulated Value Publication 1771 UM006B EN P June 2002 5 8 Single Transfer Programming Multiplexing Publication 1771 UM006B EN P June 2002 Rung 4 shows the input status word examined in the user program Note that this word is automatically in the input image table when single transfer 15 selected The processor automatically updates this word each I O scan In summary when you are not using preset words you need only set bits of the output image table word which corresponds to the module This word then serves as the output control word However when using one or both preset words the output image table word is used for multiple purposes and intermediate storage word addresses must be used for output control and preset word storage The following sections outline methods for multiplexing the output words in such applications The processor writes a single word the output image table word to the encoder counter module each I O scan Multiplexing is a programming technique by which the processor can share this single output image table word and use it to send multiple words to the module one word at a time Multiplexing therefore is useful when one or more preset words are needed Multiplexing requires an orderly sequencing of events in the program The program must coordinate control of the output image table word such Multiplexing requires an orderly sequencing of events in the program The program must coordina
19. C 60068 2 2 Test Bd Operating Dry Heat IEC 60068 2 14 Test Nb Operating Thermal Shock 32 to 140 F 0 to 60 C IEC 60068 2 1 Test Ab Unpackaged Nonoperating Cold IEC 60068 2 2 Test Bb Unpackaged Nonoperating Dry Heat IEC 60068 2 14 Test Na Unpackaged Nonoperating Thermal Shock 40 to 185 F 40 to 85 C IEC 60068 2 30 Test Db Unpackaged Nonoperating Damp Heat 5 to 95 noncondensing IEC 60068 2 27 Test Ea Unpackaged Shock 30g 50g IEC 60068 2 6 Test Fc Operating 2g 10 500Hz IEC 61000 4 2 4kV contact discharges IEC 61000 4 3 10V m with 1kHz sine wave 8096 AM from 30MHz to 1000MHz 10V m with 200Hz 5096 Pulse 10096 AM at 900MHz IEC 61000 4 4 1kV 5kHz on signal ports IEC 61000 4 5 2KV line earth CM on shielded ports IEC 61000 4 6 10V rms with 1kHz sine wave 8096 AM from 150kHz to 30MHz CISPR 11 Group 1 Class A with appropriate enclosure None open style Belden 8761 for pulse counter applications below 20KHz Belden 9182 for frequencies up to 50KHz CORRA 8725 for twisted pair encoder applications below 20KHz 2 Sensor must be within 40ft of the module Cat No 1771 WB 7 9 pound inches 0 6 0 7Nm Specifications A 3 Specifications 1771 1 and IK Encoder Counter Modules Field Wiring Arm Wiring Size 14 22AWG 2 5 0 25mm solid or stranded copper wire rated at 609C or greater Insulation 3 64 inch 1 2mm maximum Category Certifications UL UL Listed In
20. ER Data File N10 15 Length 0 Continuous N File 2 Rung 1 10 10 N11 10 BTR 1 E 1 t BLOCK TRNSFR READ EN 15 15 Rack 0 Group 0 DN Module 0 Control Block 1 10 ER Data File N11 15 Length 0 Continuous N 15965 Rung Descriptions Rungs 0 and 1 Rungs 0 and 1 execute BTW and BTR instructions alternately When the processor completes the BTW instruction it enables the BTR instruction immediately in the same scan Enabling a block transfer instruction places the block transfer request in queue There is one queue for each I O chassis Waiting time depends on the number of queued requests ahead of it Publication 1771 UM006B EN P June 2002 Extending the Count Beyond 999 Chapter 7 Special Programming The input Status word stores a maximum count of 999 BCD If using binary resolution the maximum count is 1111 1111 1111 4095 binary To count beyond these full scale values you may want to use either of the following ladder programs for PLC 2 or 3 family processors Both programs Figure 7 1 and Figure 7 2 extend the count beyond 999 4095 binary in the same manner Either program compares the new count value with the value in the previous scan old value If the difference of the new value less the old value is greater than a constant a constant less than 999 2 or 4095 2 the count passed through zero If the sign of the difference is negative the up counter is incremented by on
21. The module can also return the accumulated count to the processor for arithmetic computations or display The module also provides inputs for a marker signal from an encoder and a voltage level signal from a limit switch to allow for home positioning In the count mode the direction of the count can be changed either from the processor or for speed critical application at the module itself through an external switch The maximum detectable input pulse frequency of the module is 50kHz Publication 1771 UM006B EN P June 2002 1 2 Introduction Publication 1771 UM006B EN P June 2002 Figure 1 1 Encoder Counter Module cat no 1771 IJ IK Slotted for I O Insertion Only Brown Identification Label Status indicators Protective Cover Label Identifies User Output Connections Field Wiring Arm Connects Here 15942 The module will count in either BCD or binary numbers In the BCD mode the range is 000 to 999 with carry and borrow bits provided to cascade counters in the program The binary mode allows a higher count total with a range of 0000 to 409510 but the number appears at the processor in binary Additionally the module can improve the accuracy of certain quadrature type of encoders by adding the count at both channel A and channel B times 2 mode or by counting the rising and falling of both channel inputs to give a fourfold increase in the count times 4 mode The encoder counter module is available in tw
22. ble word 18 readily apparent it must be used to serve multiple purposes not only will this word send the output control word it is also needed to send one or both preset words to the module The use of this word for more than one purpose is termed multiplexing For multiplexing program manipulation and coordination of the control of the output image table word are necessary Sections titled Multiplexing and Example Program Single Transfer describe multiplexing for single transfer communication Example Rungs No Preset Words Used Figure 5 5 illustrates a typical example in which bidirectional single transfer occurs assuming that no preset words are used This example assumes the module placement shown in Figure 5 4 There is no manipulation of intermediate storage words when only the output control word is needed Thus in this instance the bits in the output image table word corresponding to the module are set directly to determine the module s control function In the example of Figure 5 5 rungs 1 3 turn on various bits in the output word Bits are 0 unless set to 1 by a program instruction Here it is assumed that no other use 15 made of word 016 Figure 5 5 Example Rungs Single Transfer No Preset Words used Rung No 01617 1 H Set Control Word Bits as 01613 pap Word 2 16 Used e Directly For Control Word 01607 Function i 201600 020 4 0414 000 056 Examine Input Status Word 15
23. ch or gate should be used to pull the channel B input low The gate or switch must sink 14ma of current to pull the channel B input low The count changes direction in less than 0 01ms from the time channel B input changes state The 1771 IK module is designed to accept several types of devices that will operate the 12 to 24V dc range Figure 2 2 Since most high voltage quadrature encoder outputs produce signals through an open collector output the module is configured for a pull up on channel B Channel A must be set for a pull up by setting switch 1 on and switch 2 off Some counting devices may also use a pull up arrangement Figure 2 2 Input Configuration for Channel A of the 1771 IK Showing Functions of Switch Assembly SW 2 Module Switch Assembly SW2 External Voltage Switch 1 Pull up Switch 2 Pull down fal O Switch 3 Filter Switch 1 Channel A O Q Switch 2 Common Sensing Circuits Y 10 27 Switch 3 O The settings on the input configuration switch assembly SW 2 are not the same on the 1771 IJ as they are for 1771 IK Refer to Table 2 D for switch settings Publication 1771 UM006B EN P June 2002 15946 2 6 Preliminary Adjustments Publication 1771 UM006B EN P June 2002 Table 2 D Input Configuration Switch Assembly 1771 IK SW 2 On Filter in 50 Hz or it oo GOK Certain counting devices may need an input designed to pull current d
24. d by one if negative the down counter is decremented by one Rung 3 This rung moves the new count value to the old count storage location R A New count value R Old value storage location Appendix A Specifications Specifications 1771 1 and IK Encoder Counter Modules General Input Specifications Number of Counters Counter Input switch selectable Input Pulse Rate Data Transfer Modes switch selectable 1771 1 External supply Input Ratings Output Ratings Power Dissipation Thermal Dissipation 1771 IK External Supply Vext Input Ratings Output Ratings Power Dissipation Thermal Dissipation General Specifications Module Location 1 0 Isolation Limit Switch Input Backplane Power Supply 5V Current Requirements Current consumption from external power supply Single channel counter Dual channel encoder 50KHz maximum Single transfer mode Block transfer mode 5 de 0 25V Vin 0 5V de Vih min 2 4V de Vil max 0 6V de Device driving input terminal must be able to sink 16A minimum 2 open collector outputs without internal pull up resistors lout 500mA maximum per output Vout 5V dc maximum 1771 lJ 6 7 Watts maximum 1771 lJ 22 9 BTU hr 12 24V dc Input circuits require 170mA maximum Output circuits require 1 08A maximum 0 Vin Vext Vext 12V dc Vih 7 2V dc max Vil 4 8V dc max Device driving input terminal must si
25. dered as logic 0 or false Table 2 C Input Configuration Switch Assembly 1771 10 SW 2 _ Chen nA Single ended Single ended Single ended of Diferential The marker input registers as true when the input pulse from the encoder is high The limit switch input senses a voltage of greater than 10 volts dc as logic 1 on and less than 5 volts dc as logic 0 off The input voltage that appears through the switch should be from a 12 to 48V dc external supply capable of supplying 10mA of source current at 48V dc The limit switch input has a signal delay of 16ms 7ms because of the filtering needed to protect against contact bounce The channel B input can be used in the counter mode to select count direction Ifthe channel B input terminal is not connected the control word in the output program selects the direction of the count For external hardware control the count direction bit in the control word must be set to count up Then if channel B is allowed to float high or is driven high the module counts up if it is pulled low either through a gate or a transistor switch it will count down 1771 IK Channel A Preliminary Adjustments 2 5 No special filtering is provided on channel B since the filtering necessary for a mechanical switch would defeat the purpose of a very fast count direction change that is not dependent on the processor scan time Therefore a transistor swit
26. dustrial Control Equipment when product is marked CSA CSA Certified Process Control Equipment CE European Union 89 336 EEC EMC Directive compliant with EN 61000 6 4 Industrial Emissions EN 50082 2 Industrial Immunity EN 61000 6 2 Industrial Immunity EN 61326 Meas Control Lab Industrial Requirements C Tick Australian Radiocommunications Act compliant with AS NZS 2064 Industrial Emissions 1 Usethis conductor category information for planning conductor routing Refer to publication 1770 4 1 Industrial Automation Wiring and Grounding Guidelines 2 Seethe Product Certification link at www ab com for Declarations of Conformity Certificates and other certification details Publication 1794 UM006B EN P June 2002 A 4 Specifications Publication 1794 UM006B EN P June 2002 Numbers 1771 description 1 2 1771 description 1 2 bit description output word for block transfer 6 3 single transfer 5 2 block transfer output words 6 1 preset words 6 4 block transfer programming 6 1 example 6 5 PLC 2 example 6 5 PLC 3 example 6 7 PLC 5 example 6 9 C cable selection 3 2 communication between module and processor 4 1 control word 4 2 count resolution 2 2 counter mode 2 3 D data format 2 4 description 1771 2 4 1771 IK 2 5 control word 4 2 5 2 input status word 4 2 preset words 4 2 single transfer 5 5 E encoder counter general description 1 1 encod
27. e if positive the down counter is decremented by one Publication 1771 UM006B EN P June 2002 7 2 Special Programming Figure 7 1 Ladder Logic for Extending the Count Beyond 999 PLC 2 Program SUBTRACT PREVIOUS COUNT FROM CURRENT COUNT STORE IN 0077 CURRENT PREVIOUS NEW OLD 5 COUNT COUNT COUNT DIFF 0113 0577 0077 1 GET HH GET M 125 168 043 IF THE DIFFERENCE IS GREATER THAN A CONSTANT COUNT PASSED THROUGH ZERO THEN INCREMENT THE COUNT THE CONSTANT MUST BE LESS THAN 1 2 THE TOTAL COUNTS OF THE IJ IK HALF OF 999 OR 4095 NEW OLD PASSED COUNT THROUGH CONSTANT DIFF ZERO 0072 0077 0076 2 GET lt Pr 400 043 00 AFTER PASSING THROUGH 0 IF THE SIGN OF THE DIFFERENCE IS NEGATIVE THEN INCREMENT THE COUNT IF POSITIVE THEN DECREMENT THE COUNT PASSED DIFF MOST THROUGH VALUE SIGNIF ZERO NEGATIVE DIGITS 0076 0077 0052 3 gt 00 16 Pre 999 002 PASSED DIFF MOST THROUGH VALUE SIGNIF ZERO POSITIVE DIGITS 0076 0077 0052 4 4 00 16 999 002 DISPLAY THE TOTAL COUNT AND MOVE THE CURRENT COUNT TO THE PREVIOUS COUNT MOST CURRENT PREVIOUS SIGNIF 5 DIGITS COUNT COUNT 0052 0113 0577 Publication 1771 UM006B EN P June 2002 LES lt B A WN005 0002 0 B WN005 0003 500 GRT gt
28. ed for mechanical counting filter has been put in and the counting frequency does not exceed 50Hz To use the module in the counter mode switch 4 must be set to counter off Publication 1771 UM006B EN P June 2002 2 4 Preliminary Adjustments Binary BCD Data Format 1771 1 Publication 1771 UM006B EN P June 2002 Binary BCD data format switch 5 The preset values and the accumulated total in the status word have the option of appearing in either BCD or binary formats If the BCD format is selected the processor can directly manipulate these values in comparisons or arithmetic functions but the accumulated value is limited to a count between 000 and 999 The binary option allows an increased range of 0000 to 409510 With some processors the programming must reconstruct a BCD number from the binary value To select binary mode set switch 5 on To select BCD mode set switch 5 off Because different types of input devices are compatible with different voltage ranges the 1771 IJ 5 dc and 1771 12 24V dc input channels are configured differently Because the 1771 IJ module is designed to work with 5V TTL type devices each input channel and the marker input can be set for single ended or differential line inputs Table 2 C The input device should be capable of providing 16mA of sink current The module detects a voltage of 2 4V dc or above at either channel as logic 1 or true voltage below 0 6V dc 1s consi
29. er 5 5 1 Output Words Single Transfer 5 1 Output Control Word 5 1 Preset NOUS cn TT 5 4 Single Transfer Description 5 5 Example Rungs No Preset Words Used 5 7 Muluplexint RE E ROCK seeds eu eau 5 8 Scan Counter PLC 2 Family Processors 5 9 Scan Counter PLC Processor 5 10 Example Program Single Transfer 5 12 Publication 1771 UM006B EN P June 2002 toc ii Table of Contents Block Transfer Programming Special Programming Specifications Publication 1771 UM006B EN P June 2002 Chapter 6 General due ae 6 1 Output Words Block Transfer 6 1 Output Control Word des 6 1 Preset OMS ERE 6 4 Example Block Transfer Programs 6 5 PLC 2 Family Processors 6 5 Rung Descriptions 6 6 PLC 3 Family 50 5 6 7 PLC 5 Family 5015 6 9 Chapter 7 Extending the Count Beyond 999 7 1 Rung Descriptions Figure 7 2 7 4 Appendix co 1 General General Description Chapter 1 Introduction This publicatio
30. er counter selection 2 2 example block transfer programs 6 5 single transfer no preset words 5 7 PLC 2 5 12 external power requirements 1 4 Index indicators status 1 3 input configuration switch 2 6 input status word 4 2 K keying band placement 3 4 keying the I O slot 3 4 mode counter 2 3 module placement 3 1 multiplexing orderly sequence 5 8 0 options programming 2 1 programming option switch 2 1 output word block transfer bit description 6 3 output words block transfer 6 1 placement module 3 1 power requirements 1 4 external 1 4 preset words 4 2 block transfer 6 4 single transfer 5 4 program options switch 2 1 programming block transfer 6 1 extending count 7 1 single transfer 5 1 programming options 2 1 Publication 1771 UM006B EN P June 2002 2 Index S scan counter PLC 2 5 9 selection cable 3 2 encoder counter 2 2 setting switches 2 7 single transfer bit description 5 2 output words 5 1 preset words 5 4 status indicators 1 3 switch data format 2 4 input configuration 2 6 settings 2 7 Publication 1771 UM006B EN P June 2002 Allen Bradley Publication Problem Report If you find a problem with our documentation please complete and return this form Pub Name Encoder Counter Modules User Manual Cat No 1771 14 1771 IK
31. er the home limit switch is closed Publication 1771 UM006B EN P June 2002 5 4 Publication 1771 UM006B EN P June 2002 Single Transfer Programming Bits 00 05 are significant only when one or both preset words are used These bits establish the comparison conditions for module control of its outputs As Figure 5 1 shows bits 00 02 set up parameters for comparison with preset word 1 bits 03 05 set up parameters for comparison with preset word 72 The module then controls its output 1 or 2 based on the true or false comparison of its accumulated count with these presets When any of these bits is set to 1 the indicated condition is considered by the module as true that is as a true condition enabling the module to turn on its output As Figure 5 1 shows one bit is used for each comparison parameter less than equal to or greater than Note that more than one of these bits can be set to 1 for each preset allowing such combinations as less than or equal to greater than or equal to or not equal to Preset Words In single transfer communication the preset words have the format of Figure 5 2 and Figure 5 3 In this format bits 00 13 store the preset value When BCD operation has been selected these bits may represent a 3 digit value from 000 999 When 12 bit binary operation has been selected the value may range from 0 to 1111 1111 1111 binary 4095 decimal A module switch selection made during installation selects
32. ered in the data table word output to the module If non BCD digits are entered in a preset value the module sets its default preset value to 000 for that word Bits 15 17 establish the comparison to be made by the module between its accumulated count and each preset value When any of these bits are set to 1 the module makes the indicated comparison between its accumulated count and the appropriate preset word value When the comparison is true the corresponding output of the module may be energized Of course the enable outputs bit in the control word must also be set to 1 for outputs to be energized As Figure 6 2 shows one bit is used for each comparison parameter less than equal to or greater than Note that more than one of these bits can be set to 1 for each preset allowing such combinations as less than or equal to greater than or equal to or not equal to Bit 14 of each preset word is not used It may be 1 or 0 Example Block Transfer Programs Block Transfer Programming 6 5 Note that there 1 no identifying bit pattern to distinguish preset words 1 and 2 from each other The encoder counter module identifies these words by their order of transmission in block transfer As these words are stored in memory preset word 1 1 stored in the word immediately following the output control word Preset word 2 is then stored in the word immediately following preset word 1 The module communicates with any Allen Bradley p
33. et Refer to Figure 4 2 Input Status Word The system can bring the machine back to a repeatable starting position and the module count can be reset to zero by toggling either the market input or home limit switch rather than changing bits 01 and 00 in the control word as long as the three conditions are met Carry and borrow bits are not affected by resetting the module count The home limit switch LED turns on whenever the home limit switch is closed Bit 03 of this word 1s the up down bit This bit is significant only when the module is used in the counter mode The state of this bit control module function as follows 1 The module increments its accumulated count with each pulse received on Channel A 0 The module decrements its accumulated count with each pulse received on channel A Note that if a device is wired to the Channel B input of the module for external count direction the up down bit must be set to 1 Bit 02 is the enable outputs bit The status of this bit controls module outputs as follows 1 Outputs enabled This means that the outputs of the module can be energized based on logical operations performed by the module 0 Outputs disabled This means that the outputs of the module cannot be energized With bit 02 set to 1 the module can energize its output terminals based on a comparison of its accumulated count and preset values entered by the program Bits 00 and 01 are termed function control bits
34. f all output devices if they are to be driven directly from the module must be added to the requirements of the module It is also possible to drive output devices from a separate load supply using the output on the module only as a switch When the output is on and conducting a maximum of 0 5V dc 1 dropped across it The load supply voltage should not exceed 30V dc Refer to Figure 1 3 for the necessary modifications to the wiring diagram Output Transistor Figure 1 3 Modification of Output Circuit for Application of Separate Load Power Supply Module Load External Power Supply Supply Right Swing Arm External Load Module 11 Module e Output Return e 20r4 12 Common e e Publication 1771 UM006B EN P June 2002 If multiple sources are used maintain isolation between supplies The power for the input device can be provided by the module s external power supply but unlike the power for the output device this is not available through the module Ifa high degree of isolation is needed use a separate input power supply If a limit switch is used the limit switch input 15 configured to accept voltage of 12 to 48V dc requiring a maximum of 10mA at 48V dc General Block Transfer Single Transfer Chapter 2 Preliminary Adjustments The module has programming options Table 2 A that are selected by setting the five switches
35. h the encoder counter module when more than one word must be output to the module that is when one or both preset words are used By using block transfer in these applications you can avoid any involvement with multiplexing techniques for module processor communication Multiplexing techniques are used in single transfer programming as described in chapter 5 Note however that single transfer techniques can be the easiest to use in any application where only a single output control word must be sent to the module For this reason when not using any of the preset words use single transfer programming for module processor communication The material for block transfer is organized as follows e Section titled Output Words Block Transfer describes the configuration of output words when using block transfer e Section titled Example Block Transfer Programs describes block transfer ladder logic for PLC 2 PLC 3 and PLC 5 family processors The output control and preset words have a unique configuration when block transfer programming has been selected Initially the program must set the bit combinations of these words to the proper arrangement for the application Then through block transfer these words are transmitted to the encoder counter module Output Control Word Figure 6 1 shows the configuration of the output control word for block transfer By setting bits in this word you set up the initial mode of module operation and
36. he module Use Belden 8761 cable for pulse counter applications with a signal below 20K Hz use Belden 9182 cable for frequencies up to 50k Hz Use Belden 8725 cabe 4 twisted pair cable for encoder applications below 20k Hz Installation 3 3 Figure 3 1 Connection Diagram Showing Typical 1771 Encoder Application Output 1 TTL Load Output Channel A TIL anne Di TO Output Common Output Encoder ve NE 2 09 Return Channel B amp Common Output 2 a Marker SE uo TTL Load Os S Out put Common Gs JS Device S L Not At I O Rack Not Sr O oe Chassis Assigned Qs N 10 or 11 Q Swich Sal 149 t 5V dc Module Input Device Power External Power Supply Note Use a single external supply as shown here or use an additional isolated supply as shown on figure 3 2 Note The module must be placed in a single module group 0 1 x sl n 15948 If multiple power sources are used maintain isolation between supplies If you use the limit switch you must use shielded cable such as Belden 8761 or 9182 for cabling Publication 1771 UM006B EN P June
37. ion 1771 UM006B EN P June 2002 ATTENTION Preventing Electrostatic Discharge This equipment is sensitive to electrostatic discharge which can cause internal damage and affect normal operation Follow these guidelines when you handle this equipment Touch a grounded object to discharge potential static e Wear an approved grounding wriststrap Do not touch connectors or pins on component boards e Do not touch circuit components inside the equipment e Ifavailable use a static safe workstation e When not in use keep modules in appropriate static safe packaging The module may be placed in 1771 I O chassis However the module must only be inserted in a single module group it cannot straddle two groups To minimize noise group low voltage input modules together within a single I O chassis whenever possible Remove power from the I O chassis backplane and wiring arm before removing or installing a module e Failure to remove power from the backplane could cause unexpected machine operation with possible damage to equipment or injury to personnel It could also damage the module or degrade performance e Failure to remove power from the wiring arm could damage the module or degrade performance Use the proper cable to connect the input devices to the module field wiring arm Follow the appropriate connection diagram Figure 3 1 and Figure 3 2 Input devices cannot be more than 40 cable feet from t
38. irements associated with any particular installation Rockwell Automation does not assume responsibility or liability to include intellectual property liability for actual use based upon the examples shown in this publication Allen Bradley publication SGI 1 1 Safety Guidelines for Application Installation and Maintenance of Solid State Control available from your local Rockwell Automation office describes some important differences between solid state equipment and electromechanical devices that should be taken into consideration when applying products such as those described in this publication Reproduction of the contents of this copyrighted publication in whole or part without written permission of Rockwell Automation is prohibited Throughout this publication notes may be used to make you aware of safety considerations The following annotations and their accompanying statements help you to identify a potential hazard avold a potential hazard and recognize the consequences of a potential hazard Identifies information about practices or circumstances that can cause an explosion in a hazardous environment which may lead to personal injury or death property damage or economic loss Identifies information about practices or circumstances that may lead to personal injury or death property damage or economic loss Identifies information that 1s critical for successful application and under
39. may be potential difficulties ensuring electromagnetic compatibility in other environments due to conducted as well as radiated disturbance This equipment is supplied as type equipment It must be mounted within an enclosure that is suitably designed for those specific environmental conditions that will be present and appropriately designed to prevent personal injury resulting from accessibility to live parts The interior of the enclosure must be accessible only by the use of a tool Subsequent sections of this publication may contain additional information regarding specific enclosure type ratings that are required to comply with certain product safety certifications See NEMA Standards publication 250 and IEC publication 60529 as applicable for explanations of the degrees of protection provided by different types of enclosures Also see the appropriate sections in this publication as well as the Allen Bradley publication 1770 4 1 Industrial Automation Wiring and Grounding Guidelines for additional installation requirements pertaining to this equipment The 1771 IJ and 1771 IK are modular components of the 1771 I O system and require a properly installed system chassis Refer to publication 1771 075 for detailed information on acceptable chassis and proper installation and grounding requirements Publication 1771 UM006B EN P June 2002 3 2 Installation Module Placement Recommended Cable Publicat
40. mming Rung No Figure 5 6 Scan Counter PLC 2 Processors 030 CTU PR003 AC000 030 CTU PR003 AC000 Branch End Instruction 15957 11111 200 1 1 The output instruction of both rungs in Figure 5 6 15 an up counter CTU instruction The first rung since it is unconditional is always true The second rung since a branch end instruction by itself is always false sets the conditions for the counter as false Because an up counter CTU increments for each false to true transition CTU 030 registers one count each time the program scan occurs Scan Counter PLC Processor Figure 5 7 shows an example scan counter that can be used for a PLC processor Because the I O and program scans of this processor are asynchronous this scan counter differs in form and operation from the scan counter for PLC 2 processors Figure 5 7 Scan Counter PLC Processor 20017 11111 CTU J PR006 AC000 1 20017 Publication 1771 UM006B EN P June 2002 1 15958 Single Transfer Programming 5 11 In order to keep track of both I O and program scans the PLC scan counter rungs manipulate a particular type of memory bit This must be a bit in the input image table which is not wired to a corresponding input device so that the bit is turned off each I O scan Choose a bit which satisfies all of the following conditions e isin a module group that 1s scanned immediately after the encoder cou
41. n describes installation adjustments and the programming necessary for communication between the Encoder Counter Module cat no 1771 IJ IK and a programmable controller processor The programming techniques given here enable the processor to direct the operation of the encoder counter module and to monitor its status The encoder counter module can be used with any Allen Bradley processor that uses the 1771 I O structure Depending on the intended use of the encoder counter module two different programming methods can be used These methods are e Single transfer programming Use single transfer only if the module is in a local I O chassis and generally when not using preset words If using preset words with single transfer you must use multiplexing as described in section titled Multiplexing in Chapter 5 If using single transfer disregard chapter 6 on block transfer Block transfer programming Use block transfer any time If using block transfer disregard chapter 5 on single transfer The encoder counter module maintains a count independent of the processor of input pulses that typically originate from such devices as quadrature type encoders high speed optical beam counters and certain types of switches The module Figure 1 1 is capable of making decisions based on the count total by comparing it to previously programmed values and activating either one or both of Its outputs based on the results of the comparison
42. nk or source if selected on Channel A 10mA For Vext 24V dc Vih 14 4V dc max Vil 9 6V dc max Device driving input terminal must sink or source if selected on Channel A 20mA 2 open collector outputs without internal pull up resistors lout 500mA max per output Vout Vext 1771 IK 12 1 Watts maximum 1771 IK 41 3 BTU hr Cat No 1771 I O chassis Tested to 1500V ac for 1s 12 48V dc 1 2A typical 1 4 maximum 150mA 9 12V dc 75mA 24V dc Publication 1794 UM006B EN P June 2002 Specifications Specifications 1771 1 and IK Encoder Counter Modules Indicators Keying 1771 lJ 1771 IK Environmental Conditions Operational Temperature Storage Temperature Relative Humidity Shock Operating Nonoperating Vibration ESD Immunity Radiated RF Immunity EFT B Immunity Surge Transient Immunity Conducted RF Immunity Emissions Enclosure Type Input Conductors Wire Category Length max Field Wiring Arm Field Wiring Arm Screw Torque Publication 1794 UM006B EN P June 2002 2 Channel A and B status 1 Marker 1 Limit 2 Output 1 and 2 1 Red Fault Left connector Between 6 and 8 18 and 20 Right connector Between 4 and 6 32 and 34 Left connector Between 6 and 8 20 and 22 Right connector Between 4 and 6 32 and 34 Note Modules must be in a single module group slots 0 and 1 Do not straddle 2 module groups IEC 60068 2 1 Test Ad Operating Cold IE
43. no preset words are required e Section titled Multiplexing shows how multiple words of output data are multiplexed in single transfer e Section titled Example Program Single Transfer gives a sample program for single transfer programming The output control and preset words have a unique configuration when single transfer programming has been selected Initially the program must set the bits in these words to the desired combination for the application Then using single transfer techniques the program sends these output words to the module Output Control Word Figure 5 1 shows the configuration of the output control word for single transfer By setting bits in this word you set up the initial mode of module operation and change it as required during operation Publication 1771 UM006B EN P June 2002 5 2 Single Transfer Programming Figure 5 1 Control Word Single Transfer Function Control Bits BIT BIT 11 10 FUNCTION 0 0 Count 0 1 Reset and hold the accumulated count at 000 1 0 Return the accumulated count to 000 and begin counting immediately 1 1 Invalid module executes previously programmed function Bits 10 11 Function Control see table Bits 14 17 Word Select Bits Bits 00 02 Must have this pattern for control gt 1 Comparison it word Not Used PR 1 Parameters for AC PR 1 Preset Y 1 True m alla 0 False 17
44. nsulate it from any electrical contact Publication 1771 UM006B EN P June 2002 Keying Specifications Installation 3 5 Plastic keying bands provide an easy method for keying an I O slot to accept only one type of module Use of keying bands is strongly recommended to prevent accidental insertion of the wrong type of module The module is slotted in two places on its rear edge The position of the keying bands on the backplane connector must correspond to these slots to allow insertion of the module Because the module uses two slots both slots have to be keyed Snap the keying bands on the upper backplane connectors between these numbers printed on the backplane Table 3 A Keying is different for the 1771 IJ and the 1771 IK Table 3 A Module Keying Module Right Connector 1771 1 6and8 4 and 6 18 and 20 32 and 34 1771 IK 6and8 4 and 6 20 and 22 32 and 34 Insert the module in a single module group slots 1 It must not straddle two module groups The position of the these keying bands may be changed if subsequent system design and rewiring makes insertion of a different type of module necessary Complete specifications for the 1771 IJ and IK modules are contained in Appendix A Publication 1771 UM006B EN P June 2002 3 6 Installation Publication 1771 UM006B EN P June 2002 General Optional Chapter 4 Module Processor Communication Communication between the
45. nt Resolution Encoder Counter Selection Publication 1771 UM006B EN P June 2002 Count resolution switches 2 and 3 In the encoder mode the accuracy of a quadrature type encoder can be improved by allowing the module to count the pulse trains at both channel inputs This doubles the number of pulses counted for the same degree of rotation at the encoder A further improvement can be made by letting the module count the leading and trailing edges of both pulse trains thereby counting four times times 4 for the same degree of rotation Certain applications may need the actual count and module should be set for times 1 the pulse is counted on its rising edge as high true The count resolution setting affects the total count kept at the module and as it is sent back in the status word Programming manipulations of the status word and the preset values must account for the multipliers The count resolution setting may also be limited by the program scan time if the carry or borrow bits are used to cascade counters Note In the counter mode the count resolution setting Table 2 B has no effect on the count Table 2 B Count Resolution Settings Multiplier Switch 3 Times 1 On Times 2 Off Times 4 Off Encoder counter selection switch 4 In the encoder mode the module counts the number of input pulses entering on channel A from a quadrature type encoder By comparing the phase relationship between input pulses on channel A and
46. nter module is scanned isan actual terminal address on an installed input module e is off at all times The first condition requires a brief knowledge of I O scan sequencing The remote I O PLC processor scans I O modules in order of module group no It first scans module group 0 in all I O racks then module group 1 then 2 and so on Therefore when selecting an input image table bit for scan counter control choose a bit with a greater module group no than the module group no of the encoder counter module If the encoder counter module is placed in module group 7 and unused input in module group 0 would be appropriate for this purpose Note that the I O rack number is of no consequence in selecting this bit The second condition requires that this input address correspond to an actual input module terminal of the controller For the third condition it is suggested that the input terminal at the address be connected to the L2 AC low or DC COMMON terminal on the input module wiring arm This helps prevent the terminal from being connected to an input device at some later time In Figure 5 7 it is assumed that bit 11111 satisfies all three of these conditions The I O scan and program scan both manipulate bit 11111 In rung 1 this bit is examined as an input condition for the scan counter When this bit is OFF CTU 200 increments When CTU 200 increments bit 20017 is set on In rung 2 bit 20017 latches bit 11111 on Then in r
47. o versions e cat 1771 IJ uses a SV dc external power supply that allows inputs to be TTL compatible Outputs can either be driven from the 5V dc supply through the module or from a separate load supply of a different voltage e cat no 1771 IK uses a 12 24V dc external power supply Input devices should be compatible with the voltage of the external power supply Outputs can be driven either from the external supply through the module or from a separate load supply Status Indicators Introduction 1 3 The encoder counter module is shipped with two 12 terminal gold plated Field Wiring Arms cat no 1771 WB Unless otherwise noted this manual refers to both versions of the module There are seven status indicators Figure 1 2 on the front of the left half of the module The four indicators corresponding to channel A channel B marker and switch inputs illuminate when their respective input signals are high The next two indicators show the state of the outputs An output indicator is on when the output circuit is activated The bottom indicator illuminates when the module detects a fault Figure 1 2 Red LED Status Indicators 3 CIC Channel gt c VT Channel B O Marker well Limit O O Output 1 e Outp
48. ocessor checks data validity before accepting read data and sets one enable bit at a time Refer to Figure 6 5 for generalized ladder logic and to Figure 6 6 for example ladder logic with entered values Figure 6 5 Generalized Ladder Logic for PLC 3 Block Transfer PLC 3 XOR Power A BTW E BTW cnil BTW A BTW BTR cnil XOR A BTR cnil BTR cnil 15045 Publication 1771 UM006B EN P June 2002 6 8 Block Transfer Programming WB001 0020 WB001 0030 BTR CNTL 3 BLOCK XFER READ LE RACK 002 12 Publication 1771 UM006B EN P June 2002 Figure 6 6 Sample Ladder Logic for PLC 3 Block Transfer RUNG NUMBER RM1 XOR AXORB R A WB001 0020 B WB001 0020 R WB001 0020 XOR AXORB R A WB001 0030 B WB001 0030 R WB001 0030 RUNG NUMBER RM2 BTW BLOCK XFER WRITE RACK 002 GROUP 1 MODULE 1 HIGH DATA FB002 0150 LENGTH 0 CNTL FB001 0030 EQU A B A WB001 0030 B WB001 0020 RUNG NUMBER RM3 GROUP 1 CNTL MODULE 1 HIGH DATA FB002 0220 15 LENGTH 0 CNTL CNTL FB001 0020 ER 13 15064 Rung Descriptions Rung 1 Rung one is true only at power up It uses status word 3 bit 03 the PLC 3 s AC power loss bit to zero the control file of both the BTR and BTW instructions Rung 2 The equal instruction is used at power up At power u
49. on the programming option switch assembly SW 1 These options include the choices between encoder and counter operation block transfer or single transfer BCD or binary data formats and count resolution in the encoder mode Table 2 A Programming Option Switch Assembly SW 1 5 Single See Table 2 B Encoder On Transfer Multiplier for Mode Binary Count Resolution Off Block Counter Transfer Mode BCD Block transfer single transfer switch 1 Use single transfer programming only when the module is in a local I O chassis This type of programming shifts a single word of data each program scan from the processor s data table to the module It therefore takes three program scans to send a new control word and the two preset values to the module However once new data has been sent to the module it will remain active until another transfer updates it The input status word will always appear at the proper address location in the input image table To use single transfer programming switch 1 must be set to single transfer on Block transfer moves all three data words from the processor to the module in a single scan Since the module has bidirectional block transfer the processor must also be programmed to read for block transfer or the data table will not display the status word To use block transfer switch 1 must be set for block transfer off Publication 1771 UM006B EN P June 2002 2 2 Preliminary Adjustments Cou
50. ons are required to set this bit to 1 e Marker input is high e Limit switch input is true high Home latch enable bit is on 1 The marker and limit switch input devices connect to module input terminals The home latch enable bit is in the control word one of the three output words Note that the home bit once set to 1 remains 1 until the home latch enable bit 15 reset to 0 Publication 1771 UM006B EN P June 2002 4 4 Module Processor Communication Publication 1771 UM006B EN P June 2002 General Output Words Single Transfer Chapter 5 Single Transfer Programming Single transfer programming is one method for coordinating and controlling bidirectional module processor communication This method can only be used when the module is in a local I O chassis Single transfer may be the recommended method even where block transfer capability 1 available Specifically single transfer programming is suggested whenever preset 1 words and 2 are not used When one or both preset words are used block transfer methods may be more efficient depending on the application The material for single transfer programming is organized as follows e Section titled Output Words Single Transfer describes the configuration of output words when using single transfer methods e Section titled Single Transfer Description gives a general description of how single transfer programming works and an example for applications where
51. own through the device Switch 2 should be set on for pull down and switch 1 left off The module detects a minimum of 7 2V dc at its input channels as true for a 12V dc external supply and 14 4V dc at 24V dc external supply A signal with a maximum voltage of 4 8V dc is considered false for a 12V dc supply and 9 6V dc is false for a 24V dc supply Each input channel sinks 10mA at 12V dc and 20 at 24V dc If it is necessary to debounce a contact type of device such as a switch the filter can be added across the inputs by setting switch 3 on By adding the filter to the circuit the maximum counting frequency the module will detect is 50Hz Channel B input and the marker input are for open collector encoder drivers the channel B input has an internal pull up and are not switch selectable The marker input reads a signal as high true The limit switch input senses a voltage of greater than 10 volts dc as a logic 1 on and less than 5 volts dc as a logic 0 off The input voltage that appears through the switch should be from a 12 to 48V dc external supply that is capable of supplying 10mA of source current at 48V dc The limit switch input has a signal delay of 16 ms 7ms because of the filtering needed to protect against contact bounce The channel B input can be used in the counter mode to select count direction If the channel B input terminal is not connected the control word in the output program selects the direc
52. p the BTR and BTW control files both equal zero so the BTW instruction is enabled Rung 2 and 3 During normal program execution the BTW and BTR instructions are alternately executed The done bit of either instruction enables the next block transfer instruction After power up the BTR and BTW done bits are used to alternate reads and writes Block Transfer Programming 6 9 PLC 5 Family Processors You can use the following ladder logic with PLC 5 processors This program assumes that your application requires a single BTR and BTW to pass data between the processor and the module Ladder logic alternates the execution of BTR and BTW instructions The processor checks data validity before accepting read data and sets one enable bit at a time Refer to Figure 6 7 for generalized ladder logic and to Figure 6 8 for example ladder logic with entered values Figure 6 7 Generalized Ladder Logic for PLC 5 Block Transfer BTW BTR BTW t t Control Block EN Data File yyy Continuous no BIW BTR BTR I E 3 4 t EN EN Control Block 222 Data File aaa Continuous no 15047 Publication 1771 UM006B EN P June 2002 6 10 Block Transfer Programming Figure 6 8 Example Ladder Logic for PLC 5 Block Transfer File 2 Rung 0 N10 10 N11 10 BTW ES BLOCK TRNSFR WRITE EN 15 15 Rack 0 Group DN Module 0 Control Block N10 10
53. processor and the encoder counter module is bidirectional This means that information is transferred to and from the module the processor instructs the module to perform specific functions and may provide values to be compared on the module and used for output control the module transmits its accumulated count and other status information to the processor Because both input and output data are transmitted between this module and the processor special programming techniques are used to coordinate and control this bidirectional data transfer Complete 16 bit words are transferred between the module and the processor The processor sends up to 3 words of data to the encoder counter module Control word Preset word 1 Preset word 2 These are termed the output words since they are output with respect to the program The encoder counter module sends a status word to the processor Figure 4 1 shows the transfer of output and input words in bidirectional module processor communication described in the following paragraphs Figure 4 1 Bidirectional Module Processor Communication feed EE Control Word Output Words Preset Word 1 Preset Word 2 Input Words Status Word Encoder Counter Module Cat No 1771 IJ IK 15950 Publication 1771 UM006B EN P June 2002 4 2 Module Processor Communication Outputs Words The program controls encoder counter module operation through the outpu
54. pulses appearing at channel B it knows whether to add or subtract the incoming count from the total that is whether to count up or down The phasing Figure 2 1 between the channels is determined by the direction in which the encoder is turned To use the module in the encoder mode switch 4 must be set to encoder on Encoder Encoder Preliminary Adjustments 2 3 Figure 2 1 Input Pulses Time Er ra En rr br ra Jr rr dui 3 s LLL Bb bl bi bl bi bi bi bl he ulse s ili 7 fi to Counter Channel B 111 ply tale dala te tata Pala _ db Down ILL LT Eb n LIH bl bl bi Pulsed yo Wb gb Ib lll ii ilb to Counter LULU LL x4 15945 In the counter mode the module adds the incoming pulses on channel A The count is incremented on the rising edge of the pulse high true The direction of the count can be controlled with either the control word or an external switch wired to channel B Channel B must be left unconnected if the count direction is to be software controlled Typical input device counting might be high speed static switches and incremental encoders Mechanical switches are not recommended as input counting devices used with the 1771 IJ because the contact bounces might be counted as pulses However the 1771 IK can be used with a mechanical switch provided the module is configur
55. rocessor that has block transfer capability The module is a bidirectional block transfer module Bidirectional means that the module performs both read and write block transfer operations You transfer data from your module to the processor s data table with a block transfer read BTR instruction You transfer data to your module from the processor s data table with a block transfer write BTW instruction PLC 2 Family Processors The following examples use block transfer instructions to perform block transfers However the Mini PLC 2 cat no 1772 LN3 and PLC 2 20 cat no 1772 LP1 LP2 processors use multiple GET instructions to perform block transfers Refer to the processor user s manual for an explanation of multiple GET block transfer The generalized and example programs Figure 6 3 and Figure 6 4 demonstrate the use of a single block transfer read BTR and a single block transfer write BTW to pass data between the processor and the module Figure 6 3 Generalized Ladder Logic for PLC 2 Block Transfer BTW EN File AAA BBB py BTR EN File CCC DDD DN BTR REM DN 1 File CCC DDD 2 File EEE FFF DN source destination 15962 1 2 Publication 1771 UM006B EN P June 2002 6 6 Block Transfer Programming Publication 1771 UM006B EN P June 2002 Rung Descriptions Rungs 1 and 2 These rungs request the block transfer write BTW and block
56. standing of the product Using This Manual 3 Summary This preface gave you information on how to use this manual efficiently Publication 1771 UM006B EN P June 2002 P 4 Using This Manual Publication 1771 UM006B EN P June 2002 Table of Contents Introduction Preliminary Adjustments Installation Module Processor Communication Single Transfer Programming Chapter 1 CoU cT PTT 1 1 General Description 1 1 Situs 25b EE REPE 1 3 Systemi POWE 1 44 atriale CERE E 1 4 External POWOF naines teorie ee Y 1 4 Chapter 2 General artnet 2 1 Block Transfer Single Transfer 2 1 Count Resolution 52252223 2 2 Encoder Counter Selection 2 2 Binary BOD Data Format 2 4 Ur MC EIE 2 4 PRETI mE 2 5 Setting Switch Assemblies 2 7 Chapter 3 Environment and Enclosure 3 1 Module Placement 225255552644 cena 3 2 Recommended Cable 3 2 Shielded Cable 3 4 TIE 3 5 Specifications 3 5 Chapter 4 Gala 4 1 Outputs Words 4 2 Input Status Word 4 2 Chapt
57. t words These words function as follows e Control word the control word as its name implies instructs the module on its operation and on control of its own outputs By setting specific control word bits you set up the module s initial mode of operation and can subsequently alter module operation as the application requires e Preset words 1 and 2 the optional preset words are values that can be used for comparison by the module When these words are used the module controls its own output based on comparison between its accumulated count preset values You can use these words to direct module control of its own output terminals independent of the timing of the processor I O and program scans Stored in the data table these output words are sent to the module as controlled by the program The storage and transmission of these words to the module differ depending on whether single transfer or block transfer programming is used In addition the bit by bit significance of these words is dependent on the data transfer method used For this reason specific information on the storage and composition of these words is given separately in the following chapters which describe each programming method In put Status Word The input status word is the single input word received from the encoder counter module This word has the same format for both block and single transfer programming The input status word has the format of Figure 4
58. te control of the output image table work such that it sends the intended output word whether control or preset to the module In this publication a scan counter is used for this coordination While it is not the only method of control for multiplexing the scan counter is a direct and easily understood method and can be used with any PLC or PLC 2 family processor To understand the scan counter s function consider how information must be transferred to the module In one program scan the processor stores the word that is to be sent to the module in the output image table word for the module During the very next I O scan the processor automatically outputs the image table word to the module Table 5 A lists a sequence of operation for single transfer in a typical application showing what must happen at each value of the scan counter This example assumes that both preset words are used If only one of the preset words is needed only counts 1 and 2 of the scan counter are necessary Single Transfer Programming 5 9 Table 5 A Scan Count Sequencing At Count 11 Scan Sends output word Sends output word Sends output word This count is the scan counter Accumulated value for PLC 2 PLC 2 15 PLC 2 20 and Mini PLC 2 Controllers For the PLC Controller these values would be doubled 2 4 and 6 respectively The scan counter must indicate that both an I O scan and a program scan have occurred For PLC 2 PLC 2 15 PLC 2
59. tion of the count For external hardware control the count direction bit in the control word must be set to count up Then if channel is allowed to float high or is driven high the module counts up if it is pulled low either through a gate or a transistor switch it will count down Any gate or switch should be compatible with the external voltage supply 12 to 24V dc Setting Switch Assemblies Preliminary Adjustments 2 7 No special filtering is provided on channel B since the filtering necessary for a mechanical switch would defeat the purpose of a very fast count direction change that is not dependent on the processor scan time Therefore a transistor switch or gate should be used to pull the channel B input low sinking 10mA at 12V dc or 20mA at 24V dc The count changes direction in less than 10 microseconds from the time channel B input changes state Refer to the connection diagrams Figures 3 1 and 3 2 for interfacing different devices Switch assembly settings these features are selected on two switch assemblies that are located on the circuit board underneath the component cover To select these options proceed as follows 1 Take off the left side cover by removing the four slotted screws 2 Refer to Figure 2 3 Identify the programming option switch assembly SW 1 and the input configuration switch assembly SW 2 Figure 2 4 Location of Switch Assemblies 2
60. tting the switches and understanding the operation Installation How to install the modules Module Processor Communication How the module communicates with the processor How to transfer information with single transfer programming How to transfer information with block transfer programming Special Programming Special programs to extend the count beyond 999 Specifications Module specifications We use these conventions in this manual In this manual we show Like this that there is more information about a topic in another chapter in this manual that there is more information about the topic in another manual Publication 1771 UM006B EN P June 2002 P 2 Using This Manual Important User Information Publication 1771 UM006B EN P June 2002 Because of the variety of uses for the products described in this publication those responsible for the application and use of these products must satisfy themselves that all necessary steps have been taken to assure that each application and use meets all performance and safety requirements including any applicable laws regulations codes and standards In no event will Rockwell Automation be responsible or liable for indirect or consequential damage resulting from the use or application of these products Any illustrations charts sample programs and layout examples shown in this publication are intended solely for purposes of example Since there are many variables and requ
61. ung 3 bit 20017 is turned off Bit 11111 remains on until the next I O scan With this arrangement CTU 0 cannot increment until both an I O scan and program scan occur Note that for the PLC processor two scan counts are used between each step in single transfer as indicated in NO TAG Publication 1771 UM006B EN P June 2002 5 12 Single Transfer Programming Example Program Single Transfer Note In some applications it may be feasible to designate an input location for the purpose of scan counter control In this instance an on delay timer TON instruction can be used to multiplex output data to the encoder counter module A timer with 0 1 second resolution is acceptable for this purpose Each step of Table 5 A can be programmed to be executed at a 0 1 second interval from the previous step Figure 5 8 1 an example program for single transfer multiplexing of output words to the encoder counter module This example uses the type of scan counter recommended for PLC 2 processors However the general format of these rungs would be the same for a PLC processor with addressing differences substitution of the type of scan counter shown in Figure 5 7 and other minor changes Figure 5 8 Example Program Single Transfer Rung 030 CTU 34 PR003 000 Scan Counter 030 2 CTU PR003 Branch End Instruction AC000 030 201 051 012 cup Lusi 001 030 202 052 he Output 4 eal PUT
62. ut 2 ee Fault 3 i O UIL 1 T_T 15943 When system power is turned on the module runs a self test During power up it is normal for the fault indicator to flash on momentarily If the FAULT LED does not turn off the module has detected a fault The self test includes checks to make sure that all counters and registers have been reset to zero and memory is cleared If a breakdown of communication occurs during block transfer the FAULT LED will also light Bit 14 the diagnostic bit in the input status word is also set anytime the FAULT LED is on After power up the module will stay in its reset state outputs disabled and counter held reset until the necessary control bits are set in the program Publication 1771 UM006B EN P June 2002 1 4 Introduction System Power External Power System power 1 supplied through the I O chassis backplane from the 5V dc chassis power supply The module requires a current of 1 4A The sum of the current requirements of all modules in the chassis must not exceed the power supply or backplane rating The module requires an external power supply connected to the field wiring arm For the 1771 IJ the supply must be able to deliver 140mA at 5V dc 0 25V with less than 50mV ripple peak to peak The 1771 IK requires 110mA at 12V dc or 200mA at 24V dc with less than 50mV ripple peak to peak These requirements are for the module only The current requirements o

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