1771-2.109, Loop Controller Interface Module, Product Data
Contents
1. The keying bands on the backplane connector are Between 12 and 14 Between 16 and 18 Product Data Loop Controller Interface Module Installing the Module To insert a module into the I O chassis 1 Remove power from the I O chassis 2 Open the module locking latch and insert the interface module into the slot keyed for it 3 Firmly press the module into its backplane connector 4 Secure the module in place with the module locking latch 5 Reconnect power to the I O chassis Con necting the Loop The RS 485 serial link allows the module to communicate with up to 15 Controller to the Module loop controllers Connect the two devices with twisted pair cable suitable for RS 485 wiring You make these connections at the module s swing arm terminals cat no 1771 WA The swing arm allows you to remove the module without having to remove the wiring Use twinaxial cable cat no 1770 CD for the serial link or any shielded twisted pair cable that has a minimum characteristic impedance of 60 ohms and has a maximum capacitance of 75 pF per meter Connect the module and loop controllers in a daisychain configuration as long as total cable length does not exceed 4000 ft Use the following procedure to connect the loop controller to the module 1 Strip 2 inches of the outer insulation from the cable end to be connected to the wiring arm Figure 2 2 Remove the exposed foil 3 Strip approximately 3 8 inch of insula2. Figure 16 Figure 16 Error Record Format Word 1 0 0 8 0 2 COMMAND CODE ERROR CODE 3 0 0 LOOP CONTROLLER ADDRESS Error Code 01 Invalid loop controller address specified in the command 02 Address of the responding loop controller does not match the address requested by the interface module 03 Loop controller did not respond with a valid return code within three tries 04 Improper checksum was detected during a download operation 05 Improper BCD character in a data field 06 A modify parameters value is out of range 07 Module cannot execute a modify parameters a download or a set control command when the loop controller is in the panel mode Loop controller must be in the workstation mode 08 Modify parameters command requires additional data This command expects 15 words of data If some of the data is missing an error is indicated Command Code 10 Modify parameters 20 Read parameters 04 07 Upload blocks 1 through 4 0C 0F Download blocks 1 through 4 Product Data Loop Controller Interface Module Specifications Module Location Maximum Number of Loop Controllers 7711 0 Chassis 15 Operating Temperature Loop Status Update Time 0to60 C Approximately 2 sec 15 loops 32 to 140 F Communication Rate Storage Temperature 4800 baud 40 to 85 C Half duplex 40 to 185 F Backplane Power Requirement Relative Humidity Rating 5VDC 5 to 95 without condensation 1 3A Electrical Interface Key
3. Loop Controller Interface Module Loop Controller Alarm Status Word Bit Definition 0 Front Panel Change Indicator 2 A M Setting 0 manual 1 auto 1 WIP Setting 0 panel 1 workstation 3 R L Setpoint select 0 local 1 remote 4 Undefined 5 Undefined 6 Undefined 7 Alarm Indicator 1 at least one alarm is active 10 Alarm 4 H L 0 low level 2 1 high level 1 11 Alarm 4 Valid 1 alarm is active 12 Alarm 3 H L 13 Alarm 3 Valid 14 Alarm 2 H L 15 Alarm 2 Valid 16 Alarm 1 H L 17 Alarm 1 Valid Diagnostic Word Bits Definition 0 7 Controller Address 2 digit BCD 10 17 Error Code 2 digit BCD 01 Improper BCD Value 02 New Value Is Out Of Range 08 Last Loop Controller Address in the Set Control File Does Not Match the Address in Loop Status 13 Product Data Loop Controller Interface Module Modify Parameters 14 The PLC uses the modify parameters command to change the loop controller s PID parameters e alarm limits e output limits Once you use the read parameters command to examine the current loop controller parameters you can use the modify parameters command to change these parameters Important Changes you make when the loop controller is in the automatic mode affect the controller s operation as soon as it receives the command from the interface module Figure 6 khows the command s format All values are in BCD The error file reflects any detected BCD errors The
4. electrostatic discharge can damage them Handle equipment and components only in a static safe environment CAUTION If you handle components improperly the PLC Data Table Requirements You must allocate two blocks of memory within the PLC s data table for use by the interface module The module requires this memory for block transfer read and write files The maximum length of the block transfer write file is 64 words Set the length of the write file to the default value of 00 The maximum length of the block transfer read file is 64 words Set the length of the read file to 00 which allows the module to determine the proper file length You will also need to allocate portions of the data table for the files related to the module s commands Set Control Command This command enables the PLC to specify the number of loop controllers attached to the communication link e select either the auto mode or the manual mode specify either a remote or local set point s enter the value of a new set point or output e acknowledge alarms The PLC sends the command to the module via block transfer instructions The module interprets the command and sends the appropriate message out to the loop controllers over the RS 485 serial link Important The loop controller must be in the manual mode to change an output The loop controller can be in either the automatic or manual mode when changing a set point Set control setpoint output val
5. PLC 18 Product Data Loop Controller Interface Module The interface module calculates a checksum as the data transfers back to the loop controller The module then compares the download checksum to the internally calculated checksum to verify that no data was altered When the loop controller accepts the data transferred from the PLC it sends an acknowledgement as shown in figure 13 Figure 12 Download File Format Block Transfer Write Word 1 0 O 0 C 2 0 0 3 e 63 64 A Block Header 000C 000D 000E and 000F B Loop Controller Address C Beginning of Configuration Data D End of Configuration Data E Checksum Figure 13 Download Acknowledge Block Transfer Read Word 1 0 0 0 C 2 0 0 LOOP CONTROLLER ADDRESS A Block Header 000D 000E 000F and 000G B Loop Controller Address LOOP CONTROLLER ADDRESS 19 Product Data Loop Controller Interface Module Extended Loop Status 20 The PLC uses the extended loop status command to gather data from e 4 analog inputs a 2 frequency inputs e 2 Contact inputs e 2analog outputs e 2 contact outputs This command can return data from only five consecutive loop controllers at a time Figure 14 If you select more than five loop controllers the interface module processes the controllers with the five lowest addresses All values in extended loop status file are in BCD and are expressed in percent of scale The values can r
6. K Alarm 3 Level 2 99 9 to 102 0 L Alarm 4 Level 1 99 9 to 102 0 M Alarm 4 Level 2 99 9 to 102 0 N Output Upper Limit 2 0 to 102 0 0 Output Lower Limit 2 0 to 102 0 P Implied Decimal Point Product Data Loop Controller Interface Module Figure 7 Modify Parameter Command Block Transfer Read Word ff 1 0 0 1 0 A 2 0 0 LOOP CONTROLLER ADDRESS B A Block Header B Loop Controller Address Read Parameters The read parameter command enables the PLC to read the loop controller s current ae PID parameters alarm limits a output limits After you examine the loop controller parameters and limits you can change them by using the modify parameters command Figure 8 shows the command s format The first word is the block header which indicates the beginning of the read parameters file The second word loop controller address identifies the loop controller whose parameters you want to read When the loop controller acknowledges this command it sends a reply to the PLC Refer to figur 9 The format is the same as the modify parameters format Figure 8 Read Parameter Request Block Transfer Write Word 1 0 0 2 0 A 2 0 0 LOOP CONTROLLER ADDRESS B A Block Header B Loop Controller Address 16 Product Data Loop Controller Interface Module Figure 9 Read Parameter Response File Format Block Transfer Read Word 1 TE 0 A LOOP CONTROLLER ADDRES
7. S B 0 0 Q EN HE E F G H cO OO N O oO A C N 0 mk Oak ede mde AA OO N gt O OI OI O OI OI OI OI OI O OI OI OI O OT GI OD AJ Sol FI O A ol A OI O aT OL Oil CO O O OI O OI O O O oO O OF O OI O O OF O OI O o 15 e A Block Header B Loop Controller Address 01 15 C Proportional Band 1 to 800096 D Integral Time 0 1 to 200 0 Minutes E Derivative Time 0 1 to 100 0 Minutes F Alarm 1 Level 1 99 9 to 102 096 G Alarm 1 Level 2 99 9 to 102 096 H Alarm 2 Level 1 99 9 to 102 096 I Alarm 2 Level 2 99 9 to 102 0 J Alarm 3 Level 1 99 9 to 102 096 K Alarm 3 Level 2 99 9 to 102 096 L Alarm 4 Level 1 99 9 to 102 096 M Alarm 4 Level 2 99 9 to 102 0 N Output Upper Limit 2 0 to 102 0 O Output Lower Limit 2 0 to 102 0 P Implied Decimal Point Upload The upload command allows you to store a loop controller s configuration in the PLC s data table Note that the configuration data is not in readable form You use the download command to transfer this stored configuration back to a loop controller at a later time The upload command permits the PLC to read the loop controller s memory using four block transfer read operations Each block transfer moves a specific section of loop controller memory 64 words each Figurd 10 shows the format of the upload command s Notice that the only difference between th
8. a ial mci eed pm aa Em ki mal d EX Loop Controller Interface Module Cat No 1771 LI Product Data N E N S RR SENS RY S NENNEN S X X SAS SENS m SS S ees S icate with up to 1771 LC1 LC2 LC3 LC4 The module can commun The Loop Controller Interface Module Cat No 1771LD allows a PLC 2 15 loop controllers through an RS 485 serial link 3 or 5 to communicate with single loop PID controllers cat no Description You can configure a loop controller directly from its keypad or download a configuration from the PLC via the interface module Table 1 summarizes the module s functions and commands Product Data Loop Controller Interface Module Table 1 Interface Module Commands Function Command Command Code Change the set point output and Set Control 4000 operating mode Acknowledge alarms Monitor the set point output alarm Loop Status 4000 status and operating mode Change PID parameters alarm limits Modify 0010 and output limits Parameters Examine PID parameters alarm limits Read 0020 and output limits Parameters Transfer a configuration from a Upload 0004 0007 loop controller Transfer a configuration to a loop Download 000C 000F controller Gather data from inputs and outputs Extended Loop 0080 Status Examine error codes Error Record 00F0 Important The loop controller must be in the workstation mode before the interface module can
9. ange from 2 0 to 102 0 Figure 15 Figure 14 Extended Loop Status Command Format Word 1 0 0 8 0 A 2 15 14 13 12 11 10 09 08 07 06 05 04 03 02 01 RS B A Block Header B Loop Controller Select RS reserved Product Data Loop Controller Interface Module Figure 15 Extended Loop Status File Format 0 0 0 3 0 A 15141312 11100908 07060504 030201RS B 0 0 LOOPCONTROLLER ADDRESS C 1 0 2 0 D 1 0 2 0 E 1 0 2 0 F 1 0 2 0 G 1 0 2 0 H 1 0 2 0 1 0 CI 1 amp 2 0 C01 amp 2 J 1 0 2 0 K 1 0 2 0 L 0 0 LOOP CONTROLLER ADDRESS N 1 0 2 0 D 1 0 2 0 E 1 0 2 0 F 1 0 2 0 G 1 0 2 0 H 1 0 2 0 1 0 CI 1 amp 2 0 C01 amp 2 J 1 0 2 0 K 1 0 2 0 L A Block Header H Input E B Loop Controller Acknowledge I Input F RS reserved J Contact In Out C First Loop Controller Requested K Output 1 D Input A L Output 2 E Input B M Implied Decimal Point F Input C N Last Loop Controller Requested G Input D Contact Inputs Cl 1 amp 2 Bit 0 Input 1 0 Open 1 Closed Bit 1 Input 2 0 Open 1 Closed Contact Outputs CO 1 amp 2 Bit 0 Output 1 0 Open 1 Closed Bit 1 Output 2 0 Open 1 Closed 21 Product Data Loop Controller Interface Module Error File 22 When the interface module cannot process a command other than a set control or an extended status command an error file contains an error code identifying the problem
10. change the loop controller s parameters 1771 L1 1771 LC The chart that follows shows you what features you can use with the Compatibility 1771 LI 1771 LC modules you have 1771 LC Series A 1771 LC Series B 1771 Ll Rev A Set Control Set Control Loop Status Loop Status 1771 Ll Rev B Set Control Set Control Loop Status Read Modify Parameters Loop Status Ext Loop Status Upload Download For more detailed loop controller information refer to the Loop Controller User s Manual publication 1771 6 5 42 LED Indicators Keying Bands Product Data Loop Controller Interface Module Three LED indicators on the front of the module indicate the module s current operating status Figure 1 Figure 1 Loop Controller Interface Module MOD FAULT red LED Indicates either a block transfer fault or an addressing problem CHANNEL ACTIVE yellow LED Blinks during normal module operation Lights when the module recieves data from a loop controller Is off when the module sends data to a loop controller MOD ACTIVE green LED Lights whenever power is applied and the module passes its power up test on Kk j stulalols ste WH HO HH S A E Swing Arm Cat No 1770 WA 1797 You use the keying bands supplied with the module to key the backplane to accept only the loop controller interface module The keying bands on the upper backplane connector must correspond with the slots on the module
11. cond word station select value of 0000 e third word the number of the last loop controller e g for five loop controllers the value is 0005 values range from 0001 to 0015 fourth word reserved do not use Changing Loop Controller Parameters Through the PLC You use the set control command to change certain loop controller parameters Refer to figurd 4 To change a set point value for example you use the station select word to select the loop controller to receive the new set point e use the set control word of the selected loop controller to indicate that a new value is being entered and that the new value is a set point a place the loop controller in the automatic mode e enter the new set point Product Data Loop Controller Interface Module Acknowledging Alarms from the PLC If a configured alarm condition develops the alarm indicator on the front of the loop controller flashes Also the corresponding alarm bits are set to 1 in the alarm status word loop status file The indicator continues to flash until you acknowledge the alarm You acknowledge the alarm either by pressing the ACK key on the loop controller or through the PLC Once you acknowledge the alarm the indicator stops flashing but remains lit until you correct the problem Refer to the Loop Controller User s Manual publication 1771 6 5 42 for additional information To acknowledge an alarm from the PLC set bit 7 alarm ackno
12. e commands is the command code 17 Product Data Loop Controller Interface Module When the loop controller acknowledges the PLC s request it begins sending data Refer to figure 11 The interface module calculates a checksum value as each block of data transfers from the loop controller to the PLC This checksum is used to verify that no data sent to the PLC was altered Caution Do not alter the data that you transferred to the PLC If you alter the data and download it to the loop controller without proper testing unexpected process control could result Figure 10 Upload Command Format Block Transfer Write Word 1 0 0 0 4 A 2 0 0 LOOP CONTROLLER ADDRESS B A Block Header 0004 0005 0006 and 0007 B Loop Controller Address Figure 11 Upload File Format Block Transfer Read Word 1 0 0 2 0 A 2 0 0 LOOP CONTROLLER ADDRESS B 3 0 5 0 0 C 63 64 A Block Header 0004 0005 0006 and 0007 B Loop Controller Address C Beginning of Configuration Data D End of Configuration Data E Checksum Download The download command enables the PLC to send back to a loop controller the contents of memory previously uploaded to the data table The download command is actually four commands as shown in figure 12 The PLC uses the four block transfer write operations to transfer the memory contents back to the loop controller The loop controller should be in the manual mode when you transfer data from the
13. ed New value select 0 output 1 setpoint Reserved Alarm acknowledge NOP WYP O Loop status is the module s response to a set control command from the PLC Loop status is also the module s default response when no set control command is issued The data in this file represents each loop controller s current set point measurement output alarms and status Loop Status File The first four words of the loop status file contain loop controller selection and diagnostic information that applies to all loop controllers connected to the interface module Figurd 5 The first word the block header indicates that this is the beginning of the loop status file The second word loop controller select acknowledge shows which loop controllers responded to the most recent set control command The third word the no response word indicates which loop controllers did not respond when polled Note that bit O of words two and three is reserved The fourth word the diagnostic word shows which loop controller has an improper value in the last set control command Each loop controller has a four word reserved area of memory in the loop status file The first word in each loop controller s area is the alarm status word which indicates the loop controller s current status The three remaining words contain three values that reflect the loop s current operating values set point measurement and output These values are fourdig
14. ing RS 485 multi drop up to 4000 ft Between 12 and 14 Between 16 and 18 1987 Allen Bradley Company Inc PLC is a registered trademark of Allen Bradley Company Inc 23 ALLEN BRADLEY NIE AROCKWELL INTERNATIONAL COMPANY With offices in major cities worldwide WORLD EUROPE MIDDLE HEADQUARTERS EAST AFRICA Allen Bradley HEADQUARTERS 1201 South Second Street Allen Bradley Europe B V Milwaukee WI 53204 USA Amsterdamseweg 15 Tel 1 414 382 2000 1422 AC Uithoorn Telex 43 11 016 The Netherlands FAX 1 414 382 4444 Tel 31 2975 43500 Telex 844 18042 FAX 31 2975 60222 Publication 1771 2 109 October 1987 Supersedes Publication 1771 2 109 February May 1987 As a subsidiary of Rockwell International one of the world s largest technology companies Allen Bradley meets today s challenges of industrial automation with over 85 years of practical plant floor experience More than 11 000 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 B
15. it BCD numbers which represent percent of scale The values can range from 2 0 to 102 0 Negative values have their most significant bit Set The module continuously polls each loop controller for its current status When a loop controller responds the interface module places the updated status values in the loop controller s area When a loop controller does not respond to a module s status request its area contains all zeroes If a loop controller does not respond to a status request after three tries the interface module sets a bit in the no response word 11 Product Data Loop Controller Interface Module Figure 5 Loop Status File Format Block Transfer Read Word f Loop Status Values 0D 4 0 go 0 A 2 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 RS B 3 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 RS C 4 DIAGNOSTIC WORD D 5 LOOP CONTROLLER ALARM LOOP CONTROLLER STATUS E 6 S 1 0 2 0 F 7 S 1 0 2 0 G 8 S 1 0 2 0 H I 61 LOOP CONTROLLER ALARM LOOP CONTROLLER STATUS J 62 S 1 0 2 0 K 63 S 1 0 2 0 L 64 S 1 0 2 0 M I A Block header G Measurement value LC 1 B Loop controller select H Output value LC 1 acknowledge RS reserved I Implied decimal point C No response CRC RS reserved J Alarm Status word LC 15 Diagnostic word K Setpoint value LC 15 E Alarm status word LC 1 L Measurement value LC 15 Setpoint value LC 1 M Output value LC 15 12 Product Data
16. module verifies that each BCD value is valid and falls within a specified range The file s first word is the block header which indicates the beginning of the modify parameters file The second word loop controller address identifies the loop controller whose PID parameters you want to alter Words three through five contain the PID parameters while words six through 13 contain alarm limits Words 14 and 15 hold the upper and lower output limit values When the loop controller receives the command from the PLC it sends a modify parameter acknowledge value back to the PLC Refer to figure 7 If an error occurs the error file displays the appropriate error code Product Data Loop Controller Interface Module Figure 6 Modify Parameter File Format Block Transfer Write Word f Modify Parameter Values 1 0 0 1 0 A 2 0 0 LOOP CONTROLLER ADDRESS B 3 0 5 0 0 C 4 0 0 1 i 0 D 5 0 0 0 5 E 6 0 4 0 0 F 7 0 6 0 0 G 8 0 4 0 0 H 9 0 6 0 0 I 10 0 4 0 0 J 11 0 6 0 0 K 12 0 4 0 0 L 13 0 6 0 M 14 0 9 8 0 N 15 0 1 5 0 0 P A Block Header B Loop Controller Address 01 15 C Proportional Band 1 to 8000 D Integral Time 0 1 to 200 0 Minutes E Derivative Time 0 1 to 100 0 Minutes F Alarm 1 Level 1 99 9 to 102 0 G Alarm 1 Level 2 99 9 to 102 0 H Alarm 2 Level 1 99 9 to 102 0 I Alarm 2 Level 2 99 9 to 102 0 J Alarm 3 Level 1 99 9 to 102 0
17. radley 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 1 414 382 2000 28 Watson Road 5X1 Telex 43 11 016 Hong Kong Canada FAX 1 414 382 2400 Tel 852 887 4788 Tel 1 519 623 1810 Telex 780 64347 FAX 1 519 623 8930 FAX 852 510 9436 PN 955102 74 Printed in USA
18. tion from the end of each wire 4 Connect the wires to the module as shown in figurd 3 5 Repeat steps 1 through 4 for the cable end to be connected to the loop controller s terminal block Product Data Loop Controller Interface Module Figure 2 Cable Preparation Insulated wire 7 pt trimmed nti a 4 11 e SUC a eB A B ad insulation dr Off wire P diia n i i z 2 Insulated ETT Rd c N wire eS ER m Foil reer ted 4 41 01 Insulation Stripped from cable Product Data Loop Controller Interface Module Figure 3 Loop Controller Interface Module Wiring Loop Controller Interface Module 1771 LI iih M gt Wm ae BEI e enek a m mm U d wl d TE Wiring Legend Li Module LC Module A 24 er 25 1 22 LOOP Loop Loop Controller Controller Controller 1771 LC 1771 LC 1771 LC TIAA a ee CELDTI Shield Optional ATORI Optional Optional 14788 Electrostatic Damage To prevent static damage we construct test and pack our products in a static free environment We ship our products that require individual protection in bags that are sealed and shielded from static When removing a product from a bag or disassembling a device do so in a static safe environment Product Data Loop Controller Interface Module
19. ues are four digit BCD numbers which represent percent of scale These values can range between 2 0 and 102 0 Negative values have their most significant bit set Product Data Loop Controller Interface Module The first word of the set control file is the block header Refer to figurd 4 This word 4000 indicates that this is the beginning of the set control file The second word is loop controller select You use this word to select the loop controller whose parameters you want to change Note that the least significant bit is reserved In the third word you place the address of the last loop controller connected to the interface module The fourth word is reserved Next the file contains three words for each loop controller 15 loop controllers maximum The fifth word is the address of the first loop controller Set control the sixth word allows you to select the changes for loop controller one The seventh word holds the new set point or output value The second loop controller s section of memory three words begins with word eight Setting the Last Controller Address To ensure optimum loop performance you must consecutively number the loop controllers connected to the serial link Begin with number one and do not skip any numbers when you number them You specify the number of loop controllers in the set control file Refer to figure 4 Initially the file must contain a first word block header of 4000 a se
20. wledge of the set control word for that loop controller Monitoring the Loop Controller s Configuration Whenever you advance past the loop controller s configuration passcode the front panel change indicator bit 0 of the loop controller alarm status word is set You acknowledge the advance past the configuration passcode by setting the user interface acknowledge bit of the set control command bit 2 This resets bit O of the loop status word Product Data Loop Controller Interface Module Figure 4 Set Control Format Block Transfer Write Word f Set Control Values l 4 0 0 0 A 2 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1RS B 3 0 0 LAST CONTROLLER ADDRESS C 4 RESERVED D 5 0 0 0 1 E 6 0 0 SET CONTROL F 7 S l 0 2 0 G H 47 0 0 l 5 1 48 0 0 SET CONTROL J 49 S 1 0 2 0 K H A Block header G New setpoint or output B Loop controller select value S sign bit LC 1 RS reserved C Last loop controller address H Implied decimal point D Reserved word I Loop controller 15 address E Loop controller 1 address J Set Control Word LC 15 F Set control word LC 1 K New setpoint or output value S sign bit LC 15 10 Loop Status Product Data Loop Controller Interface Module Set Control Word Bit Definitions Bit Definition New value specified A M select 0 manual 1 auto User interface acknowledge R L setpoint select 0 local 1 remote Reserv
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