User
Manual
Absolute Encoder
Module
(Cat. No. 1771-DE)
AllenĆBradley
Страница 1: ...User Manual Absolute Encoder Module Cat No 1771 DE Allen Bradley...
Страница 2: ...Electrostatic Discharge 2 5 Specifications 2 6 Summary 2 7 Configuring and Installing Your Module 3 1 Chapter Objectives 3 1 Electrostatic Discharge 3 1 Setting Configuration Plugs 3 1 Response to Ex...
Страница 3: ...onsiderations B 1 Block transfer Ladder Diagram Examples C 1 Bidirectional Block transfer for PLC 2 Family Processors C 1 Bidirectional Block transfer for PLC 3 Processors C 4 Read only Block transfer...
Страница 4: ...ule Processor Communication Words and file parameters of block transfer data 5 Offset Feature Programming to compensate for shaft offset 6 Troubleshooting Troubleshooting guide A Block transfer Timing...
Страница 5: ...e special notes to alert you to possible injury to personnel or damage to equipment under specific circumstances WARNING tells you when people may be injured if procedures are not followed properly CA...
Страница 6: ...an intelligent module that provides high speed response to machine position independently of the programmable controller scan It can monitor the position of an absolute encoder that has up to 12 bits...
Страница 7: ...en Bradley encoders with the following bulletin numbers are compatible with the absolute encoder module Bulletin 845A Bulletin 845B Bulletin 845C The module is also compatible with absolute encoders t...
Страница 8: ...output circuitry is energized One green ACTIVE indicator lights when the module is powered and functioning One red FAULT indicator lights when the module detects a fault and momentarily lights at powe...
Страница 9: ...F2 F3 F4 F5 F6 F7 F8 Right Board 13303 Terminal Identification Figure 2 3 identifies each terminal of the absolute encoder module The bit x common terminals refer to not bit x terminals uses with diff...
Страница 10: ...on Bit 6 Bit 6 Common Bit 7 Bit 7 Common Bit 8 Bit 8 Common Bit 9 Bit 9 Common Input Supply 5V dc 12832 Left Wiring Arm Right Wiring Arm For Outputs 0 3 For Outputs 4 7 Electrostatic discharge can dam...
Страница 11: ...ncoders Up to one part in 999 with BCD encoders Output Current Rating 2A sourced per output no derating with all outputs on High true Logic From totem pole open collector or differential line drivers...
Страница 12: ...lative Humidity 5 to 95 without condensation New Write data Throughput Time 4 7 ms Keying for slot 0 only Between 2 and 4 Between 26 and 28 Torque for wiring arm connections 9 inch pounds This chapter...
Страница 13: ...not touch other circuit components inside the module If available use a static safe work station When not in use keep the module in its static shield bag CAUTION Electrostatic discharge can degrade pe...
Страница 14: ...E14 E15 E1 E2 E3 E4 E5 E6 E7 E8 E9 E10 E11 E12 Config Configuration Plug Settings uration Plug Encoder Signal Mode Encoder Format Gray Encoder Rotational Direction Single ended Differ ential Natural B...
Страница 15: ...Down Selecting Encoder Format and Input Signal Mode Set configuration plugs E1 through E12 on the left board to match the signal mode of each encoder input channel to the encoder Set configuration plu...
Страница 16: ...choose the state of the outputs if the module loses input power The plug is factory set for the outputs to turn off if input power is lost up position If you want the outputs to remain in their state...
Страница 17: ...es the encoder module keying positions for slot 0 Figure 3 3 Keying Positions 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0 3 2 3 4 3 6 2 4 6 8 1 0 1 2 1 4 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0 3 2 3...
Страница 18: ...n parallel to reduce the voltage drop between the power supply and the encoder Figure 3 4 Do not source current such as from a power supply into the encoder input terminals of the module Doing so can...
Страница 19: ...nnect another wire between terminal 6 or 7 and terminal 14 or 15 Figure 3 5 Connection Diagram for Output Devices 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Output Supply 5 to 24V dc Output...
Страница 20: ...status to change unpredictably until a valid write to the module occurs If swing arm power is lost turn on the power up bit and disable all outputs until a valid write occurs Connecting a Single ended...
Страница 21: ...tinue in this manner until you make all bit connections Output Circuitry If the encoder uses less than 12 bits jumper the unused input terminals Connecting a Differential Output Encoder Figure 3 7 is...
Страница 22: ...t 1 Bit 2 Bit 2 Other bit connections not shown Continue in this manner until you make all bit connections Output Circuitry If the encoder uses less than 12 bits jumper the unused input terminals Conn...
Страница 23: ...ry and or equipment damage due to possible unexpected operation WARNING Install the module in the I O chassis so that both halves of the module are in the same I O group Failure to observe this rule w...
Страница 24: ...chapter told you how to select features and set configuration plugs on the absolute encoder module and described the power requirements keying wiring and installation of the module In the next chapter...
Страница 25: ...6 PLC 2 20 1772 6 8 1 PLC 2 30 1772 6 8 3 PLC 3 1772 6 4 1 You write data to the module in blocks You can write 5 10 15 or 20 words in one block transfer operation Each block of five words is associa...
Страница 26: ...reset 0A Preset 0B Preset 1A Preset 1B Word 1 2 3 4 5 OE ZT OE ZT Control word for Outputs 2 and 3 Preset 2A Preset 2B Preset 3A Preset 3B 6 7 8 9 10 OE ZT OE ZT Control word for Outputs 4 and 5 Prese...
Страница 27: ...lthough comparisons to the presets may be true if you don t set this bit the output is not turned on The upper byte of control word 1 is associated with output 1 The format of this byte is similar to...
Страница 28: ...ata from the module and transfers it to its data table in two read data words The module sends only two read data words in any one block transfer read operation The format of these words is shown in F...
Страница 29: ...finds them one at a time Once you correct a preset the module continues to identify any non BCD preset Word 2 indicates the current absolute position of the encoder in BCD Presets are interpreted by...
Страница 30: ...value of 329 Then you set the less than bit for preset A the greater than bit for preset B the ZT bit OE bit In either case you must set bit 6 ZT to indicate that the output should be on if either com...
Страница 31: ...G When the block lengths of bidirectional block transfer instructions are set to unequal values do not enable the rung containing the alternate instruction until the done bit of the first transfer is...
Страница 32: ...value using either of two equations depending on whether you use the 0 machine position or the 0 encoder position as your reference To calculate an offset value from a 0 encoder position use this equ...
Страница 33: ...12 The offset is 3 584 At machine shaft position 0 encoder position is 3 584 The offset is 512 13522 The equation from 0 encoder position is 4 096 512 3 584 The offset is 3 584 The equation from 0 mac...
Страница 34: ...ue of the offset Bit 17 of this word is the sign bit It indicates whether the offset is negative or positive Set bit 17 if the offset is negative reset it if the offset is positive The second offset w...
Страница 35: ...set 5A 15 Preset 5B OE ZT 16 OE ZT Control Word for Outputs 6 and 7 17 Preset 6A 18 Preset 6B 19 Preset 7A 20 Preset 7B 21 Offset Value 22 No of Encoder Positions S A Write data words B Format of cont...
Страница 36: ...identifies that the offset value is greater than the number of encoder positions Bit 0 identifies which offset word is in non BCD format when bit 5 is also set If bit 0 is set the word containing the...
Страница 37: ...dule s offset feature For PLC 2 family processors do not enable the read and write block transfers in the same scan when you use the offset feature An example program enabling the instructions in sepa...
Страница 38: ...0 04 U 077 OFF00 077 OFF00 022 122 06 07 022 07 122 07 READ FILE DONE BIT 122 DONE BIT 044 07 15 0044 17 0044 15 EN BLOCK XFER READ DATAADDR MODULE ADDR BLOCK LENGTH FILE 0041 220 22 0202 0227 DN EN F...
Страница 39: ...write done bit 122 06 and the valid BCD data bit 200 04 to unlatch 077 00 and begin the read only operation Rung 3 This rung contains the block transfer read instruction conditioned by the read done...
Страница 40: ...r processor module ACTIVE FAULT Module has detected a hardware fault in its power up diagnostic routine Return module for repair ACTIVE FAULT Module is not receiving DC power from the chassis backplan...
Страница 41: ...rd contains the diagnostic bits If this bit is set Then 07 The module is not receiving 5V from the input power supply check the supply and the connections between the supply and the module 06 The modu...
Страница 42: ...ansfer modules in the system Also assume that the encoder module is transferring 20 words in a write operation and two words in the alternate read operation The method of calculating the worst case ti...
Страница 43: ...et between the remote distribution panel and remote I O chassis for a baud rate of 57 6kBd or 5 000 cable feet at 115kBd 3 Calculate the worst case system time ST between transfers ST Sum of transfer...
Страница 44: ...A S 1 7 7 1 D E Rack 2 1 7 7 1 A S 1 7 7 1 D E Rack 3 1 7 7 1 A S 1 7 7 1 D E Rack 4 108121 I We want to find the worst case time between two consecutive block transfer read operations from the same...
Страница 45: ...5 20 13 ms 101 ms write TR PS PIO 2 RIO 0 5W 4 ms 20 2 2 28 0 5 2 4 ms 83 ms read 3 Calculate the worst case system time ST between 2 consecutive block transfer read operations ST 4TW 4TR 4 101 4 83...
Страница 46: ...k transfer time T for the read or write operation T 0 08 ms word x number of words transferred 3 Calculate the worst case system time ST between transfers ST PS PIO T 1 read T 2 read T 3 read PS PIO T...
Страница 47: ...7 7 1 D E Rack 3 1 7 7 1 A L 1 7 7 1 D E Rack 4 1 7 7 1 A L 1 7 7 1 D E Rack 2 10813 I Solution Program length 4K words Number of chassis 4 1 assigned rack number per chassis Number of block transfer...
Страница 48: ...reads ST 2PS 2PIO 4T read 4T write 2 20 2 2 4 16 4 1 6 40 4 64 6 4 51 04 ms This is the worst case time between two consecutive block transfer read operations in the 4 chassis local configuration des...
Страница 49: ...ansferred W 2 read 20 write 3 Calculate the block transfer time T for the read and write operation T 0 08 ms word x 2 words read 0 16 ms read T 0 08 ms word x 20 words write 1 6 ms write 4 Calculate t...
Страница 50: ...er block transfer modules on the same scanner channel that are enabled simultaneously Block transfer times typically are similar regardless of the type of block transfer module the number of words tra...
Страница 51: ...l 1 contains five I O chassis with a total of seven block transfer modules including one encoder module channel 2 contains two I O chassis with no block transfer modules channel 3 contains two I O cha...
Страница 52: ...values have been added 1 2 3 4 1 40 52 54 58 2 67 68 76 3 98 99 4 123 Time ms Active I O channels containing one or more block transfer modules Number of active I O channels 3 Number of active I O cha...
Страница 53: ...ample values have been added Program Scan Time program 2 5 ms 1K words x 20K words 2 5 x 20 50 ms Scanner Scan Time read or write 512 ms for channel 1 and 77 ms for channel 3 from Step 3 Read Write Ti...
Страница 54: ...If you control Then K for rps OR K for rpm 8 outputs 5000 300 000 6 outputs 6493 389 610 4 outputs 9009 540 540 2 outputs 14 084 845 070 For example if you control eight outputs with a 0 to 359 count...
Страница 55: ...giving 360 increments or one revolution every 79 ms This is equal to about 758 rpm In the second example Figure B 2 we assume a more typical shaft speed of 60 rpm or one revolution per second The enc...
Страница 56: ...least significant bit LSB or bit 0 of a BCD or binary encoder The LSB changes with every change in encoder position one increment of shaft rotation This bit has the highest input frequency of all enc...
Страница 57: ...tion and the process then repeats Let s look at the first example where the encoder is operating near maximum speed and control is maintained over a one count resolution Comparing the input and output...
Страница 58: ...tput to turn on at position 100 for one PC scan the PC might see a position value of 099 while the output on bit is set The comparisons will be performed correctly but the status of the outputs read b...
Страница 59: ...045 with the understanding that the change of output could occur a few increments after those positions Hardware RC filtering in the module input circuitry is designed to attenuate high frequency noi...
Страница 60: ...2400 2677 DN EN FILE TO FILE MOVE COUNTER ADDR POSITION FILE LENGTH FILE A 0061 001 002 2600 2601 DN FILE R RATE PER SCAN 2500 2501 002 047 07 147 07 147 07 0061 17 0061 15 EN BLOCK XFER WRITE DATAADD...
Страница 61: ...th files appear to be 64 words long only two words are used for read operations and 20 words are used for write operations The remaining words are available for storage File 2600 2700 This is the addr...
Страница 62: ...0 9E9E 002 0054 0000 003 0000 0044 004 0000 0045 005 0000 0089 006 0000 9E9E 007 0000 0090 008 0000 0134 009 0000 0135 010 0000 0179 011 0000 9E9E 012 0000 0180 013 0000 0224 014 0000 0225 015 0000 02...
Страница 63: ...count binary encoder Figure C 3 Example Block transfer Rungs for PLC 3 Processors EN BTR BLOCK XFER READ RACK GROUP MODULE 002 3 0 LOW FB015 0001 DN 0 FB010 0040 ER DATA LENGTH CNTL WB010 0040 15 CNTL...
Страница 64: ...s located in I O group 3 Module 0 low The module is in the low slot of the I O group Two slot modules are addressed as being in slot 0 Data FB015 0001 FB015 0011 This is the address of the first word...
Страница 65: ...00024 2560 3071 9E9E 3072 3583 3584 4095 0000 00032 0000 0000 0000 0000 0000 0000 0000 0000 00040 In this example Word 1 shows that output 1 is energized Word 2 indicates the current encoder position...
Страница 66: ...RITE DATAADDR MODULE ADDR BLOCK LENGTH FILE 0041 220 00 0202 0301 DN EN FILE TO FILE MOVE COUNTER ADDR POSITION FILE LENGTH FILE A 0043 001 020 0202 0225 DN FILE R RATE PER SCAN 0200 0223 020 022 06 1...
Страница 67: ...fer write operation Rung 2 This rung examines the write done bit 122 06 and the valid BCD data bit 200 04 to unlatch 077 00 and begin the read only operation Rung 3 This rung contains the block transf...
Страница 68: ...on bit for preset 1B 13 Comparison bit for preset 1B 12 Comparison bit for preset 1A 11 Comparison bit for preset 1A 10 Comparison bit for preset 1A 07 OE Output enable bit set this bit if you want ou...
Страница 69: ...14 Preset value A for output 5 15 Preset value B for output 5 17 Preset value A for output 6 18 Preset value B for output 6 19 Preset value A for output 7 20 Preset value B for output 7 Read data Wor...
Страница 70: ...nary or hexadecimal code that indicates which of the 16 presets is not in BCD format Refer to the next section for details of these bits 2 17 through 00 Current absolute position of encoder in BCD Val...
Страница 71: ...Appendix D D 4 If non BCD digit is in word And the binary equivalent is And the Hex error code is Then it is preset 19 7A E 1110 20 7B F 1111...
Страница 72: ...ws you the connections for a Bulletin 845C encoder 0 to 359 count 10 bit BCD single ended output latching encoder Follow these guidelines Make the wht orn wire pin V an open connection The encoder cou...
Страница 73: ...eft Wiring Arm Right Wiring Arm 5V dc Input Supply 13308 Pin R BRN DECADE 1 1 Pin K ORN DECADE 1 2 Pin E YEL DECADE 1 4 Pin A GRN DECADE 1 8 Pin B BLU DECADE 2 1 Pin G VIO DECADE 2 2 Pin C GRAY DECADE...
Страница 74: ...eave pins V and Q unconnected Jumper the unused most significant bit input terminals Figure E 2 Connection Diagram for Allen Bradley Encoder Bulletin 845A Standard Gray 1 2 3 4 5 6 7 8 9 10 11 12 13 1...
Страница 75: ...s up in a clockwise direction Pins P N and V are internally connected on the encoder Pins U Z T and M are internally connected on the encode Encoder output requires 5V DC jumper pins P N and V to pin...
Страница 76: ...1 12 13 14 15 16 17 18 19 20 21 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 Left Wiring Arm Right Wiring Arm 5V dc Input Supply 13310 Pin S D1 1 Pin W D1 2 Pin R D1 4 Pin K D1 8 Pin E D2 1 P...
Страница 77: ...I O module and the processor data table DIFFERENTIAL OUTPUT ENCODER An encoder using differential line driver output devices that have a bit x and bit x output signals ENCODER DATA SETTLING TIME The t...
Страница 78: ...e to perform within one increment of shaft rotation for example turn on an output at position 007 and off at position 008 PRESET VALUE The value against which the absolute position of the encoder is c...
Страница 79: ...s 3 10 Power Supplies 3 5 Control Words 4 3 D 1 D Diagnostic Bits D 3 E Encoder 3 9 Format 2 2 3 3 Input Signal Mode 3 3 Example Applications 2 1 F Fuses 2 3 2 6 G Glossary F 1 I Installation 3 11 K K...
Страница 80: ...Croatia Cyprus Czech Republic Denmark Ecuador Egypt El Salvador Finland France Germany Greece Guatemala Honduras Hong Kong Hungary Iceland India Indonesia Ireland Israel Italy Jamaica Japan Jordan Ko...
