AB Quality Allen-Bradley 1771-DE User manual

User
Manual
Absolute Encoder
Module
(Cat. No. 1771-DE)
AllenĆBradley

Using This Manual 1Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 1Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
What This Manual Contains 1Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audience 1Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Warnings and Cautions 1Ć2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Su ary 1Ć2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introducing the Absolute Encoder Module 2Ć1. . . . . . . . . . . . .
Chapter Objectives 2Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Exa ple
Applications 2Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Functions 2Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Co patible Processors 2Ć2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Co patible Encoders 2Ć2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
State of Outputs Upon Loss of Input Power 2Ć2
. . . . . . . . . . . . . . . . . .
Module Description 2Ć3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrostatic Discharge 2Ć5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 2Ć6
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Su ary 2Ć7
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Configuring and Installing Y our Module 3Ć1. . . . . . . . . . . . . . .
Chapter Objectives 3Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrostatic Discharge 3Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting Configuration Plugs 3Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Response
to External Fault 3Ć4. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Keying 3Ć4
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Require ents 3Ć5
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WiringĆAr Connections 3Ć8
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the Module 3Ć11
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Processor Communication 4Ć1. . . . . . . . . . . . . . . . . .
Chapter Objectives 4Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Transfer 4Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BlockĆtransferĆwrite
Data 4Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
WriteĆData Throughput Ti e 4Ć4
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
BlockĆtransferĆread
Data 4Ć4. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Progra ing Exa ple 4Ć5
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Progra ing Considerations 4Ć7
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Su ary 4Ć7
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Table of Contents

Table of Contentsii
Offset Feature 5Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Offset Feature 5Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Offset Words 5Ć2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Progra ing
Considerations with Of fset 5Ć6. . . . . . . . . . . . . . . . . . .
Troubleshooting 6Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Chapter Objectives 6Ć1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Causes of BlockĆtransfer Errors 6Ć1
. . . . . . . . . . . . . . . . . . . . . . . . . .
Errors
Indicated by Diagnostic Bits 6Ć2. . . . . . . . . . . . . . . . . . . . . . .
Su ary 6Ć2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BlockĆtransfer Ti ing AĆ1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BlockĆtransfer Ti ing for PLCĆ2 Fa ily Processors AĆ1
. . . . . . . . . . . .
BlockĆtransfer Ti ing for PLCĆ3 Fa ily Processors AĆ8
. . . . . . . . . . . .
Application Considerations BĆ1
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Application Considerations BĆ1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BlockĆtransfer Ladder Diagram Examples CĆ1. . . . . . . . . . . . .
Bidirectional BlockĆtransfer for PLCĆ2 Fa ily Processors CĆ1. . . . . . . .
Bidirectional BlockĆtransfer for PLCĆ3 Processors CĆ4
. . . . . . . . . . . . .
ReadĆonly BlockĆtransfer for PLCĆ2 Fa ily Processors CĆ6
. . . . . . . . .
Bit and Word Descriptions of Block-transfer Data DĆ1. . . . . . .
Block-transfer-write Data DĆ1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block-transfer-read
Data DĆ2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connection Diagrams for AllenĆBradley Encoders EĆ1. . . . . .
Connection Diagra s for AllenĆBradley Encoders EĆ1. . . . . . . . . . . . .
0 to 359Ćcount, 10Ćbit, BCD, SingleĆended Output EĆ1
. . . . . . . . . . . . .
0 to 255Ćcount, 8Ćbit, Standard Gray, SingleĆended Output EĆ3
. . . . . . .
0 to 359Ćcount, 10Ćbit, BCD, SingleĆended Output, Latching EĆ4
. . . . . .
Glossary FĆ1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

Chapter 1
1Ć1
Using This Manual
Read this chapter to familiarize yourself with this manual. It tells you
how to use the manual properly and efficiently.
This manual contains 5 chapters and 6 appendices:
Chapter
Appendix
Title What's Covered
1 Using This Manual Manual' s purpose, audience, and contents
2 Introducing the Absolute
Encoder Module
Module description, features, and hardware
co ponents
3
Configuring and Installing
Y our Module
Feature selection and installation procedures
4 Module/Processor
Co unication
W ords and file para eters of blockĆtransfer
data
5Of
fset Feature Progra ing to co pensate for shaft of fset
6 Troubleshooting T
roubleshooting guide
A Block-transfer T i ing Instructions for deter ining blockĆtransfer
ti ing
B
Application Consideration Encoder shaft speed
C Block-transfer Ladder
Diagra Exa ples
Exa ples of blockĆtransfer progra ing
D Biat and W ord Description
of Block-transfer Data
Details of blockĆtransfer file data
E Glossary
F Index
In this manual we assume that you know how to:
program and operate an Allen-Bradley programmable controller
program block-transfer instructions
Chapter Objectives
What This Manual Contains
Audience

Using This Manual
Chapter 1
1Ć2
If you do not know how to do either of these, read the user’s manual of
your processor. Refer to our Publications Index (publication SD499) for a
complete list of publications.
Throughout this manual we include 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.
CAUTION: tells you when machinery may be damaged if
procedures are not followed properly.
This chapter told you how to use this manual efficiently. The next chapter
introduces you to the absolute encoder module.
Warnings and Cautions
Summary

Chapter 2
2Ć1
Introducing the Absolute Encoder Module
This chapter describes:
example applications of the absolute encoder module
functions of the module
Allen-Bradley processors compatible with the absolute encoder module
encoders you can use with the module
module specifications
The absolute encoder module is usually used for:
absolute-position feedback
high-speed response to position based on encoder values
immunity to loss of position from power loss or power interruptions
The Absolute Encoder Module (cat. no. 1771-DE) is 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
control up to eight high-current outputs based on comparisons between
encoder position and your preset values
provide throughput for all eight outputs in less than 200 us
communicate with the programmable controller through block transfers
return the status of outputs and the position of an absolute encoder to
the programmable controller
In addition, the module can switch 2A DC per output with no derating
when all outputs are on, allowing 16A continuous per module.
Chapter Objectives
Example Applications
Module Functions

Introducing the Absolute Encoder Module
Chapter 2
2Ć2
You can use the absolute encoder module with any Allen-Bradley
programmable controller that uses block-transfer programming in both
local and remote 1771 I/O systems. Processors that are compatible with
the module include:
Mini PLC-2 (cat. no. 1772-LN3)
PLC-2/20 (cat. no. 1772-LP1, -LP2)
PLC-2/30 (cat. no. 1772-LP3)
PLC-3 (cat. no. 1775-L1, -L2)
Mini-PLC-2/15 (cat. no. 1772-LV)
Mini-PLC-2/05 (cat. no. 1772-LS, -LSP)
You can use Allen-Bradley absolute encoders that use up to 12 bits with
the absolute encoder module. Allen-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 that have the
following specifications:
single-ended or differential encoder output signals
TTL-compatibility (output drivers)
capability of sinking 11mA (single-ended) or 18mA (differential) per
channel
BCD, natural binary, or standard Gray code format
You can select the state in which the outputs will be if the module loses
input power. A configuration plug on the right printed-circuit board
allows the outputs to:
turn off
remain in their state at loss of input power
Compatible Processors
Compatible Encoders
State of Outputs Upon Loss of
Input Power

Introducing the Absolute Encoder Module
Chapter 2
2Ć3
The next four sections give a description and specifications of the
absolute encoder module.
Status Indicators
The module has 10 LED status indicators (Figure 2.1):
Eight output status indicators (one for each output) light when the
corresponding 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 power-up.
Figure 2.1
Status
Indicators
ABSOLUTE
ENCODER
MODULE
Active
0
1
2
3
4
5
6
7
Fault
Output status
Indicators
Status Indicators
Output Fuses
The module has eight 3A rectifier fuses (one per output) located on the
right printed-circuit board. Figure 2.2 shows the fuse locations.
Module Description

Introducing the Absolute Encoder Module
Chapter 2
2Ć4
Figure 2.2
Fuse
Locations
F1 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 differential output encoders)
or
common terminals (used with single-ended output encoders)

Introducing the Absolute Encoder Module
Chapter 2
2Ć5
Figure 2.3
Terminal
Identification
1
2
3
4
5
6
7
8
9
10
11
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
Output Supply (+5 to 24V dc)
Output 0
Output 1
Output 2
Output 3
Output Co on (+5 to 24V dc)
Output Co on (+5 to 24V dc)
Not Used
Output Supply (+5 to 24V dc)
Output 4
Output 5
Output 6
Output 7
Output Co on (+5 to 24V dc)
Output Co on (+5 to 24V dc)
Not Used
Bit 10
Bit 10 / Co on
Bit 11
Bit 11 / Co on
Input Co on (+5V dc)
Bit 0
Bit 0 / Co on
Bit 1
Bit 1 / Co on
Bit 2
Bit 2 / Co on
Bit 3
Bit 3 / Co on
Bit 4
Bit 4 / Co on
Bit 5
Bit 5 / Co on
Bit 6
Bit 6 / Co on
Bit 7
Bit 7 / Co on
Bit 8
Bit 8 / Co on
Bit 9
Bit 9 / Co on
Input Supply
(+5V dc)
12832
Left
Wiring
Ar
Right
Wiring
Ar
For Outputs
0 - 3
For Outputs
4 - 7
Electrostatic discharge can damage integrated circuits or semiconductors
in this module if you touch backplane connector pins. It can also damage
the module when you set configuration plugs or switches inside the
module. Avoid electrostatic discharge by observing the following
precautions:
Touch a grounded object to discharge yourself before handling the
module.
Do not touch the backplane connector or connector pins.
When you configure and replace internal components, do not touch
other circuit components inside the module. If available, use a
static-safe workstation.
When not in use, keep the module in its static-shield bag.
Electrostatic Discharge