AB Quality ALLEN-BRADLEY 1771-QB User manual

Linear Positioning Module
User Manual
Cat. No. 1771-QB

Because of the variety of uses for the products described in this publication,
those responsible for the application and use of this control equipment 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.
The illustrations, charts, sample programs and layout examples shown in this
guide are intended solely for purposes of example. Since there are many
variables and requirements associated with any particular installation, the
Allen-Bradley Company, Inc. 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 the Application,
Installation and Maintenance of Solid State Control” (available from your local
Allen-Bradley office) describes some important differences between solid-state
equipment and electromechanical devices which should be taken into
consideration when applying products such as those described in this
publication.
Reproduction of the contents of this copyrighted manual, in whole or in part,
without written permission of the Allen-Bradley Company Inc. is prohibited.
Throughout this manual we use notes to make you aware of safety
considerations:
ATTENTION: Identifies information about practices or
circumstances that can lead to personal injury or death, property
damage or economic loss.
Attentions help you:
identify a hazard
avoid the hazard
recognize the consequences
Important: Identifies information that is especially important for
successful application and understanding of the product.
PLC is a registered trademark of Allen-Bradley Company, Inc.
Important User Information

Preface P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Organization of the Manual P1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Audience P2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related
Publications P2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Related Software P2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Frequently Used Terms P3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Introducing the Linear Positioning Module 11. . . . . . . . . . . .
What is the Linear Positioning Module? 11. . . . . . . . . . . . . . . . . . . .
Product
Compatibility 12. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transducers 12
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Servo and Proportional Valves 13
. . . . . . . . . . . . . . . . . . . . . . . .
System Overview 14
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Positioning Concepts 21. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Axis Motion 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
ClosedLoop
Positioning 22. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Linear Displacement Transducer 22
. . . . . . . . . . . . . . . . . . . . . . .
A
Simple Positioning Loop 23. . . . . . . . . . . . . . . . . . . . . . . . . . .
Proportional
Gain 24. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Feedforwarding 25
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Integral Control (Reset Control) 25
. . . . . . . . . . . . . . . . . . . . . . . .
Derivative Control (Rate Control) 26
. . . . . . . . . . . . . . . . . . . . . . .
Deadband 27
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PID Band 27
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Positioning with the Linear Positioning Module 31. . . . . . . . .
How the Module Fits in a Positioning System 31. . . . . . . . . . . . . . . .
How the Module Interacts with a PLC 32
. . . . . . . . . . . . . . . . . . . . . .
Read Operations 32
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Write Operations 32
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Axis Movement 32
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Commanding
Motion 34. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setpoints 34
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jogging 35
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motion Blocks 35
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Table of Contents

Table of Contentsii
Hardware Description 41. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Indicators 41. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring Arm Terminals 42
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transducer Interface 43
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Determining
the Optimum Number of Circulations 43. . . . . . . . . . . . .
Discrete
Inputs 45. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto/Manual
Input 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware
Start Input 46. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware
Stop Input 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jog Forward Input 47
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jog Reverse Input 47
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Purpose Inputs 47
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog
Output Interface 47. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Discrete
Outputs 48. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OUTPUT 1 49
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OUTPUT 2 49
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supplies 49
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installing the Linear Positioning Module 51. . . . . . . . . . . . . .
Before You Begin 51. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Avoiding Backplane Power Supply Overload 51
. . . . . . . . . . . . . . .
Planning Module Location 51
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Electrostatic Discharge 52
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setting
Analog Output Switches 52. . . . . . . . . . . . . . . . . . . . . . . . . .
Keying 55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Inserting the Module 55
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Wiring
Guidelines 56. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Shielded Cables 56
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Using Twisted Wire Pairs 58
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting AC Power 58
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supplies 510
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting the Transducer Interface 510
. . . . . . . . . . . . . . . . . . . . . .
Power Supply 511
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Transducer Interface 512
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting the Discrete Inputs 512
. . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply 514
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto/Manual
Input 514. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware
Start Input 514. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hardware
Stop Input 514. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jog Forward Input 515
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Jog Reverse Input 516
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Purpose Inputs 516
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting
Multiple Modules 516. . . . . . . . . . . . . . . . . . . . . . . . . .

Table of Contents iii
Connecting the Analog Outputs 518. . . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply 519
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog
Output 519. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Connecting the Discrete Outputs 520
. . . . . . . . . . . . . . . . . . . . . . . . .
Power Supply 521
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OUTPUT 1 521
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
OUTPUT 2 521
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Interpreting ModuletoPLC Data (READS) 61. . . . . . . . . . . . .
PLC Communication Overview 61. . . . . . . . . . . . . . . . . . . . . . . . . .
Status Block 61
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Word Assignment 62
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module Configuration Word (word 1) 62
. . . . . . . . . . . . . . . . . . . .
Status Word 1 (words 2 and 6) 63
. . . . . . . . . . . . . . . . . . . . . . . .
Status Word 2 (words 3 and 7) 67
. . . . . . . . . . . . . . . . . . . . . . . .
Position/Error/Diagnostic Words 69
. . . . . . . . . . . . . . . . . . . . . . .
Active Motion Segment/Setpoint (words 10 and 11) 613
. . . . . . . . . .
Measured Velocity (words 20 and 21) 614
. . . . . . . . . . . . . . . . . . .
Desired Velocity (words 22 and 23) 614
. . . . . . . . . . . . . . . . . . . . .
Desired Acceleration (words 24 and 25) 615
. . . . . . . . . . . . . . . . . .
Desired Deceleration (words 26 and 27) 615
. . . . . . . . . . . . . . . . . .
Percent Analog Output (words 28 and 29) 616
. . . . . . . . . . . . . . . .
Maximum Velocity (words 30, 31 and 32, 33) 617
. . . . . . . . . . . . . .
Formatting Module Data (WRITES) 71. . . . . . . . . . . . . . . . . . .
Data Blocks Used in Write Operations 71. . . . . . . . . . . . . . . . . . . . .
Parameter Block (Required) 71
. . . . . . . . . . . . . . . . . . . . . . . . . .
Setpoint Block (Optional) 71
. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Block (Required) 71
. . . . . . . . . . . . . . . . . . . . . . . . . .
Parameter Block 71
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parameter Control Word (word 1) 73
. . . . . . . . . . . . . . . . . . . . . .
Analog Range (words 2 and 31) 75
. . . . . . . . . . . . . . . . . . . . . . .
Analog Calibration Constants (words 3, 4 and 32, 33) 76
. . . . . . . .
Transducer Calibration Constant (words 5, 6 and 34, 35) 77
. . . . . .
ZeroPosition
Of fset (words 7, 8 and 36, 37) 78. . . . . . . . . . . . . . .
Software Travel Limits (words 9, 10 and 38, 39) 79
. . . . . . . . . . . .
ZeroPosition and Software T
ravel Limit Examples 710. . . . . . . . . .
InPosition Band (words 11 and 40) 713
. . . . . . . . . . . . . . . . . . . . .
PID Band (words 12 and 41) 714
. . . . . . . . . . . . . . . . . . . . . . . . . .
Deadband (words 13 and 42) 715
. . . . . . . . . . . . . . . . . . . . . . . . .
Excess Following Error (words 14 and 43) 716
. . . . . . . . . . . . . . . .
Maximum PID Error (words 15 and 44) 716
. . . . . . . . . . . . . . . . . .
Integral Term Limit (words 16 and 45) 717
. . . . . . . . . . . . . . . . . . .
Proportional Gain (words 17 and 46) 718
. . . . . . . . . . . . . . . . . . . .
Gain Break Speed (words 18 and 47) 719
. . . . . . . . . . . . . . . . . . .

Table of Contentsiv
Gain Factor (words 19 and 48) 720. . . . . . . . . . . . . . . . . . . . . . . .
Integral Gain (words 20 and 49) 721
. . . . . . . . . . . . . . . . . . . . . . .
Derivative Gain (words 21 and 50) 722
. . . . . . . . . . . . . . . . . . . . . .
Feedforward Gain (words 22 and 51) 722
. . . . . . . . . . . . . . . . . . . .
Global Velocity (words 23 and 52) 723
. . . . . . . . . . . . . . . . . . . . . .
Global Acceleration/Deceleration (words 24, 25 and 53, 54) 724
. . . .
Velocity Smoothing (Jerk) Constant (words 26 and 55) 724
. . . . . . .
Jog Rate (Low and High) (words 27, 28 and 56, 57) 726
. . . . . . . . .
Reserved (words 29, 30 and 58, 59) 727
. . . . . . . . . . . . . . . . . . . .
Setpoint Block 727
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setpoint Block Control Word (word 1) 729
. . . . . . . . . . . . . . . . . . . .
Incremental/Absolute Word (word 2) 729
. . . . . . . . . . . . . . . . . . . .
Setpoint
Position 730. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local Velocity 731
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Local Acceleration/Deceleration 732
. . . . . . . . . . . . . . . . . . . . . . .
Command Block 732
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Axis Control Word 1 (words 1 and 8) 733
. . . . . . . . . . . . . . . . . . . .
Axis Control Word 2 (words 2 and 9) 738
. . . . . . . . . . . . . . . . . . . .
Setpoint 13 Words (words 3 to 7 and 10 to 14) 739
. . . . . . . . . . . . .
Initializing and Tuning the Axes 81. . . . . . . . . . . . . . . . . . . . .
Before You Begin 81. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Adjusting the Servo V
alve Nulls 82. . . . . . . . . . . . . . . . . . . . . . . . . .
Initializing the Parameter Block 82
. . . . . . . . . . . . . . . . . . . . . . . . . .
Verifying
Analog Output Polarity 87. . . . . . . . . . . . . . . . . . . . . . . . .
Verifying Transducer Calibration Constants 87
. . . . . . . . . . . . . . . . .
Axis Tuning 810
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Analog Calibration Constants 810
. . . . . . . . . . . . . . . . . . . . . . . . .
Feedforward
Gain 811. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PID Loop Gains 812
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Update the Application Program 813
. . . . . . . . . . . . . . . . . . . . . . .
Advanced Features 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motion Block 91. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motion Block Control Word 94
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Programmable
Input and Output 95. . . . . . . . . . . . . . . . . . . . . . . . .
Programmable
I/O Control W ord 95. . . . . . . . . . . . . . . . . . . . . . .
Default
I/O Configuration 98. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motion Segments 98
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motion Segment Control Words 98
. . . . . . . . . . . . . . . . . . . . . . . .
Desired
Position, Local V elocity, Local Acceleration
and Local Deceleration Words 911
. . . . . . . . . . . . . . . . . . . . . .
Trigger V
elocity/Position W ords 911. . . . . . . . . . . . . . . . . . . . . . . .
The Command Block and the Motion Block 911
. . . . . . . . . . . . . . . . . .
The Status Block and the Motion Block 911
. . . . . . . . . . . . . . . . . . . .

Table of Contents v
Using the Motion Block 912. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Sample Application Programs 101. . . . . . . . . . . . . . . . . . . . . .
Programming Objectives 101. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Block Transfer Sequencing 102
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
PLC5 Block Transfer Instructions 103
. . . . . . . . . . . . . . . . . . . . . . . .
Application Program #1 103
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Planning the Data Blocks for Application Program #1 105
. . . . . . . . .
Program Rungs for Application Program #1 108
. . . . . . . . . . . . . . .
Application Program #2 1011
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Planning the Data Blocks for Application Program #2 1012
. . . . . . . . .
Program Rungs for Application Program #2 1016
. . . . . . . . . . . . . . .
Troubleshooting 111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Fault Indicators 111. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Module
Fault Indicator 112. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Loop Active Indicators 112
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Indicator Troubleshooting Guide 112
. . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Feedback Faults 113
. . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting Flowchart 114
. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Flowchart Notes 117
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Glossary of Terms & Abbreviations A1. . . . . . . . . . . . . . . . . .
Status Block B1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parameter Block C1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Setpoint Block D1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Command Block E1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Motion Block F1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Hexadecimal Data Table Forms G1. . . . . . . . . . . . . . . . . . . . .

Table of Contentsvi
Data Formats H1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
BCD H1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
2's Complement Binary H1
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Bit Inversion Method H2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Subtraction Method H2
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Implied
Decimal H2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Position Format H3
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Double Word Position Format H4
. . . . . . . . . . . . . . . . . . . . . . . . . . .
Product Specifications I1. . . . . . . . . . . . . . . . . . . . . . . . . . .

Preface
P1
Preface
This manual explains how to install and configure the Linear Positioning
Module. It includes sample application programs to illustrate how to program a
PLCto work with the Linear Positioning Module.
This manual contains eleven chapters and nine appendices that address the
following topics:
Chapter Title Describes:
1 Introducing the Linear Positioning
Module
the functions and features of the Linear Positioning
Module
2 Positioning Concepts concepts and principles of closedloop servo
positioning
3 Positioning with the Linear
Positioning Module
using the Linear Positioning Module in a positioning
system
4 Hardware Description module hardware, module interfaces, and other
hardware items you need for a positioning system
5 Installing the Linear Positioning
Module
configuring the module's analog outputs and
installing the module in your system
6 Interpreting ModuletoPLC Data
(READS)
monitoring module operation from a logic controller
by reading and interpreting data that the module
transfers to the logic controller's data tables
7 Formatting Module Data
(WRITES)
formatting parameter, move description, and control
data for block transfers to the Linear Positioning
Module
8 Initializing and Tuning the Axes bringing the module online
9 Advanced Features using the motion block to perform blended moves;
using programmable input and output operations
10 Sample Application Programs two application programs, one using basic concepts
and the other using advanced features, to control
and monitor the module
11 Troubleshooting using the module's indicators and the status block
to diagnose and remedy module faults and errors
Appendix A Glossary common terms and abbreviations
Appendix B Status Block status block word assignments
Appendix C Parameter Block parameter block word assignments
Appendix D Setpoint Block setpoint block word assignments
Organization of the Manual

Preface
P2
Chapter Describes:Title
Appendix E Command Block command block word assignments
Appendix F Motion Block motion block word assignments
Appendix G Hexadecimal Data Table Form hexadecimal data worksheets
Appendix H Data Formats valid data formats
Appendix I Product Specifications 1771QB product specifications
Read this manual if you intend to install or use the Linear Positioning Module
(Cat. No. 1771-QB).
To use the module, you must be able to program and operate an Allen-Bradley
PLC. In particular you must be able to program block transfer instructions.
In this manual, we assume that you know how to do this. If you don’t, refer to
the User Manual for the PLC you’ll be programming.
Consult the Allen-Bradley Industrial Computer Division Publication Index
(SD 499) if you would like more information about your modules or PLCs. This
index lists all available publications for Allen-Bradley programmable controller
products.
The Hydraulics Configuration and Operation Option (Cat. No. 6190-HCO)
operates within the ControlView Core (Cat. No. 6190-CVC) environment to
provide full configuration and realtime monitoring for the Linear Positioning
Module. Both software packages are available from:
Allen-Bradley Company, Inc.
1201 South Second Street
Milwaukee, WI 53204
[phone]
Servo Analyzer is a software package that aids in tuning the axes by letting you
display an axis profile as you tune it. The resulting graphics may be plotted,
printed or saved to a file. The software is available from:
Computer Software Design
P.O. Box 962
Roseburg, OR 97470
[phone]
Audience
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