Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 7)

Chapter
1
Publication 1771-UM002A–EN–P – May 2000
Introduction
The Stepper Motor Positioning Assembly (cat. no. 1771-QA) allows
programmable control of stepper motors by Allen-Bradley
programmable controllers. Data and commands set to the stepper
positioning assembly are converted to a pulse output for a
user-supplied stepper motor translator which in turn provides the
proper voltage and current to the stepper motor to produce the
desired motion. The stepper motor positioning assembly consists of:
•
1 Stepper Controller Module (cat. no. 1771-M1)
•
1 Pulse Output Expander Module (cat. no. 1771-OJ)
•
1 Field Wiring Arm (cat. no. 1771-WB)
One stepper controller module can control up to three pulse output
expander modules. The system can be expanded modularly from
one to three axes per I/O chassis by placing from one to three output
expander modules in the chassis (Figure 1.1). The pulse output
expander modules can be located in any slot except the left-most slot
and in any order in the I/O chassis.
Figure 1.1
Typical System Block Diagram
1771 I/O Rack
PC
Bi–Directional
1771–M1
Backplane
1771–OJ 1771–OJ 1771–OJ
Move
Move
Move
Status
Axis #1
Axis #2
Axis #3
Translator
Translator
Translator
Axis #3
Stepper
Axis #2
Stepper
Axis #1
Stepper
10509
Processor
Block Transfer
Stepper
Controller
Module
Communications
Pulse
Output
Expander
#3
Pulse
Output
Expander
#2
Pulse
Expander
#1
Output
Data
Axis #1
Data
Axis #2
Data
Axis #3
Data
Motor
Motor
Motor
•
Description