Rockwell Automation 1771-QA Stepper Positioning Assembly User Manual - Manual (Page 13)

2–3 Assembly and Installation
Publication 1771-UM002A–EN–P – May 2000
Stepper Translator and Power Supply
The stepper translator and power supply convert digital information
from the pulse output expander module into the proper voltage and
current for the precise control of a stepper motor. For compatibility
with the pulse output expander module, the translator must accept
low true logic. The programmed maximum pulse rate from the pulse
output expander module to the translator can be any value up to
20,000 pulses per second.
Stepper Motor
The stepper motor converts electrical pulses into mechanical
movements. The motor shaft rotates through a specific angular
rotation for each pulse. The movement is repeated precisely with
each pulse and the shaft rotates in fixed, repeatable increments.
When a threaded shaft is used to drive a linear slide, the velocity,
distance and direction of the slide can be precisely controlled.
The stepper motor, stepper translator and translator power supply
should be grounded to guard against electrical noise interference in
accordance with the manufacturer’s specifications and guidelines.
Improper grounding can result in unwanted extra pulses occurring at
the stepper translator and/or stepper motor.
Prior to installation, a pulse output expander module must be
configured to correctly interface with the corresponding stepper
translator.
Adjustments are made using six switch assemblies. The functions of
the switches are summarized in Table 2.A and described in
subsequent paragraphs.
Module Disassembly
The switch assemblies are located on the module printed circuit
board. They are accessed as follows:
1. Remove the four screws from the upper and lower edges of the
labeled cover.
2. Remove the printed circuit board from the covers and set it
solder-side down.
3. Locate the switch assemblies labeled S1 through S6 as shown in
Figure 2.2.
Pulse Output Expander
Module