![](/html/5a/5aaf/5aaf50e6318e80471cd86e88bd3704609a6ce3b6bc92cc6cb4ac661dc535e6e5/bg2.png)
Table of Contents
Introduction 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description 11. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
User Considerations 12
Component Interfacing, Module Preparation,
and Installation 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Component
Encoder 21
Differential Line Drivers 21
Servo Drive Package 21
Isolation 22
Wiring 22
Cable Recommendations 23
Shield Connection 23
Module Preparation 24
Module
Keying 27
Specifications 28
Interfacing
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
26. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Programming and Operation 31. . . . . . . . . . . . . . . . . . . . . . .
General 31. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Data Transfers 31
DAC Data (Servo Motor Speed) 31
Control Byte (Servo Motor Amplifier Inhibit) 33
Encoder Counter Values (Position Pulses) 34
Target Values (Position Interrupts) 34
Special Servo Lines on the Backplane 34
Marker 35
A > B 35
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
CCW/CW 35
Target Value Interrupt 35
Programming the Servo Control Functions 35
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . .
![](/html/5a/5aaf/5aaf50e6318e80471cd86e88bd3704609a6ce3b6bc92cc6cb4ac661dc535e6e5/bg3.png)
Introduction
Chapter
1
Description
User Program
EPROM
Programming
Unit
Plug-in EPROM
The Allen-Bradley Servo Interface Module (Cat. No. 1771-SF1) when
used with the Micro Controller (Cat. No. 1771-UC1) can control single
axis positioning systems such as found in machine tool applications.
When combined with a single motor variable speed drive package and a
full quadrature encoder, this microprocessor-controlled servo drive system
(Figure 1.1) can be programmed to cycle through precise speed and
position profiles.
Figure 1.1
MicroprocessorBased Servo Control System
Typical
User Application
1771- 1771UC1
Micro
Controller
SF1
Servo
Interface
Module
Amplifier Inhibit
Motor Current Inhibit
+
Velocity
Common
10V
-
Channels A & B, Channels
(Position Loop, 50KHz Max)
Single-Motor
Drive Package
Servo
Amplifier
A & B, Marker, Marker
Controlled Power
Return
(Velocity Loop)
Servo
Motor
Tach.
Drive
Shaft
Shaft
Encoder
Differential
Line Driver
10399
11
![](/html/5a/5aaf/5aaf50e6318e80471cd86e88bd3704609a6ce3b6bc92cc6cb4ac661dc535e6e5/bg4.png)
Chapter 1
Introduction
User Considerations
Operating features described in this manual must be totally programmed
in the user software (Z-80A opcodes) of the accompanying micro
controller. The servo interface module has the capability to perform as
described, provided that the software of the micro controller has been
completely developed. The user must assume full responsibility for
performing all systems engineering, programming, and software support
associated with the micro controller/servo interface module and intended
application.
12
![](/html/5a/5aaf/5aaf50e6318e80471cd86e88bd3704609a6ce3b6bc92cc6cb4ac661dc535e6e5/bg5.png)
Chapter
2
Component Interfacing, Module Preparation, and
Installation
General
Component Interfacing
Encoder
Differential Line Drivers
This chapter describes the necessary characteristics of user-provided
components, preparation and installation of the module and wiring
considerations. Refer to the Micro Controller Users Manual (Publication
No. 1771-6.5.5) for installation of the micro controller module.
The servo interface module must be compatible with other components of
the control system, including the differential line drivers, shaft encoder
and servo drive package containing the servo motor control amplifier.
Required characteristics of these components are stated below.
An encoder should have the following characteristics for monitoring the
rotational direction and position of a drive shaft.
Full quadrature, 90o out of phase (typical).
Maximum frequency to the servo interface module is 50 KHz for
Channels A, B, and marker.
Line drivers with the following characteristics can be used to transmit
encoder quadrature pulses to the servo interface module.
Servo Drive Package
Differential outputs for Channel A, Channel B, and marker.
TTL Source and Sink Currents = 15 mA max.
TTL Output Voltage = 2.4V (min.) high
= 0.6V (max.) low
Outputs available to the servo motor control amplifier must be compatible
with the following control voltage and current levels.
TTL output to inhibit the motor current.
TTL output to turn OFF the servo drive amplifier.
TTL Output Voltage = 2.4V (min.) high
= 0.6V (max.) low
TTL Sink Current = 12 mA (max.)
21
![](/html/5a/5aaf/5aaf50e6318e80471cd86e88bd3704609a6ce3b6bc92cc6cb4ac661dc535e6e5/bg6.png)
Chapter 2
Component Interfacing, Module
Preparation, and Installation
TTL Source Current = 7.9mA @ 2.4V
+10 to -10V DC analog output for forward or reverse proportional
motor speed control.
Isolation
Wiring
None of the terminals of the servo interface module are protected against
misapplication of AC, DC, or reverse DC.
CAUTION: Do not apply voltage or current sources to the
terminals of the servo interface module except those specified
for the terminals. Damage to the module may result.
If voltages are misapplied and damage is done to the terminal-side of the
module, the system-side including the data bus to the micro controller is
protected to 500V DC maximum isolation from the terminal side of the
module.
The line drivers and the servo amplifier of the motor drive package should
be wired to the field wiring arm connector of the servo interface module
as shown in Figure 2.1.
22