Rockwell Automation 1771-SF1 SERVO INT MOD - Manual (Page 5)

Chapter
2
2Ć1
Component Interfacing, Module Preparation, and
Installation
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, 90 o 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.
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.)
General
Component Interfacing
Encoder
Differential Line Drivers
Servo Drive Package