Rockwell Automation 1771-QC , D17716.5.25 SER/B SERVO POS - Manual (Page 10)

Introducing the Servo Positioning Assembly
Chapter 2
2Ć4
feedback from your encoder. The 1771-ES expander is able to provide
this fast servo sample rate because the update is independent of the I/O
scan.
A drive-disable output provides a signal to disable the servo drive in
conditions such as loss-of-feedback or a hardware-stop signal. A
hardware-done output signals the completion of each single-step move.
Discrete hardware inputs include:
hardware stop
jog forward
jog reverse
home limit
feedrate enable
hardware start
The 1771-M3 controller sends axis status and diagnostic data to the data
table as directed by a block-transfer read instruction. Because
axis-command and status data is stored in the data table, axis motion
control can interact with other axes, discrete I/O, and report generation.
See the following table for a list of the many useful benefits you’ss derive
from an A-B servo positioning assembly.
Its Features