Allen-Bradley ClutchBrake PLC-5 Series - Choice of Position Monitoring Devices; Control System Outputs; System Response Time

1–10 Overview of the Clutch/Brake Control System
Publication 65566.5.1 - October 1996
Purchased separately, you have a choice of dual position monitors:
•rotary cam limit switches
•resolvers
•combination of both
If using rotary cam limit switches, we recommend:
•a pair of Allen-Bradley Cat. No. 803-B94 or 803-P94
If using a resolver, we recommend one of these solutions:
•AMCI Series 1700 AMCI Resolver, and Absolute Resolver Input
Module that plugs into the 1771 I/O chassis
•NSD VRE–P062 Resolver and VE–2A Single Turn Converter
(decoder) that connects to a high-speed input module such as a
1771-IBD.
The clutch/brake control system is designed with three pairs of
outputs available for your application:
Use these Valve Outputs for these Functions Notes
clutch clutch/brake valves For clutch or clutch/brake valves
auxiliary auxiliary valves You can program these outputs in unison
with or in opposition to C/B valve outputs
microinch separate microinch drive Used in microinch mode only
The worst case time required for the clutch/brake control to respond
to a change of input depends on the sum of these response times:
(excluding scan time for auxiliary press functions that you can
compute from corresponding ladder logic)
Response Time Delay (ms)
1771ID16 input module 2
PLC5/x6 scan time for typical control logic 10
1771OD16 triac switching time 9
Total response time 21
The number of degrees that the shaft continues to rotate, beyond the
moment when the input changes, depends on the speed of rotation.
The greater the speed (strokes per minute), the further the shaft
rotates before a command from the control system is applied. The
response time of 21 ms is represented in degrees of shaft rotation that
increases as press speed increases (Figure 1.6).
Choice of Position
Monitoring Devices
Control System Outputs
System Response Time