Overview
950-719-111-03, Revision 03
12
June 29, 2000
PCS-719 List 1A
Alarm Cutoff
The shelf backplane provides a wire-wrap pin for connection to an external alarm cutoff circuit.
Alarm Contacts
The COT shelf provides access to the PAU/PMU alarm relays by way of wire-wrap pins on the COT shelf
backplane. Both normally open (NO) and normally closed (NC) relay operation is supported.
shows the
configuration of the alarm relays.
Figure 3.
Alarm Relay Contacts from PAU/PMU to COT Shelf Backplane Wire-Wrap Field
Relay contacts are shown when alarm is not active.
NO
COM
NC
Critical
Audible
Critical
Visual
Major
Audible
Major
Visual
Minor
Audible
Minor
Visual
Shelf
I.D
Front Panel Alarm LEDs
Front Panel ACO LED
ACO (Yellow)
Alarms from COLU & MUX Units
(via Backplane Communication)
ACO Push Button
(PAU/PMU Front Panel)
External ACO Push Button
(Backplane Rear)
NO
COM
NC
NO
COM
NC
NO
COM
NC
NO
COM
NC
NO
COM
NC
NO
COM
NC
Critical (Red)
Major (Red)
Minor (Yellow)
X
X
X
X
X
X
X
PAU
or
PMU
External Alarm Relays
Relay Key:
= Normally Open (NO)
= Normally Closed (NC)