User guide

AN24 & AN28 Annunciators Instruction Manual
26
Relay Operation Overview
The following figure illustrates the operation of the relays.
A
CK
Pressed
ON
OFF
Relay 1
ON
OFF
Relay 2
ON
OFF
Relay 1
ON
OFF
Relay 2
NORMAL
FAIL-SAFE
A
larms
Cleared
Alarm
Occurance
Relay On: Relay is energized
Relay Off: Relay is de-energized.
Alarm Occurrence: A new alarm occurs when there is no previous
unacknowledged alarm.
ACK Pressed: The Acknowledge pushbutton is pressed,
acknowledging the alarm.
Alarms Cleared: All LED indicators are cleared of alarm state indication