Operation Manual 37107F
MFR 3 - Multi Function Relay
© Woodward
Page 45/165
Alarm Acknowledgement
By pressing the "ACK" push button, the output of the centralized alarm and the alarm messages on the LC dis-
play are acknowledged according to the following logic:
Horn:
After 2 minutes the horn is reset regardless of the acknowledgement of an alarm.
Interface:
All internal alarms are communicated via the interface.
NOTE
The control unit does not differentiate between short and long alarm acknowledgements when given
through the interface. As soon as the acknowledgement bit is enabled via the interface, a "Long ac-
knowledgement" will be performed. A "Short acknowledgement " via the interface is not possible.
Short acknowledgment (< 2.5 s)
Action
•
The "ACK" push-button is pressed for 0.5 s < t < 2.5 s
•
The terminal 36 is energized for 0.5 s < t < 2.5 s
Result
The "Alarm" LED changes from blinking to continually illuminated and the horn is silenced.
Acknowledgment via …
Operating mode
"ACK" button
terminal 36
interface input
AUTO possible possible
not
possible
MANUAL
possible
not possible
not possible
Table 4-8: Alarms - short acknowledgment
Long acknowledgment (>2.5 s)
Action
•
The "ACK" push-button is pressed for > 2.5 s
•
The terminal 36 is energized for t > 2.5 s
•
The acknowledge bit is enabled via the interface
Result
An alarm cannot be acknowledged if the fault condition still exists. If the fault condition is no longer
present:
•
The "Alarm" LED turns off
•
The F1, F2 and F3 alarm relays are reset
•
The display messages are acknowledged
Acknowledgment via …
Operating mode
"ACK" button
terminal 36
interface input
AUTO possible possible possible
MANUAL
possible
not possible
not possible
Table 4-9: Alarms - long acknowledgment
