Rockwell Automation 1440-VAD02-01RA XM-123 Aeroderivative Module - Manual (Page 75)

Publication GMSI10-UM003D-EN-P - May 2010
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Determines whether the relay is failsafe or
non-failsafe.
Failsafe operation means that when in alarm, the
relay contacts are in their "normal," de-energized, or
"shelf-state" positions. In other words, normally
closed relays are closed in alarm, and normally open
relays are open in alarm. With failsafe operation, a
power failure equals an alarm.
The following are true of a relay in failsafe
operation:
•
The relay is energized when power is applied to
the module.
•
The relay in a nonalarmed condition has power
applied to the coil.
•
In alarm condition, power is removed from the
relay coil, causing the relay to change state.
For non-failsafe operation, the following are true:
•
Under nonalarm conditions, the relay closes the
circuit between the common and the N.C.
(normally closed) terminals.
•
Under alarm conditions, the relay changes state to
close the circuit between the common and the
N.O. (normally open) terminals.
For failsafe operation, the following are true:
•
Under nonalarm (with power applied to the unit)
conditions, the relay closes the circuit between the
common and the N.O. terminals.
•
Under alarm or loss-of-power conditions, the relay
changes state to close the circuit between the
common and the N.C. terminals.
Relay Parameters
Parameter Name Description Options/Comments
XM Configuration
Utility EDS File
Failsafe Relay Failsafe
Option
XM Configuration
Utility EDS File
Check means
failsafe Failsafe
Clear means
non-failsafe Nonfailsafe