Omega WI8XX-U - Manual (Page 47)

4.3.7.3 Alarms 1 & 2
Alarm 1 (or 2) Relay: to enable or disable (no alarm function) the alarms .
Alarm 1 (or 2) Low: editable box for the low alarm value.
Alarm 1 (or 2) High: editable box for the high alarm value.
Active: If Above, Alarm condition triggered when the process variable is greater
than the Alarm Hi Value (Low value ignored).
If Below, Alarm condition triggered when the process variable is less than the
Alarm Low Value (Hi value ignored).
If Hi/Low, Alarm condition triggered when the process variable is less than the
Alarm Low Value or above the Hi Value.
If Band, Alarm condition triggered when the process variable is above or below
the "band" set around the Setpoint. Band equals Hi Value (Low Value ignored).
A "band" is set around the Setpoint only in the "Deviation" Mode.
Normally: if Open, then the relay is "energized" only when an alarm condition
occurs.
If Closed, this is "Fail Safe" Mode. Relay is energized under "normal" conditions
and becomes de-energized during alarm or power failure.
Latch: if Latched, Alarm remains "latched" until reset.
If Unlatched, Alarm remains latched only as long as the alarm condition is true.
Absolute: if Absolute, this allows Alarms to function independently from their
respective Setpoints. If the process being monitored does not change often, then
"Absolute" Mode is recommended.
If Deviation, this allows changes to Setpoints to be made automatically to their
corresponding Alarms. Deviation Mode is typically the ideal mode if the process
temperature changes often. In Deviation Mode, set Alarm 1 a certain number of
degrees or counts away from Setpoints, this relation remains fixed even if
Setpoints are changed.
Alarm at Power On: If the alarm is enabled at Power On, the alarm will be
active right after reset for all the End Devices (given the conditions are met),
except the End Device designated in the "Input" menu of the Web Server.
If the alarm is disabled at Power On, the alarm will become enabled when the
process value enters the non alarm area. The alarm is not active while the
process value is approaching the Setpoints.
Errors indicating "lost" or "open" sensor condition can trigger the alarm if
the alarm is set for "active high" above 9000 degrees.
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