An Alarm Deadband helps to eliminate nuisance alarms caused by a tag’s value wandering above and below the alarm limit.
A Tag will enter an alarm condition only when the tag’s value exceeds the alarm limit. However, the point will NOT go OUT of alarm until the point’s value exceeds the deadband.
The Alarm Deadband is set during configuration of the tag, but can be changed in run-time VIEW while on-line from the point detail display if the user has access to the Security Level 127 configured for Tag Fields.
The Alarm Deadband used for the HH, H, L and LL alarms can also be changed by appending the .ADBP (Percent of Span) or .ADBV (Engineering Units) for to the tagname in the Point Info Dialog Box (point Browser). A common Deadband is used for the HH, H, L and LL alarms. There is a separate
The Alarm Deadband used for the Deviation Alarms can be changed using the .ADVDBV and .ADVBP Tag Fields.
To configure a Alarm Deadbands see 7.4Alarm Configuration.