Instrument failure alarm enhancement

As per the default functionality, Administrators can configure the system to generate Instrument Failure alarms against analog and rate points when a polled value falls below or exceeds either an instrument's minimum or maximum measurable value, or an instrument's lower or upper raw operating limit, respectively. In the alarm message, the system normally displays the limit that the value is either falling below or exceeding. As an enhancement to this feature, Administrators can configure the alarm message to also display the last good polled value.

Until the system polls an acceptable value, the actual value (curval) of the analog point is set to the last good value, as seen in the Analog Summary entry for the point.