Echelon SmartServer 2.2 - Manual (Page 329)

330 Alarming
Alarming Overview
The SmartServer contains Alarm Generator and Alarm Notifier applications that you can use to
monitor and control the alarming of devices. The SmartServer also has an Alarm Notifier: Summary
Web page that you can use to view, acknowledge, and clear active alarms and an Alarm Notifier:
History Web page that you can use to view a log of active and cleared alarms reported by the Alarm
Notifiers. In addition, you can use an Alarm Monitor application to view alarm conditions on your
computer without connecting to the SmartServer Web page.

The Alarm Generator application can monitor up to 40 data points and trigger alarms by setting
the status of an input data point when a specified alarm conditions occur. You can add more than
40 Alarm Generators if you activate the v40 interface, which features a dynamic device interface,
on your SmartServer. .The Alarm Generator can optionally update SNVT_alarm or SNVT_alarm
_2 output data points, which can be connected to an Alarm Notifier or to another L
ON W ORKS
alarming device.

The Alarm Notifier application can monitor the status of selected data points, as well as
conditions sent via the SNVT_alarm and SNVT_alarm_2 output data points. When an alarm
occurs, the Alarm Notifier can handle the alarm condition by updating one or more data points,
sending an e-mail notification, and saving the alarm to a log file. A single Alarm Notifier can be
configured to monitor multiple data points.

The Alarm Notifier: Summary Web page lists all active alarms. It includes an option to
acknowledge an alarm so that the Alarm Notifier stops reporting the alarm condition, and an
option for clearing the alarm once the alarm condition has been fixed.

The Alarm Notifier: History Web page lists all the active and cleared alarms reported by selected
Alarm Notifiers for a given period of time. It lets you filter alarms based on the functional block,
data point, or time of alarm.
Using the Alarm Generator Application
The Alarm Generator application triggers alarms based on data point values. When you create an
Alarm Generator, you specify an input point and a compare point. The compare point can be another
data point or a constant value. When the input point or compare point are updated, the Alarm
Generator compares the values of both using a binary or analog function, whichever you select.
With the binary function, the Alarm Generator evaluates whether the input point is less than, less than
or equal, greater than, greater than or equal, equal, or not equal to the compare point based on the
logical function you select. If the result of the comparison is true, the Alarm Generator triggers an
alarm and updates the status of the input point to an alarm condition (AL_ALM_CONDITION). For
example, if you select Greater Than and the value of the input point is greater than the compare point
value, the Alarm Generator will trigger an alarm when either point is updated.
With the analog function, the Alarm Generator evaluates how far the input point is above or below the
compare point. If the difference exceeds one of four offset limits that you define, the Alarm Generator
triggers an alarm and updates the status of the input point to an alarm condition when either point is
updated. After an alarm has been generated based on an offset limit, the value of the input point must
return to the hysteresis level that you define for that offset limit before the alarm clears and another
alarm can be generated based on the offset limit. This means that the Alarm Generator will not trigger
additional alarms in between the time that the input point reaches an alarm condition and returns to a
normal condition.
The binary and analog comparison functions both have a throttle that you can specify to prevent the
Alarm Generator from triggering multiple alarms each time the input point reaches an alarm condition.
The Alarm Generator also has SNVT_alarm and SNVT_alarm_2 output data points. The status of
these output data points are updated to an alarm condition each time the Alarm Generator state changes