IWS_Training_Guide_v.. - FF-Automation

IWS Training Guide
Alarm Worksheets
Alarm Worksheets
You first need to specify the Tags used for Alarms in an Alarm Worksheet, entered in the Alarms folder in the
Tasks tab of the Workspace. The Alarm Group Number is 1-999 and is specified in the number in the Alarm
Worksheet, e.g. ALARMxxx.ALR where xxx=Alarm Group Number. The Alarm Group Number is used for
runtime filtering of Alarms by Group Number.
Alarms can be On-line only or On-line & Historical (i.e. Alarms will be saved to a disk database such as the WS
Proprietary Database or a Relational Database). The Alarm/Event Control Object is used to display either Online
Alarms or Historical Alarms.
Once an Alarm is Activated, it will be shown in the On-line Alarm/Event Control Object in the color specified in
the Alarm Worksheet (default is Red). At this point, the Alarm can either be Acknowledged (in which case it will
now be displayed in the Acknowledgment color – default is Green) or it can remain in the Activated state until it
returns to a Normalized value (in which case it will be displayed in the Normalization color – default is light
Blue). Once an On-line Alarm has been Acknowledged and Normalized, it will be removed from the On-Line
Alarm Display. Historical Alarms, however, will retain every Alarm state for the Tag.
In addition to the settings in the Alarm Worksheet, you can specify additional Tag Properties for
alarming. Tag Properties are accessed by selecting the Tag (e.g. from the Tag Datasheet View) and
clicking on the Tag Properties dialog Box.
The Tag Properties dialog box is where the Deadband Value is set, as well as the Deviation Setpoint and the
Deviation Deadband. This is the only dialog box where these Properties are set. All other Alarm Properties (e.g.
Limits) can be specified in the Alarm Worksheet.
A Deadband value around an Alarm limit is very useful when the Alarm is used for analog values (e.g. from a
sensor) that are susceptible to some level of noise or digitization variance. Having a Deadband Value
eliminates multiple Alarms triggering.
For example. if a Tag has a Hi Alarm limit of 80 and a Deadband Value of 5, WS will generate an Alarm when
the Tag value is >= 80. The Alarm is Normalized when the Tag value returns to a value < 75. If the Lo Alarm is
set to 20, the Alarm will Activate when the Tag value is 25.
21–2 InduSoft Web Studio