Alarm properties can be used wherever variable tags can be used (except in alarm descriptions). For instance, you can provide the operator with a visual indication when the alarm CV110_ERROR is active. When it is active, CV110_ERROR.On will be TRUE; when it is inactive, CV110_ERROR.On will be FALSE. For example, CV110_ERROR.On could be entered as the fill color expression in a graphics object. When the conveyor becomes inoperative, the graphics object will change color.
To use an alarm property as a tag, it needs to be formatted as follows: Alarm tag (for example CV100_STOP) followed by a full stop (.) then the property (for example Category). The completed alarm property would then be CV100_STOP.Category.
Note: If you intend to use time-stamped digital or time-stamped analog alarm properties as variable tags, you will want to verify that they are configured correctly with the necessary data being pushed to the relevant variables via the Cicode function AlarmNotifyVarChange.
See Time-stamped Digital Alarms and Time-stamped Analog Alarms for more details on how these alarms operate.
Changes in Alarm Reference Syntax
In versions prior to 7.10 you could refer to an alarm's properties by dot notation ex. “Alarm1.On”. Such references could appear in both Cicode and on graphic pages and enabled you to see and control alarm states.
In CitectSCADA v7.20 an alarm’s properties carries not only value, as in 7.10, but also items similar to Tag Extensions items for example. “Alarm1.On.T”. The alarm reference syntax is now:
|Cluster||The optional cluster name.|
|Alarm||The alarm name.|
|AlarmProperty||The alarm property name. This part of the reference is not optional as it is for tags. There are different available properties for different categories of alarms as in 7.10.|
|Item||The optional Item name. If the item name is not specified, the value of the alarm property is referenced. Available items are the same as for tags: Value referenced by “V”, Value Timestamp “VT”, Quality “Q”, Quality Timestamp “QT” and overall Timestamp “T”.|