You can extend the list of alarm properties by adding your own Associated Data or custom properties to an alarm you already have configured. These values can be static or dynamic. Static properties are excellent for filtering alarms. Dynamic properties can be driven by another Tag, or evaluated with an expression. Regardless of the type, the Associated Data property values will be attached to the alarm event, viewed in real-time, and recorded in the Alarm Journal system.
Alarm Property Bindings
Many alarm properties are bindable, which means they can be bound to other Tags in the system, expressions and even a UDT parameter. For example, you might bind the Enabled property to another Tag which represents whether or not your process is running, thereby disabling the alarm when production is stopped. Or, you might bind the setpoint of an alarm to a Tag that operators can manipulate, thereby letting the setpoint be changed at runtime.
This example shows how to bind an alarm property from the Tag Browser in Perspective. Simply double click on your Tag to open the Tag Editor, and following the steps below:
- Click on the Edit Configuring an Alarm on a Tag. icon next to 'configured alarms' binding to see your configured alarms. (If you don't have any alarms, create an alarm using the steps in the
- Select the alarm and the screen will refresh with all the alarm properties.
- From here, find the alarm property you want to add a binding to and click on the binding icon. The binding UI will slide in from the right.
- Select the binding type (No Binding, Tag, Expression, or UDT Parameter, if applicable). The image below shows an example of an Expression binding. Note that the expression can reference many useful values such as the Tag's value and other settings of the alarm. Enter your expression.
- Once you configured the binding to your liking, click on the 'Commit' at the bottom of the screen, or 'Back' if you decide to cancel.
- Click OK to save your alarm binding.
Alarms in Transaction Groups
Alarms can also be added to OPC items in Transaction Groups. This means alarms can be used without ever creating a Tag in Ignition. Simply edit an OPC item, and an Alarming section will appear in the Tag Editor window. From here, adding an alarm to the item is similar to adding an alarm to an Ignition Tag.