The following sections describe the entire process of creating an expression-based custom alarm. By following the examples, you create the expression (alarm calculation), assign the alarm to the output of the expression (alarm detection) and determine the message to the operator (alarm presentation).
You do not have to create your own expression to use custom alarms. You can assign a custom alarm to any Boolean parameter on a function block or module (except unit modules, phase classes, and phase logic modules).
The basic steps for adding an alarm are as follows: