Expression Builder

Another placeholder mechanism is enabled for the type variable property values: using an expression to define the value for a property. Expressions can be built using simple mathematical operators and functions. You can also insert substitutions into expressions.

You could also launch expression editor from the property value cell to build the expression.

For example, if you were defining a Pump type and create a variable called RPM, you could create a substitution for High Limit called “RPM_HighLimit” to define alarm limit values for this variable, and you could use an expression like Alarm Hi – “{RPM_HighLimit – 20}”. The substitution value can be set at an instance level and automatically the alarm limits are adjusted based on the High Limit.