Logical expressions - those that return either TRUE (1) or FALSE (0) -can be used as triggers.
For example, you might need to log the expression in the above example only when an associated pump is running.
|
Trend Tag Name |
B1_TIC |
|
Expression |
B1_TIC_101_PV + B1_TIC_102_PV |
|
File Name |
[log]:B1_TIC |
|
Trigger |
B1_PUMP_101_CMD |
In this example, the trigger is the expression B1_PUMP_101_CMD (a digital variable tag). If the pump is ON, the result of the trigger is TRUE, and the value of the expression (B1_TIC_101_PV + B1_TIC_102_PV) is logged. If the pump is OFF, the result is FALSE, and logging ceases.
See Also