Measurement sampling is enabled only when the value of the specified Item in the Item Trigger field is different from 0 (zero), with a frequency equal to that specified in the Group Period field.
Unlike the Continuous Time sampling, this sampling allows to limit the sampling in an unpredictable interval in the configuration phase, for example only when a plant engine is running

 

 

Note: The Invert field is available for the trigger item:
- if the Invert Trigger Item field is selected, sampling begins when the value of the item is zero.