The Input Selector function block can be used to report average zone temperature with maximum and minimum temperature conditions on a group of temperature transmitters.
To use the Input Selector function block in this way, create a module of three (3) Input Selector function blocks and the analog inputs from the temperature transmitters (for this example, use four (4) analog inputs).
The first Input Selector function block continuously monitors average temperature and validates data only if three or more field inputs are present. The second and third Input Selector function blocks monitor the maximum and minimum temperatures in the zone and which indicators are responsible for reporting those temperatures.
This example provides a simple way of handling input data from a continuous process furnace for subsequent reporting and burner/blower management.