You can use the Signal Selector function block to select the maximum temperature input from four inputs and send it to a PID function block to control a process water chiller, as in the following figure:
Figure: Signal Selector function block application example (SEL_TYPE = max)
Or, you can use the block to calculate the average temperature of the four inputs, as in the following figure:
Figure: Signal Selector function block application example (SEL_TYPE = avg)
