Rockwell Automation 1771-PD PID MODULE (+DU) - Manual (Page 53)

Programming
Chapter 3
3Ć10
such as feedforward, scaling, lead/lag, and all the words in the loop
block must have a value. The value of unused expanded feature
words must be zero.
W01 B13 Calibration. Reset to 0 selects normal operation. Set to 1
only for calibrating the module. This bit is examined only at
power-up, and is used with W02 B17 and B16.