Honeywell UDC2500 - Manual (Page 164)

Input Calibration
150 UDC2500 Universal Digital Controller Product Manual 4/07
Step Operation Press Result
or
until you change the input selection in the upper display back to the
proper selection. You will see:
Upper Display = Original Input Selection that matches your
type of sensor.
Lower Display
= INxTYP
4 Return to Normal
Operation
Lower
Display
Lower
Display
Lower
Display
to return to Normal operating mode.
The factory calibration will be restored. If the problem is not
corrected, contact the Honeywell Technical Assistance Center at 1-
800-423-9883 USA and Canada