Future Design MCT-MC 4.3, User Manual

Page: 118 / 186

MCT-MC
4.3
FDC MCT-MC - 118 - Offline Setup
Once the input has been verified to display the proper value according to the input reference signal, reconnect
the control sensor to the loop control and press the “Done” button. This will return to the main Calibration
screen.
10.5.2.2 RTD and Linear Input Calibration
When the loop input is configured with an RTD or linear input, pressing the “Perform Manual Calibration” button
on the main Calibration screen will begin the calibration procedure for the configured input type. The procedure
is a two step process and begins by calibrating the zero of the A to D converter.
To calibrate the input low coefficient, connect the resistance source (for RTD input), voltage source (for voltage input) or
milliamp source (for current input) to the input terminals of the loop control. Adjust the source signal to 100 ohms (for
RTD input), 0Vdc (for linear voltage input) or 0mA (for current input) and allow several seconds for the source signal to
stabilize. Record the current calibration coefficient value.
Press the “Calibrate” button to calibrate the input low coefficient. A dialog will be shown indicating the new coefficient
is being calculated. DO NOT alter the source signal during the process. Once complete, the dialog will close and the new
coefficient value will be shown.
If the new coefficient value is -1999 or 1999, the calibration failed. Check the source connections and insure
the proper signal is applied. Press the Calibrate button to repeat the process or press the coefficient
display/entry field and enter the previous coefficient value recorded to return the loop/limit back to its previous
state. To skip the input low coefficient calibration or to proceed to the next step after calibration has been
performed, press the “Next” button.