Rockwell Automation 1756-OF8I ControlLogix Eight-channel Isolated Analog I/O Modules - Manual (Page 149)

Rockwell Automation Publication 1756-UM540A-EN-P - May 2014 149
Calibrate the ControlLogix Isolated Analog I/O Modules Chapter 8
5. On the Calibration tab, click Start Calibration.
6. When the warning appears, click OK.
7. Select the channels to be calibrated and click Next.
The Attach Low Reference Voltage Signals dialog box appears, as shown
below. It indicates the channels are calibrated for a low reference and the
range of the calibration.