External compensation with flanking channel

A flanking channel of the same input group can be used for compensation, e. g. for channel 3, the channels 0, 1 and 2 can be selected as reference channels. The type of sensor for the reference channel can be selected in the parameters for the flanking channel. For example, a RTD sensor which is located next to the thermocouple terminal can be used as reference point for other channels.

The setting “Channel x” for the parameter “Compensation channel” should be selected. Refer to Channel configuration AI531 - Analog Input Module for possible settings.

In order to avoid error messages from unused analog input channels, it is useful to configure them as “unused”.