Disclosed is a method of operating a monitor device and an associated monitor device of an ostomy system including an ostomy appliance having an electrode assembly comprising a plurality of electrodes including a first electrode pair, the method comprising: obtaining one or more parameters including obtaining a first parameter of a first terminal pair connected to the first electrode pair of the electrode assembly; determining if one or more operability criteria are satisfied based on the one or more parameters including determining if the first parameter satisfies first operability criteria indicative of operability of the first electrode pair of the electrode assembly.