Field device e.g. cerabar, operating method, involves producing change in respective operating condition of field device by change of terminal voltage lying close to input of communication supply line

摘要

The method involves connecting a field device (1) with a power supply unit (5) by a communication supply line (10). An entire electronics of the field device is supplied with a preset supply line by the power supply unit in one operating condition of the field device. A part of electronics of the field device is supplied with a preset preservation line by the power supply unit in another operating condition. A change in respective operating condition is produced by a change of terminal voltage lying close to an input of the communication supply line.