Patent ID: 8035256

Claim:
A switching device for switching at least one current phase between a responsive current phase input and a responsive current phase of a power circuit of an electric motor, comprising: a first communication system interface for a first communication system, the switching device communicating with a remote control system over the first communication system; a second communication system interface for a second communication system, the second communication system being a master-slave bus; a selecting element that selects whether the switching device is a master device or a slave device in relation to the second communication system, depending on whether the first communication system interface is connected to the first communication system, whereby the selecting element has a function of a gateway between the first communication system and the second communication system: and a state checking unit that, when an on-site control device is detected, allows providing information received through the second communication system interface to the on-site control device, or accepts commands received from the on-site control device, wherein the state checking unit is adapted to allow providing the information or to accept the commands only after having detected a valid key.