Electrical switches with current protection interfaced with a remote station and a portable local unit

摘要

An electrical switch (1) with overcurrent protection (3) communicates as a slave with a remote master station (39) by sending return messages to the remote master station (39) only in response to messages addressed to it. A portable unit (55) plugs into the electrical switch (1) and disables communications between the electrical switch (1) and the remote master station (39). The portable unit (55) then establishes communications with the electrical switch (1) by sending a global message to the electrical switch requesting the unique address at successive baud rates until a return message containing the electrical switches @ @ address is received. A communications module (25) in the electrical switch (1) transfers to a master mode in response to the global message in order to send the return message containing its unique address. It then reverts to the slave mode for response to subsequent messages from the portable unit containing the unique address. Either the remote master station (39) or the portable unit (55) can test the circuit breaker (1) by sending a message containing a digital test current to the circuit breaker (1).