To eliminate a necessity of allocating identifiers to slave units 10 for identifying the slave units 10.
A monitor device 100 for monitoring the batteries 1 including a plurality of batteries 1 and a power supply line 3 electrically connecting these comprises: detection circuits 11 for detecting the voltage of a prescribed battery 1 among the batteries 1, and transmitting the resulting detected voltage of the batteries 1 and answering signals responding to a command to output signals through the power supply line 3 after a conversion to AC communication signals; an identification circuit 23 for receiving the answering signals transmitted from the detection circuits 11, then comparing transfer characteristics deduced from the answering signals so as to identify each detection circuit 11 according to comparison results of the transfer characteristics; and a control circuit 21 for receiving the resulting detected voltage of the batteries 1 from the detection circuits 11 identified by the identification circuit 23.
FUJITA TAKESHI
KINOSHITA TAKUYA
