Junction box for use in the wiring system and the system of a plurality of proximity sensors and the PLC

摘要

PROBLEM TO BE SOLVED: To reduce wiring labor hour and wiring cost by dispensing with drawing of wiring from proximity sensors to a PLC, even when the number of proximity sensors with specific function is increased, and to maintain the wiring number to the PLC at a minimum wiring number.;SOLUTION: The system includes: a plurality of proximity sensors 2 each of which outputs detection signal and specific signal; the PLC 3 which respond to the signals from each proximity sensor 2; and a relay box 4 which relays and transmits the signals from each proximity sensor 2 to the PLC 3. The relay box 4 includes: a plurality of transmission wire connecting terminals 4a which individually connect a plurality of transmission wires 6 connected for each proximity sensor 2 to transmit the signals thereof; a bus wire connecting terminal 4b which connects a single bus wire 7 for network communication with the PLC 3; and an internal processing circuit 4c which performs processing to convert a plurality of signals applied to each transmission wire connecting terminal 4a from each proximity sensor 2 through the transmission line 6 into a signal form of network communication and to output the resulting signals to the single bus wire connecting terminal 4b.;COPYRIGHT: (C)2011,JPO&INPIT