| 摘要 |
PROBLEM TO BE SOLVED: To provide a communication system for connecting a plurality of slave stations using the serial interface of a master station. SOLUTION: Transmission line of the serial port of a master station 21 having a plurality of extension connectors is connected with the transmission terminal of the extension connector through a transmission circuit 33-36, respectively, and the reception line of the serial port of master station is connected with the reception terminal of the extension connector through a reception circuit 42-45, respectively. Each reception circuit comprises a master station of wired OR connection, and a slave station having a reception terminal and a transmission terminal connectable with the transmission/reception terminal of the extension connector. The communication system comprises a first communication control means for transmitting/receiving 2-byte data as one packet between the master station and the slave station, specifying the device ID, address and read/write at the first byte, and transmitting data at the second byte, and a second communication control means performing read or write processing if the slave station makes a decision that the device ID at the first byte matches its ID. COPYRIGHT: (C)2006,JPO&NCIPI
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