| 摘要 |
PROBLEM TO BE SOLVED: To suppress the decrease in throughput in communication between computers and to correctly execute status data communication by receiving main data from a 2nd channel to demodulate the received data and receiving status data from a 1st channel to demodulate the received data. SOLUTION: Packet data based on Ethernet specification are outputted from a computer 14 to a CPU 15, which separates a management information base(MIB), i.e., status data for managing a transmission line and a communication state, from the packet data. The status data are PSK-modulated by a 1st modulator 16 and the modulated data are sent to a 1st channel on a transmission line E. The remaining main data are QPSK-modulated by a 2nd modulator and the modulated data are sent to the transmission line E. A center device C receives the status data from the 1st up channel, demodulates the received data by a center modem 11, receives the main data from the 2nd up channel, and demodulates the received data by a center modem 12. The status data are decoded by a computer 10 and the main data are decoded by a computer 13. |
