| 摘要 |
PROBLEM TO BE SOLVED: To prevent missing of transmission data and to utilize a channel effectively by providing a re-retransmission means that again sends retransmission data, in case that retransmission to a master station has failed, when the master station sends multiple address communication data to a plurality of slave stations. SOLUTION: A data transmission processing means 21 of a master station decides which of a reference burst signal, retransmission wait data, re- retransmission wait data, and new multiple address communication data is to be sent to a high-speed data channel. A transmittal confirmation processing means 22 sends a transmittal confirmation commands, corresponding to data sent by the data transmission processing means 21 to a low-speed control channel. No transmittal confirmation command is sent with respect to the reference burst signal. A re-transmission detection means 23 considers it to be the presence of a re-transmission request from a slave station, based on a reception error of a loopback signal, if the transmittal confirmation command sent by the transmittal confirmation processing means 22. A re-retransmission detection means 24 receives a re-retransmission request, sent through the low-speed control line from the slave station. |
