MULTI-ADDRESS COMMUNICATION SYSTEM

摘要

PURPOSE:To decrease the rate of reduction in the throughput and to ensure the reliability of multiple address information by providing a means detecting it that the number of frames including the information representing abnormal reception of multi-address information frame of the same transmission order number from a master station is a predetermined number or over to the master station. CONSTITUTION:Let the transmission sequence number of a multi-address information frame BFj be Nsj, a value decided similarly to all slave stations be X and a value decided for each slave station be Yi, then a reply frame is sent when the following equation is established in each slave station; Yi=MOD (Nsj, X). If a reception frame preceding to the newest reception frame in the buffer is missing, a retransmission frame is generated and sent. A group having a high frequency of no reply being a cause to generate a signal requesting the retransmission request frequency and reply frame is separated from a signal requesting the retransmission and a signal requesting the reply frame at the master station. Thus, the reliability of a multi-address information message is ensured and the throughput is improved.