COMMUNICATION SYSTEM

摘要

PURPOSE:To attain cyclic simultaneous multiple address transmission for data to plural local machines without increasing a communication cost and increasing traffic of each local machine efficiently. CONSTITUTION:A local machine 9 is provided with a transmission error detection means using an error check code to detect the presence of a transmission error as to transmission data from a host machine 1 and with a transmission error information transmission means sending transmission error information to the host machine through a ground line when the transmission error detection means detects a transmission error. The host machine 1 is provided with a transmission error information collection means collecting number of local machines unable to receive data normally based on the transmission error information from the local machine 9 and with a transmission time control means controlling the transmission time of data to the local machine based on number of the local machines collected by the transmission error information collection means.