MESSAGE RELAY PROCESSING UNIT

PURPOSE:To detect the title unit to be in an endless loop relay state due to any cause and to cope with it by providing a reception processing section, a relay monitor section and a transmission processing section to the unit. CONSTITUTION:A reception processing section 13 receives a message from a relay line 14 and gives a message having a destination other than a prescribed own destination in its destination information to a relay monitor section 11. Moreover, the relay monitor section 11 increments a count by one when the count of the received message is smaller than a monitor value to give the message to a transmission processing section 12 and starts a prescribed error processing when the count is not less than the monitor value. Then the transmission processing section 12 specifies a prescribed relay line 14 from the destination information of the received message and sends it to the relay line 14 deciding the message. Thus, the unit detects itself to be in an endless loop relay due to any cause and can cope with it.