PURPOSE: To realize accurate network management by making the return of a reception confirming signal coincident with a substantial normal connection state of a communication node in a multiplex communication system returning the reception confirming signal when a signal is received.
CONSTITUTION: The system is provided with plural communication nodes 12 composed of a multiplex module 18 having a transfer section 14 and a reception buffer 16 accumulating a reception signal and of a control section 20 reading a reception signal stored in the reception buffer 16 and controlling a controlled system based on the reception signal. The plural communication nodes 12 are connected to a common transmission line 2 to implement multiplex communication between the communication nodes 12 and the multiplex module 18 returns a reception confirming signal when the reception signal is received. In such a multiplex communication system, only when the control section 20 is in the read enabling state of the reception signal accumulated in the reception buffer 16, the multiplex module 18 returns the reception confirming signal.
SONE AKIRA
NAKAJIMA TAKASHI