MULTIPLEX COMMUNICATION EQUIPMENT

PURPOSE:To improve the control reliability of a multiple communication equipment by making this equipment join the communication when the control unit that could not output a connection answer signal within a prescribed time outputs a multiplex communication start signal and then a control signal is received from another control unit. CONSTITUTION:When the connection confirming signal is transmitted to a multiplex communication line 9, this signal is received by a body system control unit 4, a 4WS control unit 3, and a slip control unit 2 which are connected to the line 9. Then these units out put the received connection confirming signal to the line 9 respectively as soon as the start of a controller is complete. If a unit 1 receives an answer signal within a prescribed time after the unit 1 transmitted the confirming signal, the unit 1 decides that the units 4, 3 and 2 are connected to the line 9. If any control unit could not receive the confirming signal from the unit 1 nor output an answer signal within a prescribed time, a fact that the units 4, 3 and 2 are not connected to the line 9 is decided and the multiplex communication is started between the control unit and the unit 1.