| 摘要 |
PURPOSE:To reduce an influence of trouble upon the whole of a system by providing plural processors registered as the master and selecting another master processor at the time of the occurrence of trouble in one master processor so that a self-diagnosis signal can be transmitted. CONSTITUTION:A bus interface 11 is connected to a control signal line 10 and sets a connection condition for transmission and reception of a control signal, and a master register part 12 transmits and receives the control signal to and from one communication processor 10 at the time of request of master registration from another and registers one master in the system. Each of all processors 10 is provided with a master function processing part 15, and the processor 10 periodically transmits the self-diagnosis signal after being registered as the master by a prescribed contention selecting method. When receiving the diagnosis signal transmitted from another processor or a confirmation signal, the processor 10 registered as the master transmits a counterargument signal to avoid double master registration. Thus, one of the other processors is registered as the master when the processor registered as the master is disconnected by trouble. |
