| 摘要 |
PURPOSE:To execute effectively a diagnosis when communication is abnormal, by providing a monitor device and a monitor timer in the inside of each computer, and operating the monitor device, when a response message is not received within allowable time at the time of transmission. CONSTITUTION:Computers 1, 2 and 3 contain a transmitting device 4, a receiving device 5, a monitor device 6 and a monitor timer 7, respectively. When transmitting a message from the computer 1 to 2, the device 4 of the computer 1 sets the timer 7, and when there is no response within a prescribed time, the timer 7 becomes time-up and operates the device 6. The device 6 instructs the device 4 to transmit a patrol request message to the computer 3. As a result, the device 5 of the computer 3 executes a patrol request of the computer 2 to the device 6, and the device 4 transmits a patrol message to the computer 2. As a result, when the transmission has been executed normally, a fault can be limited to a line between the computer 1 and 2, and when the time is over, it can be diagnosed that a terminal of the computer 2 is abnormal. In this way, when communication is abnormal, the diagnosis can be executed effectively. |
