| 摘要 |
PURPOSE:To test a monitoring device with low equipment cost in a short time by providing a switching means which changeovers the connection extending to plural CPUs in an operation mode to the connection extending to one CPU in a test mode, in the monitoring device. CONSTITUTION:When a port switching instruction is executed on a CPU2 in the test mode, the instruction is transmitted to a command execution part 15. An input bus switching circuit 11 and an output bus switching circuit 12 are actuated through switching control lines 153, 154 to connect input bus cables 111, 141 each other and connect output bus cables 121, 142 each other. Consequently, bus cables 112, 131 and output bus cables 122, 132 are connected each other. Receiving an asynchronous report of switching end from the command execution part 15, a port circuit 14 sends the report to the CPU2 through the output bus cables 142, 121. Thereafter, all instructions applied from the CPU2 to the monitoring device 1 are executed in the command execution part 15 through the port circuit 14. |
