| 摘要 |
PURPOSE:To report occurrence of abnormality of a CPU and to remove a failed controlling device from operation by connecting 1 circuit of every input group unit as a circuit to be tested, and examining whether connecting action of the system in normal or not by periodical switching. CONSTITUTION:Exchange controlling devices SPU11-13 connected to signal lines 101-103 are connected to the central processing unit CPU3 of an exchanging system through a channel network 2. One circuit in the circuit group contained in SPU11-13 is connected to test dial-tone devices 51, 52 respectively through a switching device 10. The devices 51, 52 make automatically calling, connection information and a series of predetermined test calling at a fixed perion according to time information from a clocking device, and checked whether reply is sent from devices 11-13 responding to individual action. When the devices 51, 52 can not obtain expected reply, a trouble signal is applied to a trouble monitoring device 6, and the number of devices 11-13 is reported from the device 6 to the CPU3. The device 11-13 of that number is removed from operating state. |
