| 摘要 |
PURPOSE:To detect quickly the factor of a fault and recover the fault by setting an address storing the elements related to the fault and displaying the change of a signal related to the fault when a fault occurs to stop the operation of a machine. CONSTITUTION:An address setting circuit AM sets an address of a data memory which stores the state of each element of a sequence circuit, and a memory circuit TA form table A stores the address set by the circuit AM and the signal state of said address. While a signal change detecting circuit CSM detects the change of the signal state of the address stored in the circuit TA and stores a fact to a memory circuit TA for table B that the detected signl has finally changed to the actual signal state of the changed address. Then the address related to a fault is set to a circuit A when the fault arises, and therefore the signal state as well as the order of changed addresses stored in the table B are displayed to a display device. |
