| 摘要 |
PURPOSE:To know the failure state of system clearly, by monitoring the changed amount of execution time of each step of process control sequence. CONSTITUTION:The output unit 4 outputting control information to controlled unit receives control information via the memory unit 2 and operator 3 from the input unit 1. In the memory unit 5, the execution time T1 of the preceding step corresponding to the execution of each step of sequence is stored in advance. The execution time changing amount detector 6 detects the absolute value ¦T1-T2¦ of the difference between the proceding execution time T1 and the present execution time T2 and adds it to the failure detector 7, which detects failure of sequence if the value exceeds a given value and makes alarm signal to the operator 3. |
