| 摘要 |
PROBLEM TO BE SOLVED: To report abnormality occurring to a control/supervisory terminal when a CPU for communication is normal even if the abnormality occurs at a CPU for control. SOLUTION: When any abnormality occurs at a CPU 4 for control, no normal response is returned from the CPU 4 for control within a prescribed time so that the abnormality can be sensed by a backup communication part 6, and the abnormality at the CPU 4 for control is reported from the backup communication part 6 to a CPU 5 for communication. When the abnormality notice response is returned from the CPU 5 for communication to the backup communication part 6, the abnormality at the CPU 4 for control is reported through the CPU 5 for communication to the control/ supervisory terminal 2. |
