| 摘要 |
A storage unit stores a first reference value of an input/output electric signal into/from control unit and a second reference value of an input/output electric signal into/from a monitoring unit. If the amount of deviation between the input/output electric signal into/from the control unit and the first reference value exceeds a threshold value, a first caution signal output unit detects degradation of the control unit and outputs a caution signal. If the amount of deviation between the input/output electric signal into/from the monitoring unit and the second reference value exceeds a threshold value, a second caution signal output unit detects degradation of the monitoring unit and outputs a caution signal. The first and second reference values are acquired and stored in the storage unit in a period between completion of production of the control unit and the monitoring unit and start of the operation thereof. |
