Abstract: A control system includes one control unit connected to input/output units connected to an apparatus and another control unit capable of substituting for the one control unit. In the control system, the one control unit establishes connection to the input/output units. The control system includes a determination layer and a secure communication layer. The determination layer determines to establish connection between the other control unit and the input/output units when the connection between the one control unit and the input/output units is broken. The secure communication layer establishes connection between the other control unit and the input/output units in accordance with a result of the determination by the determination layer.

Abstract: A memory diagnosis apparatus to diagnose whether a fault occurs in a memory includes a diagnosis execution unit to divide the memory into a plurality of areas, select two or more base areas that are diagnostic targets from among the areas to carry out a memory diagnosis including a reading test and a writing test, and perform only the writing test in carrying out the memory diagnosis on a same base area for second or more times. The diagnosis execution unit is implemented by an arithmetic device that is a processing circuit that executes a memory diagnosis program stored in a storage device.

Abstract: A clock diagnostic apparatus repeatedly acquires clock values at constant intervals by software. A clock diagnostic unit (103) selects, from among the clock values which are acquired by the software, two clock values having a gap between acquisition timings, the gap being a predetermined time period which is sufficiently large compared to jitter which occurs at a time of acquiring a clock value by the software. The clock diagnostic unit (103) calculates a difference between the two clock values selected.

Abstract: A control system (1) includes one control unit (5D) connected to input/output units (4I, 4O) connected to an apparatus (2) and the other control unit (5W) capable of substituting for the one control unit (5D). In the control system (1), the one control unit (5D) establishes connection to the input/output units (4I, 4O). The control system (1) includes a determination layer (15W) and a secure communication layer (12W). The determination layer (15W) determines to establish connection between the other control unit (5W) and the input/output units (4I, 4O) when the connection between the one control unit (5D) and the input/output units (4I, 4O) is broken. The secure communication layer (12W) establishes connection between the other control unit (5W) and the input/output units (4I, 4O) in accordance with a result of the determination by the determination layer (15W).

Abstract: A memory diagnosis apparatus to diagnose whether a fault occurs in a memory includes a diagnosis execution unit to divide the memory into a plurality of areas, select two or more base areas that are diagnostic targets from among the areas to carry out a memory diagnosis including a reading test and a writing test, and perform only the writing test in carrying out the memory diagnosis on a same base area for second or more times. The diagnosis execution unit is implemented by an arithmetic device that is a processing circuit that executes a memory diagnosis program stored in a storage device.

Abstract: A clock diagnostic apparatus repeatedly acquires clock values at constant intervals by software. A clock diagnostic unit (103) selects, from among the clock values which are acquired by the software, two clock values having a gap between acquisition timings, the gap being a predetermined time period which is sufficiently large compared to jitter which occurs at a time of acquiring a clock value by the software. The clock diagnostic unit (103) calculates a difference between the two clock values selected.

Abstract: A RAM to be diagnosed is divided into n (n being an integer of 3 or greater) pieces of base regions. In an idle time of periodic processing performed in a system in which the RAM is incorporated, two base regions are selected from the divided base regions, and the selected two base regions are diagnosed using a diagnostic method capable of detecting a coupling fault. Thereafter, in an idle time of the periodic processing, operations to select an unselected pair of base regions and diagnose the selected pair are repeated, so as to diagnose all combinations of pairs.

Abstract: A RAM 200 to be diagnosed is divided into n (n being an integer of 3 or greater) pieces of base regions. In an idle time of periodic processing performed in a system in which the RAM 200 is incorporated, two base regions are selected from the divided base regions, and the selected two base regions are diagnosed using a diagnostic method capable of detecting a coupling fault. Thereafter, in an idle time of the periodic processing, operations to select an unselected pair of base regions and diagnose the selected pair are repeated, so as to diagnose all combinations of pairs.