Memory rewrite history recording device

摘要

The system stores the control program and / or control numerical value of the control device, is externally rewritable, and has a non-volatile memory. The system includes an inspector that inspects the stored data in the memory and determines whether the memory is normal or abnormal. The system includes a history recorder that records the history of external rewriting. The memory has an area for storing the adjustment value SUM-ADJ which is rewritten so as to prevent the inspection device from determining the abnormality. The memory has an area for storing the switch value INT-E / D that sets the validity or invalidity of the inspection by the inspection device. The history contains both adjustment values and switch values. A memory rewriting history recording device capable of efficiently discovering a rewriting action is provided.