PURPOSE: To resume a processing by oneself by permitting a diagnosis processor and a service processor to re-raise each other when one is inoperative even if one of the service processor and the diagnosis processor becomes inoperative due to the occurrence of trouble.

CONSTITUTION: The diagnosis processor 200 re-raises when the service processor 300 becomes inoperative and the service processor 300 re-raises when the diagnosis processor 200 becomes inoperative. Namely, the service processor 300 and the diagnosis processor 200 have the functions of mutual re-raising. Thus, re- raising which is conventionally executed by the manual operation when the service processor is inoperative can automatically be executed and an inoperative state is rapidly relieved.