COMMUNICATION RECOVERY PROCESSING SYSTEM FOR REMOTE SUPERVISORY AND CONTROLLING EQUIPMENT

PURPOSE:To quickly recover a communication function which reducing the wasteful data refresh by performing the recovery processing of the data refresh only when an incommunicable state is continued over prescribed time. CONSTITUTION:A communication feasible/infeasible detecting part 31 issues a request to perform the start-up of a start-up storage part 32 i.e., the data refresh to a master station 1 with a start-up signal due to the recovery of incommunicability. Such start-up is not performed until the incommunicable state continues over the time limit of a timer. Therefore, no data refresh is performed when the incommunicable state is continued in a short time, thereby, communication leakage can be prevented from occurring at the incommunicable state in a short time by performing re-transmission that is an ordinary procedure. Also, recovery from the incommunicable state over the time limit of the timer is performed by immediately starting up the device from change to a recovery state with a change detection circuit 27, then, quickly performing the data refresh.