LINE RELEASE PROCESSING SYSTEM FOR REMOTE SUPERVISORY AND CONTROLLING EQUIPMENT

PURPOSE:To eliminate the generation of an isolated slave station and to shorten an uncommunicable state by respectively laying master stations in both districts as a condition that the slave station which is switched to a relaying mode is caused to reset to a terminal mode. CONSTITUTION:If the master stations 12 and 13 lie in the districts A and B in lines 32 and 33 including a slave station 27 when the slave station 27 is switched to the relaying mode, it is reset to the terminal mode. If the master stations lie in one district, the slave station is maintained in the relaying mode as it is. With said processing, a continuous fault occurs in a point P and a point P4, and an isolation cancellation processing is executed by the switching of the slave stations 21-23 to the terminal mode and the switching of the slave stations 24 and 27, and then the slave stations 21 and 22 are immediately reset to the relaying mode by the fault restoration of the point P. Since the master stations 11 and 12 lie in both districts, the slave station 24 is reset to the terminal mode, and the two master stations 11 and 12 are prevented from lying in the slave stations 21 and 25. On the other hand, the slave station 27 is maintained to the relaying mode as it is, and 'no-master station' does not occur in the slave stations 28 and 29.