| 摘要 |
PURPOSE:To collect supervisory information and to speedily identify the fault part of a supervisory system. CONSTITUTION:Plural slave stations 2-1 to 2-n are connected to the transmission line 3 of a master station 1 in parallel, and they are connected to reception lines 4 in serial. Supervisory information of the salve stations 2-1 to 2-n are collected by a polling system. An information comparison part 8 compares request information from the master station 1 with return request information returned to the reception lines 4 at the termination of the transmission line 3. When comparison does not agree, fault information is transmitted to the master station 1. When request information addressed to the slave station on a lower side is received, a time out supervisory part 9 is started, and fault information is transmitted to the master station 1 even if response information from the slave station cannot be received within setting time. |
