| 摘要 |
PURPOSE:To monitor each process when a collecting station, a master station is failed by connecting the 1st and 2nd collecting stations between a data transmission bus connected to plural control stations and a monitoring transmission bus connected to a process monitoring unit. CONSTITUTION:The data transmission bus B1 is connected to the control stations connected to plural processes and the 1st and 2nd collecting stations M1, M2 are connected to the bus B1. The monitoring transmission bus B2 connected to the process monitoring unit is connected to respective stations M1, M2. The stations M1, M2 are provided with failure detecting means 10 respectively and the means 10 are provided with master station absence detecting parts DT2 respectively. The outputs from power failure detecting parts PF1, PF2, reckless run detecting parts SA1, SA2 and on-line requesting parts OL1, OL2 in the means 10 are operated by AND circuits 11a, 11b respectively and the operated results are applied to other station failure detecting parts DT1a, 1b respectively. Consequently, each process can be always monitored. |
