| 摘要 |
PURPOSE:To ensure the proper transmission of data between a duplex control device and a single control device by delivering the transmission data to the control device of the remote side by a control means via an interface in a state where a protocol is converted. CONSTITUTION:The transmission of data is performed between control devices 1 and 1' and a control device 2 via a data converting device 3 while the device 2 is controlling a plant B. In this case, a control device 2' is kept under a waiting state and therefore no significant data is sent to system buses 1b and 1b' from a data converting device 3'. Thus data are never sent simultaneously to both buses 1b and 1b' from both devices 3 and 3'. At the same time, data are sent to the device 2' from devices 1 and 1' via the device 3'. However the device 2' does not fetch the data. Then the device 2' becomes active and the transmission of data is carried out between the device 2' and the devices 1 and 1' via the device 3' as soon as the device 2 has a fault and is set under a waiting state. |
