| 摘要 |
The present invention relates to a system comprising: a process control network ( 3 ) having process equipment ( 2 ) connected thereto for receiving, through the process control network, control commands and for transmitting messages. To enable a high-security-level system to be achieved, wherein the state of a process can be established from an external communication network, the process control network ( 3 ) is connected to an external communication network ( 5 ) via a one-way data transfer device ( 12 ). The external communication network has storage equipment ( 6 to 8, 13 ) connected thereto, configured to store at least some of the information contained in the messages to be transmitted from the process control network ( 3 ) to the external communication network ( 5 ). |
