摘要 |
An information network which connects a centralized interactive unit for monitoring and controlling the operation of a plurality of plants and an individual interactive unit for monitoring and controlling a plant is connected to a control network which connects a control unit and the individual interactive unit by gateway means. The control unit multicasts a plant state quantity to the control network as a Tag if there is a significant change in the plant state quantity, and the centralized interactive unit and the individual interactive unit multicast a query about a plant state quantity to the control network and update a response from the control unit.
|