| 摘要 |
<p>The display for a process control system can be generated by one of two different sources, but is controlled by only one of them. A process control system network provides a first source of display (namely information regarding the operation of the process control system), while a windowing system provides a second source (e.g. external computer systems). The windowing system controls the display by opening and maintaining windows, e.g. a window in which the control system network can display information. To allow the control system network to communicate information, a window is opened by the windowing system, and then the process control network is allowed to overwrite information into this newly opened window. Also, should the windowing system fail, control of the display is given to the control system network. <IMAGE></p> |
