How do DCS systems from various brands achieve interlocking programming of devices across different controllers?
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This post was last edited by Hardmen on 2010-9-5 08:56. For example, Device A is a field device connected to Controller #1, while Device B is a field device connected to Controller #2; Controllers #1 and #2 are linked via communication cables. The process requirements dictate that a interlock shutdown procedure should be implemented between Devices A and B. How do different brands of DCS systems achieve this? In versions of PCS7 prior to v7.0, dedicated communication program blocks within the controller were used to send and receive programs in order to call upon each other’s variables, which were then utilized locally for programming interlock sequences. ABB’s AC800F creates a global variable table, allowing controls connected via communication cables to recognize these variables; thus, these variables can be used directly within one’s own controller to program interlocks. Everyone, please also talk about how other brands’ DCS systems are implemented
They’re more or less the same; Allen-Bradley defines network variables and then implements network reading and writing； However, I’m not very convinced by network-based communication, as I’ve found in practical use that if the interlock signals are network variables, there is sometimes a delay in these signals ； We all use hard-point output followed by input at another station to achieve interlocking, ensuring its reliability ； Points that are not interlocked normally don’t matter.
For critical interlocking points, communication should be avoided as much as possible; the issue of communication delays is indeed significant in automatic control systems. For devices that are not that important, and for those that require sequential control based on process requirements but are located in two different stations, using programs can be a viable option – after all, it helps to reduce hardware costs, so it makes sense to consider such an approach.
Just drag the channel over and use it. In the engineering configuration, the names of all components are unique
Not all software can be configured in this way, right?