With the DELTAV system, where AI and AO are located in separate cabinets, how can a PID loop be established?
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Please, any expert who knows how can teach me. Currently, the liquid level signal AI is connected to the card in Control Cabinet 1 (CTRL01), while the valve signal AO is connected to the card in Control Cabinet 2 (CTRL02). Now, it is desired to use this valve to control the level of the liquid. How should a PID loop be constructed? How can the signals from one control cabinet be sent to another? I only know that Zhejiang University’s Zhongkong system has inter-station communication; I’m not very familiar with the DELTAV system, so I would appreciate some guidance from everyone.
Through the external parameter path field in the Input parameter section, there is a browse button to view the parameters of other controllers.
What version of the Deltab software do you have there?
Personally, I think you should still place AI and AO in the same controller; after all, using communication between controllers for control is not recommended.
It’s within a system; it’s just different controllers. As long as you select the external parameters, you can do it on one of those controllers!
Still regarding the fourth floor, I don’t know how to reply directly to your comments. I want to ask why it can’t be adjusted? Is it because the main cable isn’t long enough, or does controller 1 need to use this AI point? If it’s the latter, you can definitely use a one-input two-output safety barrier or a one-input two-output distributor (there should be one in the transition terminal cabinet).
Because adding 1 and having 2 output signals requires investment... Additionally, the wires need to be disconnected, which may affect production. Why must hardware be modified for something that can be solved through system communication between stations?
How can hardwiring be considered a shortcut? Any DCS system enables inter-station communication. Nowadays, large-scale chemical plants design CCR and FAR systems separately, with remote IOs and remote controllers being used more widely. Since I started working in process control, my supervisors and mentors have always emphasized, and it is also taken into account when the DCS manufacturer assigns IOs: the AI and AO components that are involved in control should be located in the same controller. Think about why this is the case.
Agree with you; change to hard wiring and IO allocation