Gurus, take a look at this control loop in your free time.
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As shown in the figure below: Please help describe this control loop. Thank you.
I’m not an expert; if what I say is incorrect, please feel free to correct me! FI211 is the flow display for Material A, FV211 is the flow control valve for Material A, and FIC211 is the regulating control for Material A ； FI212 is the flow display for Material B, FV212 is the flow control valve for Material B, and FIC212 is the regulating control for Material B ； FI211 is the main material; the FI212 material needs to be adjusted accordingly to FI211 at all times, following a certain ratio. FY211 represents this ratio value, and it should be set at the pins of the adjustment module. The set value for controlling FIC212 is FY211*FI211 ； (Generally, for FY211, this ratio has upper and lower limits.) ； FY210 is also a ratio value; it is usually directly displayed by the adjustment module ； FFA210 is a flow difference alarm, a low-level alarm; it should be an alarm based on the difference between the actual flow rate of FI212 and the flow rate FY211*FI211, which is the value calculated based on a certain ratio.
Isn’t there a ÷ symbol on FY211? Shouldn’t it be the quotient of two inputs? Why is there only one input field?
Take a look at the legend; it should refer to a ratio
This post was last edited by Hao Liang Zhi Le on 2022-4-8 at 12:25. This is a typical double-closed-loop ratio control system. The system displays both individual flow rates as well as the flow ratio. On FY211, there is a ÷ symbol there; it can be understood as a signal divided by a constant, which is equivalent to multiplying by that constant? It is generally not recommended to do this, as modifying the constant in division will lead to severe non-linearity; it is better to use a multiplier instead.
It’s exactly the part that puzzles me; like it