What is the control relationship in Mode C during DCS operation?
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I’m a beginner: In DCS operation, there are Mode A, Mode M, and Mode C. How is Mode C controlled, and what is the logical relationship between them? For example: what is the control relationship among the liquid level, flow meter, and control valve?
This post was last edited by jlshnlhj on 2021-7-31 23:41. Mode C refers to cascade control. Yokogawa also has a PRD main circuit single parameter.
Mode A: Automation Mode, self-control mode ； M mode: Manual Mode, manual operation mode ； Mode C: Cascade Mode, series mode.
C refers to Cascade cascade control or external control, where other variables are used to regulate this variable. For example, to stabilize the temperature in the middle section of the tower in air separation processes, the amount of liquid nitrogen taken out is adjusted. The value for the amount of liquid nitrogen taken out is set using the HIC handheld controller located next to C; a reference value is specified there. An output value is then generated based on the temperature in the middle section of the tower, and this output value, along with the reference value from the handheld controller, are processed through certain calculations (not necessarily just simple addition) to produce a set value that is applied to “C”. Adjustments are then made via valves
I’ve learned it! Thank you; cascade control is similar to proportional control