What is the manual/automatic switch for the DCS regulator?
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Instrument Tag Number, Purpose, Instrument Name, Signal Specification, P&ID Number, Data Table Number, Equipment/Pipe Number, Installation Location, Remarks: 06HIC-25819 – Vacuum pump flow; DCS display with adjustment function; – – DCS. 06HICY-25819 – Manual/automatic switching for the DCS regulator; ESD-DO – SIS signal from IC-231. 06HICX-25819 – Manual/automatic switching for the DCS regulator; DCS-DI – DCS. Question: 1. What is manual/automatic switching for the DCS regulator? What is its function? 2. Why are there two, ESD-DO and DCS-DI? What does it mean to have one output and one input? 3. What does it mean that the signal comes from IC-231? Thank you!
Automatic control loops are generally closed-loop systems: field measurement instruments convert process parameters into electrical signals which are sent to the DCS (DI). The DCS then generates a control signal (DO) through certain calculations, which is sent to the on-site control valves to adjust the relevant parameters. This process takes place automatically, that is, it is an automatic adjustment. Switching from automatic to manual mode requires manual adjustment of the output signal on the DCS in order to control the control valves on site.
A switch button between automatic and manual modes; DCS-DI is a feedback signal from the DCS side, and it generally shows on the DCS screen whether the current mode is manual or automatic. ESD-DO is the output model of the emergency shutdown system. The signal from IC-231 is likely a logic circuit of the emergency stop system. :)