What logic do ENG and DEENG represent?
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I would like to ask about ENG and DEENG: what logic do they represent?
This design has some flaws that can confuse people, even though the intended meaning is correct. 1: Represents logical output of the program – 1; DEENG = solenoid valve is de-energized (ENG = energized), OPEN = main valve is open. A more appropriate design is: the inverted logical output equals 0, and 0 corresponds to DEENG.
That makes sense; if DEENG indicates a power loss, it would be better for the logical output to be 0, indicating a fault condition, and vice versa.
It turns on when power is lost and turns off when power is available; the front and back correspond to each other, which is also quite good
It’s clearer to consider the valve’s fault condition – FO or FC?
ENG is powered on while DEENG is powered off.
DE is the abbreviation for deenergize, meaning the solenoid valve loses power (interlock)
Why learn this? Design documents are just written randomly; I guess foreigners can’t understand them at all. The abbreviation for energize is ener; after de for power off, there should be a -, resulting in de-energized.
It’s not usually expressed this way, but it should be as follows: ENG: powered ON; DEENG: powered OFF