Question about Controller in PLC

I have attached a line of controller. If see in the line it has write like: a(W15G1MF3) - b+ b(W14G1MF3) = b(W14G1MF3) why it did not write a = b .

If anyone please explain me it will be great help.

what brand PLC and model are you using?

Peter could you please explain ?

The first part looks like an integral part as I = I + P where I is your integral term and P is a proportional term (setpoint - feedback * Pgain). The P and I parts look like Dints and following the calculation the result is divided by 10000 and stored as an int (W15G1MF3). I don't fully understand what is shown after the integral term but I'm guessing that it is the derivative part and it looks like there is a switch to disable the D part.

I've never seen a language like that before.

Nick

Thanks Manglementer. Appreciates your reply. I did not understand the last part too what you have said it is derivative part. That is why i posted this question to get an answer
If any control expert here please explain a little it will be great help.