PH controller

For school we need to build a PH controller
the setpoint is variable and should be converted to a 0-100% scale
and then send to the CONT_C (pid controller).
now , the pid controller doesnt controll anything.. tryed allot and i cant get it working:/

now i ask you guys , can u please! check my program? and help me out?

Link : http://www.megaupload.com/?d=208I74X9

(programm was too big to upload it here )

http://rapidshare.com/files/430590797/MULTi11.11.zip
new link ! , the old one doesnt work for some reason:/

I guess you use Step7.

No Step7 available here, so I did not check your program.

But the standard failures are:

- Cont_C must be called from OB35 or another time-interrupt OB. Remember to update the sample time pin.

- Check that the controller is in auto mode. It is not if the MAN input is copied to the LMN output.

- The gain is set far to high, start with something like 0.5.

- Start with a integral time of f.x. 10s.

- Disable the derivate until you are ready for optimizing.

Kalle

Thanks man ! im trying it out right now=)
my MAN_ON value in the DB isnt initially on FALSE
how can i get it initially on FALSE? =(

Nevermind i thought wrong :/ , anyway it isnt on manuel.. if i give him a manuel value it also doesnt respond.. :/ $
it actually does nothing