I am using multisim 12 on a win7 64bit PC.
Just to see what's possible with this software I created an easy regulation circuit (PID) but that doesnt matter.
I am not able to get the output of the last OP Amp above 2,5 Volts although it should. I tried the TL072, TL082 and different kinds of supply voltages. Whats wrong?
Or can it be any licensing issue as I am using the evaluation version?
As I couldn't attach an ms12 file I renamed it to ms11 --> Don't forget to change the filename back to ms12!
there is definitely no problem with your licensing. I have Power Pro Edition and also get 2.5V on Channel B.
The problem in your circuit is, that your ground, which you have put between V2 and V3 with each 18V makes problems (short circuit?).
When you look at my modified file in the attachements you see, that you get almost -29V on Channel B.
So, i think, the problem is more caused by false wiring or/and false grounding.
If you want to build controllers this link may be helpful for you: