plc program simulator

Intro:
I'm new to plcs and I'm trying to learn and teach myself for several reasons. One, I'm frustrated over my ignorance on the subject and two, I would like to pursue and understand plcs and electronic control systems to a greater extent.

Question:
I apologize first if this question has already been asked 100 times. I don't need to transfer the program to a plc or do any actual system control. I want to know if there is a free or inexpensive program that I can use anytime to help train myself on plc programming. I've been working on the free program Trilogi which has helped me learn alot but I find myself wondering if there is a "fancier" or more advanced program available. Thank you in advance for your help.

Try the simulator above.

George

Have a look here also

http://www.thelearningpit.com/

You can also check out CoDeSys, you can download the demo version and use it for simulation. It has a trend-view of the variables and some other good features that will help you during simulation..
Besides, CoDeSys is considered to be very close to the IEC standard, so it would be helpful while you dont use any specific plc mahufacturer.