Basic ladder logic?

Try LogixPro from http://www.thelearningpit.com/ . You want to download the complete trial, including the student resources. It's the 12MB one.

Fire up the program and go to Help > Student Exercises. I just ran through the first few lessons, and they seem to be written pretty well.

Many PLC manufacturers include some kind of simulator with their programming software too. The problem is that you buy the PLC hardware, and then they get another $200 out of you for the software. Have you checked the software you have for any PLCs you are already using?

As an alternative, I've been using MC206 controllers from http://www.triomotion.com/. It's a motion controller with integrated PLC, CANbus, USB interface, and a dll if you want to write your own PC based user interface. It's multithreaded, too (up to 8 simultaneous running processes). At $1300, it's not always the best choice, but very versatile when you can use it.

Their MotionPerfect programming software is a free download and includes a simulator. The programming is VBish.

HTH

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George Radcliffe

Ah, VBish.. sounds right up my alley. Thanks fo rthe info George...

Love the avatar BTW..

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Sean Dotson, PE
RND Automation & Engineering
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Other replies below are good, also check out the pico controler from allen bradley the sofware is free and it has a built in simulator as well. Its functionality is limited however. Also check out PneusimPRO (Norgren) for pneumatics and electical control circuits they have a free download with a pneumatic/electric simulator but does not include PLC I dont think. Festo also offers something similiar. If you cant find them on the web let me know I will email or mail you some on CD.