Nice freeware effort. I've made my living doing real PLCs (mostly Allen-Bradley) for years. They eventually came out with a soft PLC to run on NT. Their biggest impediment was the flakiness of Windows and the fact that it used preemptive multitasking. Kept it from being 100% deterministic. I think they may have written their own real-time kernel, but I don't remember for sure. Of course they sell their stuff to heavy industry where failure isn't an option.Originally Posted by ynneb
One thing I would recommend if anyone is going to play with something like this and run real machinery is a hard-wired kill switch or e-stop that will remove power from the motor drives WITHOUT going through the logic. If the PC should hang you DON'T want the hardware running away.
His page has plans for the I/O board shown. I wonder if he supports other I/O boards, like the OPTO 22 stuff?