Use PC-based control, key is industrial computer's reliability, who can tell me is there a example that a industrial computer can run 20000 hours without crash?
We use industrial PC's made by company TR Systemtechnik, Trossingen (Germany) Tel +49 7425 2280 (I hope to remember correctly - I have not my diary on ite) to run realtime DOS machine control. One of our applications since April 1998 runs round the clock, never being powered down. By now we had no crashes caused by hardware.
Oh yes, you'll have to qualify your question... No matter how reliably the hardware is, it can always be brought down by the OS or software...
Therefore perhaps you have to specify the operating system too. A regular embedded or industrial PC or even desktop can go for years without failure depending on use, OS, and environment.
