Emulation of an existing program

I have a large AB rslogic 5000 running program that I need to do some massive revisions to... I wanted to try to emulate the revisons before I go on line. I was reading about the 5000 emulation software and looking thru several posting and I not real sure that will do what I want? I was hoping to down load the existing prgram to a simulator/emulator to tweak & test the program before going on line.... Looking for some feed back on how others test programming. As always any help is greatly appreciated.

My 2c

I know of one instance where the emulator software does not behave the same as a real controller. Depending on your application, this may make the use of the emulator futile, and you could end up chasing your tail way too much to be comfortable. Of course, there may be other "incompatibilities" that I've not come across...

IMHO, the only way to test your application to give you 100% confidence is on the actual platform the target was designed for.