Try these guys. I've followed their simulation product for years but have only used demo versions. Looks quite good to me. Its a Canadian Company called SSTech.
Try RSLogix Emulate 5, if used in conjunction with RSLINX you can run emulator,programming software and SCADA apps all on the same machine. You cannot however make online edits to the software, you have to edit offline, save and then reload the emulator. You should be able to find details at http://www.ra.rockwell.com
There is someone selling a full up PICS system on eBay. It looks like it includes both the PICS software and a Profibus DP interface module. I think you can just buy the Allen-Bradley Module and use the PICS software. Price is a lot better than buying new.
> Looking for software which will allow me to simulate AB PLC5 plc's