CoDeSys is multi-vendor, many different PLC manufacturers use the CoDeSys runtime and therefore the CoDeSys platform can be used to program them.
However, a lot of vendors use their own implementation of CoDeSys, so have their own software that is based on CoDeSys, but CoDeSys itself cannot be used to download to the PLC. Schneider’s SoMachine platform is a good example of this. IFM however use native CoDeSys to design the program, then a download tool to push it to the PLC.
CoDeSys 3.5 (and 2.3) has a powerful PLC simulator built in. In my opinion, it’s the best of any simulation system I’ve ever used. This is because it runs a 100% copy of the same kernal that runs in the PLC, nothing is different, even networks are available to be used.
I’ve used the simulated PLC for testing with real PLCs, using my laptop to push modbus messages out to real PLCs for sequence control and all sorts.
Other devices such as Parker’s AC inverters are also built on CoDeSys, allowing easy interaction with CoDeSys PLCs.
CoDeSys accepts EDS files and GSD files from other vendors such as Siemens too, so building projects that interact with other PLCs that are not programmable by CoDeSys is still easy.
All IEC languages are available, CoDeSys is fully IEC compliant.
Honestly, it is the best plc platform for its value, everything is cheap or free and very powerful. If I were Allen Bradley or Siemens, I’d be worried just how far the CoDeSys platform could penetrate the PLC industry over the next 10 years. There’s only a matter of time before people start wondering why a £100 PLC with a free license can do everything a £2000 PLC with a £1000 seat licence can do.
Go and try it out, CoDeSys is awesome. I’ve used it for many many years and am currently writing learning modules for it. I won’t share the link to them here and it’s a direct conflict of interest with this site and that’s not fair. But feel free to ask questions and I’ll give you an answer