Allowing Instruments to communicate natively via CIP Safety

[Hisma 2]

There seems to be a dearth of instruments that natively support CIP safety protocol.  I'm talking things like encoders, sensors, etc.  This means that if you are trying to achieve a high performance level or SIL rating, you need to come up with a more complex design.  

Has anyone here worked on some sort of protocol converter as a way to allow a device that talks some open standard, like RS-485 or modbus, and convert it on-the-fly to CIP safety, so that the device data can natively be brought into the safety task?  Seems like rockwell majorly dropped the ball on this.  It's something we're kicking around internally but still very preliminary, and I was wondering if anyone else has tried to go down this path and could give some tips.