After discussion with Fanuc, PCDK is an old protocol whose sustainability in time is no longer guaranteed.
Fanuc advised me to look into "Robot Interface" instead. So I'm implementing it in .NET. There are almost the same features as in PCDK : access to I/O, remote control of the robot, access to the registry, robot status...
Next month, I will release the same one for Yaskawa. And then, I will industrialize the library for Fanuc. So no release before the end of this year.
I have PCDK implemented in a lot of different products so I double confirmed this information with Fanuc support and the support agent said "I was able to get confirmation from my R&D department that PCDK will not be obsolete anytime soon." This is still hearsay but more recent hearsay lol