Hello Acquiris,
You can find information about RTIsShuttingDown in the following topic in the CVI online help:
Programmer Reference>>Creating And Downloading DLLs to Real-Time Targets>>Creating and Downloading Real-Time DLLs from LabWindows/CVI>>Using RTmain
There is no standalone help for the real-time module. The help is all incorporated into the CVI help. So, for example, if you look in the help under the "Creating And Downloading DLLs to Real-Time Targets" book, you should be able to find some help.
Luis