Thorsten,
Per the ViewSonic Manual you need to use 115200 baud rate for the COM port of the projector. Other than that, having a good connection and being absolutely positive you're using the proper COM device are the only things to check. Aside from the HEX codes of course. You can name them anything you'd like, just choose the proper display and the command you've saved from the dropdown menus, you much choose both, and then send the command. It should happen instantly if things are all properly connected and configured.
If you copied and pasted the codes, it might be worth typing them in just in-case there's a bug in the software. We'll be here if you need more help!
mUVe 3D Support