truss moving

In Wyg, make a linear axis, attach it to truss and patch it.
In Hog, patch a desk channel to the same address.
It's all in the Wyg manual...

i don't understand the second line , can you explain it in details please?

If you have patched your axis in Wyg for example in universe 1 / dmx address 1.
Add a desk channel in patch and patch it to universe 1 / dmx address 1
Use the desk channel to control the movement.
See section 4.5 (page 24) and section 7.1 (page 37) about patching
section 33.3 (page 372) about connecting to Wysiwyg
in Hog manual

I try something different but is little bit the same, so thank you very much:)