However I seem to recall that I had to set the PC IP address and the LS9 IP address.
I usually set them to:
Unless it's running on a wireless network, then the router is usually 192.168.0.1 and the other bits get nudged up one address.
Then you have to go into the yamaha network midi driver and search for the LS9.
Once the network midi driver has found the LS9 you can give it an name (default has it as "UNIT1" or something) and either set or apply the settings.
Once you've found and selected the LS9 in the network midi driver, you then fire up the studio manager and go into the settings menus (I use a mac now and it's called preferences, however It could properties or settings on a PC) and you're looking for "Midi Settings". Once there, select whatever the LS9 is (in my case it's called UNIT1) and hit apply.
Now quit out of settings, and load up the LS9 in the main Studio Manager window!
You only have to do it once per desk, however remember that if you have to change the settings on the desk (i.e IP address) you'll have to go through the process again.
Hope that helps. If not, phone Yamaha. They'll be more than happy to talk you through it and troubleshoot...or at least they were when I last ran into difficulties!
www.manninmusic.com Music Teacher, Isle of Man