Just for future reference it is lower in cost to just get 1 XP6 and then add as many ESC2 and PCM4 modules as you need in the remote locations. If you only have a single cat run between RP6 locations you can just convert that to a network feed and you are good to go.

Note if you do not have IP available where you are installing the xp6 you can set all of the RTI stuff to discrete IP addresses and just use a network switch to connect all of your expansion modules, you don't need an internet connection or even a router to do this, it works rock solid.