Ben -
Here is a good KB that describes where to go for me information of multichassis synchronization (
KB 2WF8F22L).
Here's a quick overview:
You will need a 6652/3 in slot 2 of the master chassis and a 665x in slot 2 of the slave chassis. The master 6652/3 will generate all of your timing signals to both the master and slave chassis. The slave 665x routes all the signals to the appropriate line on the PXI backplane.
Your two chassis may be connected by MXI-3/4 or they might both have a controller in them. In the case where you are using MXI, everything will show up in MAX like they already do and that is how you will address them. The 665x boards use a different drvier, called NI-SYNC which you will need to download as well.
I've attached some sample code which will synchronize boards in two chassis using DAQmx. Hopefully you'll find this a good place to start on the LabVIEW side.
-Jack