I may be able to assist. My setup is based on Outback equipment. As you may know, this company is mainly composed of former Xantrex employees. These fine folks have very kindly provided a communication protocol on their web site (see link, below).
It is possible that the Xantrex SWCA protocol will be similar; especially considering that a third party company makes a monitor and control product (Winverter) that can talk to both Xantrex and Outback equipment.
As with the Outback equipment, you can connect a simple com program (like hyperterminal) to the SWCA (page 16 of the SWCA Users Guide). If you can do this, logging some of it to a file, you might find similarities to the Outback protocol.
Outback Protocol
Bon chance,
-Mark
markc@conotech.com