A little late to the party, but we used the ASCII text datalinq to grab the data from the radar guns. The data can come into the XPression either via direct serial connection or from a serial to ethernet conversion. Depending on the model of radar gun, I sometimes had to script around the data received to make sure we weren't getting catcher throwbacks or bat swings. Some of this can be minimized by proper gun location as well.
#XPression