"Note, the HEQ5 and EQ6 Synscan mounts are plug and play ready for autoguiding with SBIG imaging cameras and autoguiders using the standard cable supplied with the SBIG product." -
http://www.skywatchertelescope.net/s...14&class2=1406
So it sounds like a technical issue compared to an incompatibility. I believe the EQ6 uses the LX200 command set.