Hi Carlos,
The SBIG camera/s are OK in themselves.
When you may need the relay, either mechanical or preferably optical, is for the standard Losmandy mounts.
That is the G8, G11 or GM mounts with stepper motors.
The original problem was with the standard Losmandy stepper motor controller which used a ´floating earth´.
This should not exist with the FS2 controller.
However I used an FS2 with a big Losmandy for years and had to be very careful about getting ¨return earth loops¨.
I usually had to use a separate 12 volt power supply to power the FS2 and say a digital encoder box or other equipment on the camera or mount. This also involved not connecting the metal-braid sheathing on any serial DB9 connectors to the metal sheathing of the plug at BOTH ends, but only one. This could easily cause an earth loop through this connecting between the PC, mount and equipment via the earthing on the power supplies.
It never hurts to have a relay in place.
Brian Coote

http://bcoote-astro.com/default.htm

Carlos González Tirado wrote:

Hi all, someone has tried to connect the camera Sbig St2000xm to the
Fs2 controler? Need the relays controller?

Best regards

CarlosGT