I heard that the SL2-100 protocol has higher resolution and is more reliable than the XY2-100 protocol when using long distance transmission, from customers in laser welding field. As I know it only has two lines DataIn+ and DataIn- plus two Lines DataOut+ and DataOut- and supports 20 bit scanner resolution. Has anybody an idea how the protocol looks like and works? Any documentations out there that describes SL2-100 protocol specification?

Thanks!