Cant tell from the photo, do you have positioning motors on the machine? Are they Stepper motors? if so it could be the feedback from steppers and the board may be the stepper control board. Regards Badger.
it is an RS485 Communication terminal strip.
it can be wired either as a 4 wire system or a 2 wire - note the terminating resistor
If you can take the card out of it's holder see what is on the back or sides for info