R.D. stands for relocation device. This detects when the machine is moved and trips something in the control so it does not work. This is how Mazak keeps track on where their machines are. (so, they don’t break trade laws). Once tripped (will trip if battery dies or you possibly bump this unit inside of the electrical cabinet.) only Mazak can reset by sending out a technician.
DO NOT SHUT OFF the machine until the battery has been replaced. As with all other batteries in the control or you may lose parameters. The R.D. is a 3″ x 3″ black box inside the electrical cabinet.