Digital Readout(DRO) system is a kind of detection device that shows linear displacement for machine tool equipment.,it can install on all machines. Processing functions 1) PCD circular sub-holes (for milling, EDM) 2) Slash punch (for milling machine) 3) Tool compensation function (for milling machine); 4) Taper measurement function (for lathe); 5) Slope processing (for milling machine); 6) R arc function (for milling machine); 7) 200 tool magazine (for lathe); 8) EDM functions (for EDM)