Patent ID: 7977908

Claim:
A numerical controller comprising: a servo section for controlling a motor; a programmable machine controller section for controlling DI/DO signals for a machine; a numerical control section which issues a command to the servo section and exchanges data with the programmable machine controller section; abnormality detection means for detecting an abnormality of the numerical control section; and motor deceleration stop control means which is provided in the servo section and decelerates and stops the motor so that the motor is subjected to a torque that causes a movement in the opposite direction based on speed feedback control, on receipt of an abnormality detection signal, indicating abnormality of the numerical control section, from the abnormality detection means, wherein said motor deceleration stop control means is provided with signal delivery means which delivers a signal for turning off a DO signal to the programmable machine controller section when an actual speed of the motor becomes not higher than a preset speed, and said programmable machine controller section is provided with means which receives the signal for turning off the DO signal from the signal delivery means and which turns off the DO signal for a brake device, thereby activating the brake device.