Numerical controller

A numerical controller in which a plurality of devices is allowed to be connected to a serial bus by a daisy chain, the numerical controller comprising:

• a connection information acquisition unit for acquiring, from each of the devices, a connection number indicating a connection position of the device on the daisy chain and a device ID corresponding to identification information unique to the device as connection information;
• a connection information comparison unit for determining presence or absence of a problem by comparing the connection information with a connection setting parameter obtained by associating the connection number with a logic axis number corresponding to identification information of a logic axis of the numerical controller;
• a connection information storage unit for storing the connection information acquired by the connection information acquisition unit when there is no problem in the determination;
• and
• a connection setting data creation unit for identifying a removed device by comparing the connection information acquired by the connection information acquisition unit with the connection information stored in the connection information storage unit when there is a problem in the determination, and excluding the removed device from the connection setting parameter, thereby creating connection setting data.