Numerical control system and numerical controller having display switching function

A numerical control system comprising a numerical controller, a management terminal, and a terminal device connectable to each other through a network,

• the numerical controller comprising:
• a numerical control unit;
• a Human Machine Interface (HMI) functional unit;
• a display unit;
• a connection unit for connection between the numerical control unit and the HMI functional unit;
• and
• a network connection unit for connection to the network,
• the HMI functional unit comprising:
• a display control unit that generates display data based on information received from the numerical control unit through the connection unit, and displays the generated display data on the display unit,
• the numerical control unit comprising:
• an error detection unit that detects an error in the HMI functional unit;
• a connection control unit that releases connection to the connection unit and sets up connection to the network connection unit if the error detection unit detects the error in the HMI functional unit;
• and
• an alarm notification unit that notifies a first alarm to the management terminal through the network connection unit,
• the management terminal comprising:
• a control unit;
• and
• a network connection unit for connection to the network,
• the control unit comprising:
• a first alarm detection unit that detects the first alarm notified from the numerical controller;
• and
• a second alarm notification unit that notifies a second alarm to the terminal device if the first alarm detection unit detects the first alarm,
• the terminal device comprising:
• a display unit for display of data;
• an HMI functional unit;
• and
• a network connection unit for connection between the network and the HMI functional unit of the terminal device,
• the HMI functional unit of the terminal device comprising:
• a second alarm detection unit that detects the second alarm notified from the management terminal;
• a connection control unit that connects to the numerical controller through the network connection unit of the terminal device if the second alarm detection unit detects the second alarm;
• and
• a display control unit that generates display data based on information received from the numerical controller through the network connection unit of the terminal device, and displays the generated display data on the display unit of the terminal device so that a user is able to input an instruction or data based on the generated display data.