Which one of the following is not a function of servo-sub system in CNC machines?

Explanation:

CNC Machine:

• In a CNC machine, there is a dedicated computer that is integrated into the control to perform the basic and advanced NC functions. The computer allows the storage of additional programs, program editing, running of programs, and control diagnostics. For the CNC machine, it is very easy to change the programs while in an NC machine every time the program is changed in the tape and fed into the machine again.
• In the CNC machine tool, the encoder is used to sense and control the table position.

Functions of the servo-sub system in CNC machines:

• Profile Generation
• Feedback processing
• Position and velocity control 

Automatic Tool Changer(ATC):

• An automatic tool changer (ATC) is used in computerized numerical control (CNC) machine tools to improve the production and tool-carrying capacity of the machine.
• ATCs change tools rapidly, reducing non-productive time.
• They are generally used to improve the capacity of the machines to work with a number of tools.
• They are also used to change worn-out or broken tools.
• The main parts of an automatic tool changer are the base, the gripper arm, the tool holder, the support arm, and the tool magazines.
• Although the ATC increases the reliability, speed, and accuracy of a machine, it creates more challenges compared to manual tool change.
• For example, the tooling used must be easy to center, and easy for the changer to grab, and there should be a simple way to provide the tool's self-disengagement.
• Tools used in ATC are secured in tool holders specially designed for this purpose