Basic Component of Numerical Control NC Technology
An NC system consists following components.
- Program instruction
- Machine control unit (MCU)
- Machine controlled process (tool)
Program instructionProgram instruction is served as the input into the controller unit. It is a detailed step by step instruction which tells the machine tool what/how to do. Each instruction specify the position and movement of machine tool. This detailed set of command is coded into some type of input medium which is then interpreted by the controller unit. The most common method of inputting instruction is punched tapes.
Machine control unit (MCU)This component consists of electronics and hardware which read and interpret the program instruction and convert each command to the action of processing equipment. The elements of control unit include of tape reader, a data buffer, signal input channel to the machine tool and the feedback channel from the machine tool. It also consists the sequence control to coordinate the whole operation of preceding element.
The tape reader is an electromechanical device which used to reading the instruction on punched tape. Then this data is read into the data buffer. The signal output channels are connected to controls of the machine tool (servomotors). The instructions are sent to the machine tool through these channels. Then the feedback data sent back to control unit through a feedback channel. The purpose of the feedback system is that to make sure about the proper execution of the input instruction. The sequence control the all the activities of other control elements. It synchronises the operations such as the reading of punched tape, sending signal to and from machine tool.
Read : What is CNC (Computer Numerical Control)? Advantages, Limitations, Applications