Method and implementation of constructing numerical control language based on PLC multilayer architecture

DONG Lu，YAN Yi，WU Huifeng
(College of Computer，Hangzhou Dianzi University，Hangzhou 310018，China )

Abstract: In the PLC with motion control functions, it is necessary to modify the PLC control programs and adjust the parameters constantly for motion control programs written with ladder diagram in debugging and optimization process, which will lead to the problem of low development efficiency. Aiming at this problem, a method to construct the numerical control language on the PLC was proposed. The implementation process to construct numerical control language was described in detail, including the design and implementation of the numerical control instructions, the compilation and execution of the numerical control programs. The way to implement the functions of numerical control instructions with PLC modular programming method was stressed, then the resolution and execution control algorithms of the numerical control programs were given out. At last, a specific example of building numerical control language layer on the customized embedded PLC was presented. The results indicate that the approach can conveniently adjust the sequence of motion control and setting parameters, which can effectively reduce the number of PLC control codes and improve the developing efficiency greatly. Besides, the method can quickly customize the corresponding numerical control language according to the different applications, so that it can meet the requirements of flexible control needs, and be suitable for industrial control.
Key words: programmable logic controller (PLC); numerical control language; ladder diagram; motion control