As manufacturing enterprises continue to expand and equipment automation levels increase, China's machine tool products are gradually moving towards high-end products. These machine tools require the use of a large number of PLCs and motion controllers/cards to gradually replace relays or mechanical controls, thereby improving the overall performance of the machine tools. Therefore, in the long run, the application of PLCs and motion controllers/cards still has great potential.
"After maintaining rapid growth in recent years, the machine tool industry has begun to show signs of decline, particularly affecting conventional machine tools, which are experiencing increased inventory. The impact on CNC machine tools is slightly less pronounced, leading to a reshuffling of the industry. The development of CNC and high-end machine tool products is creating huge demand for PLCs and motion controllers/cards," said Luo Baihui, chief analyst at Jinmo Machine Tool Network. He believes the future direction of machine tools is CNC automation and gradual upgrading. These machine tools will require a large number of PLCs and motion controllers/cards to gradually replace relays or mechanical controls, thereby improving the overall performance of the machine tools. In the long run, the application of PLCs and motion controllers/cards in the machine tool industry still has great potential.
CNC machine tools are mechatronic products integrating computer technology, PLC technology, and automation technology. The control system, as the core of a CNC machine tool, directly affects the normal operation of the equipment. Utilizing the powerful functions of the CNC machine tool's PLC can fully leverage the role of the control system and greatly facilitate fault diagnosis and maintenance. The safety control function designed by the author for a machining center to prevent machine tool collisions effectively eliminates the hidden dangers of collisions between the machine tool spindle and fixtures/workpieces caused by operator error, ensuring production safety and providing good economic benefits.
PLC stands for Programmable Logic Controller. The PLC used in CNC machine tools is also called PMC. It has the following advantages: fast response, high control precision, good reliability, control programs can be changed according to different applications, and it is easy to interface with a computer and maintain. Typically, the PLC program used in CNC machine tools includes a system program and a user program. The system program, including monitoring programs, compilers, and diagnostic programs, is provided by the PLC manufacturer and is stored in EPROM; users cannot directly access it and do not require user intervention. The user program is an application program written by the user using a PLC programming language to achieve various control requirements based on the needs of on-site control. Commonly used PLC programming languages include ladder logic, statement lists, and function block diagrams.
Since many of the actuators of a CNC machine tool are controlled by PLC commands, the PLC can be used to quickly detect and repair faults in the CNC machine tool, or to add an executable action or function to the CNC machine tool by modifying or writing the PLC program.
