Abstract: Aiming at the problems of complicated wiring and difficult debugging when controlling the relay control system of the direct-loading standard Brinell hardness machine,the work process of the hardness machine, the stability of the runtime, limit protection and the precision of the load test force and so on were studied,the basic principle of PLC control servo system was analyzed.A set of automatic control system based on the programmable logic controller , touch screen and servo system was developed.With CX-programmer as the development platform, PLC and touch screen technology and ladder programming language were used to establish the control system software, which realized the automatic control of the whole process of hardness machine loading and unloading, and the whole system was debugged and Brinell hardness verification test was carried out.The results indicate that the control system runs smoothly, improves the reliability and automation level of the hardness machine verification, and has the advantages of simple structure, high efficiency and wide adaptability.
Key words: standard Brinell hardness machine; automatic control system; PLC; servo system; relay control system；CX-programmer