Abstract: In view of the problem that traditional training methods for PLC debugging can not show the running states of controlled objects in full angles, a PLC virtual simulation training platform is designed based on virtual reality technology. The system is composed of upper computer and lower computer connected by RS232 bus. The upper computer uses 3ds Max to model and render facilities, and uses Unity3D to construct the complete virtual scene. The lower computer designs PLC control board to control the virtual gas-fired boiler, which transmits data between PLC and virtual scene through the communication module. The test result indicates that the system operates successfully. The learners can write and debug programs safely and efficiently. What's more, they can directly feel the processes similar to production sites, which improves training efficiency, shortens training cycle and reduces the cost of same degree training.

Key words: virtual reality, PLC, training system, gas-fired boiler, Unity3D