With the vigorous development of modern engineering construction in the 21st century, a large amount of complex comprehensive supporting equipment has been invested, and its complex process flow and many independent operating components require relatively high performance of its equipment control system. The application of PLC in asphalt mixing plants has realized the control of the entire process of asphalt mixing plants, facilitating the construction of modern engineering projects.

 

Modern highways are gradually flourishing, and the most commonly used equipment is asphalt mixing equipment. In practical control, asphalt mixing equipment mainly controls feeding, temperature, metering, finished products, and dust removal.

 

Generally speaking, the application of PLC in asphalt mixing plants has certain application characteristics. On the one hand, the dynamic dosage of asphalt mixing plants not only has a fast PLV calculation speed, but also has a relatively short scanning cycle, basically controlled within 10ms. On the one hand, its equipment has many control points, often requiring PLC to have relatively large memory and margin, while also having relatively fast communication speed, with a refresh rate of more than 5 times/s for its upper level screen. On the other hand, the application in asphalt mixing plants has achieved the expansion of the asphalt mixing equipment system, with low cost reduction, relatively high performance, and a focus on improving the performance price ratio of the entire machine.

 

The commonly used control system of PLC in asphalt mixing plants is mainly based on Siemens PLC. Currently, the S7-400 equipment has relatively fast speed, large memory, and excellent performance, but this equipment has a high price. Although the S7-300 device has a lower cost, its performance is relatively low.

 

 

As for the high-performance PLC of S7-300/400, it not only has faster running speed, larger memory, and more communication interfaces, but its programming is also compatible with Step7, and there is no need to make one-sided modifications to the program.

 

The improvement of equipment performance and cost reduction often depend directly on the performance of PLC applications. The main components of centralized control systems include 300S-CPU, 300V digital output template, 300V digital input template, 300V analog input template, and 300V analog output template.