Research On Embedded Gateway In Coal Mine Safety Monitoring Network

At present, the coal mine safety monitoring system is applied to the coal mine industry widely.And it plays an important role in the process of coal exploitation. However, there are still many industrial monitoring equipment through RS-232/485 communications protocol or CAN Fieldbus protocol such as the composition of lightweight network at industrial field. These networks are an effective radius of the limited, related communication protocol is also less. Above all, the data can not be directly exchanged between Internet and Intranet. It is incompatible for the current development. And it is evry meaningful to solve these problems in the safety monitoring network.This paper studies the embedded gateway based on the embedded operating system, at the upper, it realize data transmission network communication module by TCP / IP protocol in the Ethernet environment. At the bottom, it realizes interconnection between computer networks and heterogeneous Fieldbus that using the certain communications and industrial Fieldbus protocol combine. And the embedded gateway is one of the core components to the mine safe production platform for digital control systems, so construct a mine environment, low-cost, reliable, secure embedded gateway, it has theoretical and practical significance to realize interconnection between Fieldbus and Ethernet, according to the characteristics of them.This paper fastens on two aspects: realizing embedded system connecting to Internet and the interconnection of several embedded heterogeneous networks.In this paper, the elementary theory of embedded Internet is studied as a foundation. Based on embebdded operation system Linux, the gateway is designed to interconnect the embedded heterogeneous networks. Communication protocols of the CAN bus network,Ethernet, hardware frame and the software system of this gateway are discussed in detail. Analysis of the introduction of, CAN bus, Ethernet device driver implementation process base on embedded Linux operating system are analysised. This gateway uses the modular design way, integrates many kind of embedded heterogeneous networks. Through this gateway, not only the low performance embedded equipment can be linked to Internent, but also a software frame which is suit reducing and expanding and easy to transplant is given to interconnecte several isolatedembedded heterogeneous networks. In addition, this design uses the embedded Linux operating system, thus the real-time performance of embedded gateway is improved.The application environment is simulated in lab, the test to the reliability and exactitude of interface and performance is done. The experimental results show that IU can performance correctly and implement the protocol conversation faction between CAN and serial bus. That provides experience to protocol conversation in more complex environment.