Design Of Underground Network Substation Based On ARM

At present, coal exploitation most carried underground. The safeties of coal mines are still outstanding. There are many landslips of coal mines and fire damp explosion (gas explosion) happened, which endanger the lives of the miners and cause much property loss. So the coal mine safety monitoring system is applied to the coal mine industry widely. And it plays an important role in the the process of coal exploitation.This thesis originates from the project "The coal mine safety monitoring and management system". The system will not only develop and perfect some key equipment, such as the explosion-proof industrial Ethernet Switch, underground intelligent control substation, and so on, but also perfect the integrated information management system. So as to lead the system to realize the function of intelligentized aided decision-making and automation control.As an important part of the coal mine safety supervision and management system, a network substation based on ARM micoprocessor is designed in thesis which can be used underground. This substation regards the real-time operating system μC/OS-II as operating platform, realizes the communication with ground computer via embedded TCP/IP protocol stack. This substation removes the disaccords among different underground substations.In the hardware, according to the "General technical requirements of coal mine safety supervision", the thesis completes software and hardware designs of the substation. And the Ethernet connecting is realized by RTL8019AS in hardware. ARM microprocessor LPC2214 which has 16KB on-chip Static RAM, 256KB on-chip high speed Flash Program Memory is used as the master control chip in the substation. In addition, the LPC2214 microcontroller has 8-channel 10-bit A/D converter with conversion time as low as 2.44μs, multiple serial interfaces and up to 76 general purpose I/O pins (with external memory). It goes without saying that it is particularly suitable for industrial control. With a wide range of serial communications interfaces, it is also very well suited for communication gateways as well as other general-purpose applications. The substation has the man-machine conversation interface of LCD Displaying and Key-press. It can communicate with the ground computer via TCP/IP protocol. A more complex algorithm is realized by the ground computer.In the software, the embedded operating system μC/OS-II is transplanted to the LPC2214 base on which the TCP/IP protocol stack is realized. Data format of exchange is established. And TCP/IP protocol is used to communication between the underground substation and ground computer. At last the thesis introduces the thinking in program of several program modules in tail, such as the module of LCD displaying, the pulse signal with a defined frequency counting and data storing, etc. At the same time, the solution of some problems in the practical programming are put forward.According to the standard "Intrinsic safety "i"", the control substation has implemented electrical isolation with the external electrical apparatus. The substation has two A/D data collecting, six photoelectric isolation digital inputs, two photoelectric isolation digital outputs, man-machine conversation interface, RS485 interface, and internet communication interface. The noticeable point is that all parameters collected can be protected well when they are in the state of power breakdown. The substation has not only realized the functions, data collecting, sound and light alarm, key-press processing, LCD displaying, but also realized bidirectional communicate with ground computer.