The Implementation Of Line Manage Uint In MTEM System

Geophysical exploretion as a method and theory researches and explores the earth’s internal structure and resource distribution,which is significant for economic develop-ment, city specification, resourse exploration and so on. Multi-channel transient electro-magnetic survey, based on electromagnetic induction, is a time domain electromagnetic detection method. It has advantages of higher dynamic range of EM data, higher reso-lution and wider range of spatial coverage and have been widely used in geology and mineral resources, petroleum, coal, engineering geophysical and other industries.Data return of data acquisition system in geophysical instruments is the first step in the ex-ploration process, also is the premise and guarantee of data processing and analysis. The new request of acquisition system and LMU in system is proposed by increasing of channels numbers, extending distribution, improving resolution and rising number of acquisitions. The thesis analyses the devepment of LMUs in existing acquisiton system in our country and abroad, of which the high power dissipation(>5.7W), low bandwidth utilization(<78%) problems cannot meet the new requirements put forward by the de-velopment of geophysical survey system.The thesis introduces a new design of high-speed, reliable and controllable LMU(Line Manage Uint) based on Ethernet physical layer, using dedicated hardware interfaces and low-power MCU to implement reliable data transfer protocol. Different with the commonly used TCP/RUDP mechanism, the implementation of transfer protocol with dedicated hardware interfaces ensures higher data transfer rate compared to other im-plementation used only software, when sharing similar CPU frequency and power dissi-pation. Also it’s capable to distributively manage the data acquisition system. Having been tested, the LMU is able to realize99.9%bandwidth utilization of Gigabit links and Fast links, with power dissipation about3.5W and the characteristics of reliable data transfer and low-power dissipation.The first chapter, based on the introduction of geophysical exploration methods, clarifies the main content and features of multi-channel transient electromagnetic ex-ploration technology. It also introduces general constitution of geophysical exploration data transmission system, and describes the topology in which the LMU and its hard-ware interface.The second chapter describes LMU’s design background and realization basis. Starting from the current status of LMUs in geophysical prospecting equipment, it an-alyzes the requirement which data acquisition system requests for LMU and cites in part the high-speed data transfer protocol, as foundation of high-speed and reliable data transmission and implementation of distributed systems management.The third chapter illustrates specific methods of the LMU’s design and implement, including the LMU’s hardware platforms and architecture, communication interface, protocol implementation and management of distributed software.The fourth chapter is performance testing part. It describes the design and imple-mentation of data sources, analyzes and tests the LMU’s data rate, command response speed and efficiency as well as power consumption and so on.The final chapter summarizes and outlooks the main work about design and im-plementation process and the content of next step need to be improved.