The Design Of Seismic Exploration Data Acquisition Unit System Based On CPLD

Seismic exploration instrument is the important equipment in process of seismic exploration. Independent researching and designing seismic data acquisition recording system have a very important realistic meaning and profound historic significance in strategies, technical requirements, competition security and markets demands. The degree of China's oil foreign dependence climbs up every year. It has seriously affected the country's economic sustainable, stable development and national security. To solve this problem, upgrading our country's independent oil exploration and exploitation ability is the fundamental path. Developing the new generation high precision digital seismic data acquisition system of proprietary intellectual property rights is the urgent requirement of oil exploration industry. This paper relies on the state 863 project"digital million channel high precision seismic digital acquisition system". With the technical accumulation in project actual development process, the high precisionΣ-△A/D conversion and CPLD technology as the main body structure, this paper designs high resolution seismic data DAU system.This paper mainly proceeds in designing for the DAU of seismic exploration instrument. Data acquisition functions of DAU mainly based on high precisionΣ-△A/D conversion technology to realize, with CPLD chip as the core components of data processing and transmission. Using RS-485 data transmission method to realize data remote transmit. The design integrated multi-channel signals select distribute unit, programmable amplifiers, 24 bitsΣ-△ADC of many sampling rate and digital extraction filter to configuration seismic data acquisition system. With 8051 microcontroller to sync system collect action. Using digital design technology based on CPLD/FPGA to process collect data. Using Verilog HDL code and gate schematic to complete software designing improve the data processing speed and precision and optimize the scale of the whole system hardware circuit design. Finally using RS-485 to realize the remote transmission and stack the collected data into PC.This paper develops from the topic necessity, the domestic and foreign relevant research dynamic analysis and realization method etc and makes a detailed theoretical analysis and description of the whole system. This paper mainly obtains the following research achievements: Completing the hardware circuit schematic design and carrying through a small amount PCB's manufacture of DAU; CPLD chip combining with software realizes the whole data processing and transmission function, and verify the correctness of the logic function by the simulation; On the basis of correctly realizing DAU system hardware and software, Connecting and debugging 30-channel DAU, Under the two work patterns we get 30-channel sine wave figure and seismic wave signal figure of seismometer; The power module of seismic data acquisition transmission system based on low power consumption process in the design and used various kinds of low power consumption conversion chip as many as possible, Significantly reducing the whole system power consumption.The advancement and innovativeness of system design mainly reflects as follow: The high precision 24 bitsΣ-△ADC is good at increasing resolution and dynamic range of acquisition data; using digital logic design based on CPLD reduces the hardware scale of circuit design, The software part is easy to simulate and test; the low-power consumption considering of system power supply module can reduce the batter's quantity in field actual exploration and is good for reducing human, material and financial resources. The successful design of seismic data DAU system laid a solid foundation for the project's ultimate goal of"develop digital seismic acquisition system with 100,000-channel".