The Development Of Two-phase Flow Metering Unit Based On GPRS Communication

Based on the analysis of the overall function of the flow metering system, the PCmonitoring software and the wet gas flow metering unit are designed and implemented tomatch the flow of wet gas flow metering system of wellhead metering and remote monitoring.The metering unit hardware circuit and software are optimized in this thesis. Thehardware design involved in this paper consists of several parts as follows: utilizing a serialFlash memory for the storage of process and important data, utilizing a ferroelectric memoryto store the traffic data and design the metering unit reset and power-down protection circuit,utilizing a LCD controlled by CPLD and a keyboard interface, designing a interfaceconversion circuit for the communication of DSP and GPRS module and the designation ofGPRS modules peripheral circuit, completing the design of every circuit module schematicand metering unit PCB in Altium Designer. The software design involved in this paper couldintroduced as the following parts: serial Flash data access program in C language on CCS2.0development platform, DMA data access program, the ferroelectric memory data accessprogram, and power-down protection program, remote communication control of GPRSmodule, keyboard program to integrate the various functional modules of the metering unitand the embedded real-time operating system DSP/BIOS for unified scheduling of eachthread. The VHDL language is utilized to achieve the disappears shakes of keyboard and theLCD serial data transmission in the Quartus II.The PC software is written in C++Builder environment. It includes the design ofman-machine interface, user management unit, flow meter snap, database management unit,network communication unit, the data processing unit, and the fault diagnosis unit. Themonitoring center host computer works in the server mode to achieve positioning andmanagement for each meter, traffic data storage and display, fault diagnosis.