The Design And Implementation Of The Heat Meter Date Acquisition Unit Based On M-Bus

With the improvement of people’s energy-saving awareness and the introductionof national relevant policies, the heating of residents in our country changes graduallyfrom the fee system according to residential area into charging fee according to theactual use of heat. Such a door a meter according to the amount of heat charging feescan improve the energy saving consciousness of users. With the gradual popularizationof a door a meter, how to realize the data’s access and automatically copy read becomesa new focus.Two-wire bus M-Bus (Meter Bus) is set specifically for consumer households touse the copied instrument for the development. It adopts modulation of voltage andcurrent, with the longer distance communication, load heavy, indiscriminating positiveand negative, any topology, convenient installation and other characteristics. In the“heat meter” standards promulgated by the Ministry of Housing and Urban, it wasclearly defined that Automatic meter reading preferred the M-Bus interface. Based onthe M-Bus calorimeter centralized meter reading, this paper does the research on thedata acquisition, designing out an inexpensive, data transmission accurate, load capacitystrong heat meter data acquisition unit.This paper covers how to implement the M-Bus signal modulation anddemodulation, and how to realize the availability of data acquisition unit, inmulti-application environment, the main research work are as follows.1. M-Bus collectors on the market are expensive, and the species is less. Takinginto account the gradual promotion of the heat meter with M-Bus interface, the demandhas also increased for M-Bus data acquisition unit, such results in many problemscoming out. This paper does the research on the M-Bus protocol and analyses theM-Bus signal modulation and demodulation as well as designing the hardware circuit. Acombination of simulation and experimental retaliates the M-Bus bus signal modulationand demodulation;2. For M-Bus data acquisition unit with limited power output resulting in loadcapacity limited, we consider using the relay for channel switching, multiple channeltime-sharing use of modulation and demodulation part of the circuit, thus effectively itincreases the load capacity of the data acquisition unit and enhances the costperformance of the data acquisition unit;3. Since the M-Bus data acquisition unit only plays a role in signal conversion, itmust matches the host computer to capture data from the slave computer Instrument, Ifthe host computer fails, the data of the slave computer will be lost. To this end, for thedefects of the data acquisition unit, we design the data acquisition unit intelligently to achieve automatic acquisition and data local-storage capabilities of data acquisition unit,so that it can realize independent data collection and local-storage in the case that thehost computer communication breaks down;4. Usually the data acquisition unit needs to be installed on the scene, away fromthe data center. For the issue that how to aggregate the data of the data acquisition unitto the data center, we design the GPRS data remote transmission modules and networkinterface module, realize data remote transmission in the various ways.