Data receiving device for M-BUS bus master station

Abstract

The invention discloses a data receiving device for a Meter-BUS (M-BUS) bus master station. In the data receiving device, a small-capacity current sampling resistor is connected in series in an M-BUS bus and the M-BUS does not have voltage drop basically, and has high slave station-carrying capacity and remote communication distance; voltage drop signals at both ends of the current sampling resistor are detected by adopting the differential current detection technology and are subjected to differential amplification, so the inhibiting effect on a common-mode input (interference) signal and the amplification effect on a difference-mode input (effective) signal are achieved effectively, and the sensitivity and interference resistant capacity are high; the receiving device has the function of the automatic adaption of loads and can adapt to the change of the bus loads automatically, so that data are received stably and reliably; and a current signal of the M-BUS bus is consistent with demodulated receiving data, is undistorted and does not influence data communication.

Description

technical field [0001] The invention belongs to the technical field of field bus control, and specifically relates to a data receiving device for an M-BUS master station, which can be used for water, electricity and heat meters of the M-BUS bus, industrial field instruments, fire alarms and linkage control, smart home, Buildings and communities and other fields. Background technique [0002] M-BUS (Meter-BUS, EN1434-3) is an international standard for consumer meters. It is an economical field bus with good openness. Its topology is bus structure. It is connected by ordinary two-core cable. Arbitrary topological structure wiring construction, its construction cost and difficulty are greatly reduced. [0003] M-BUS bus electrical interface shall meet the following requirements: [0004] When the slave stations are powered by the master station, each slave station can obtain no more than 2mA current, and the driving capacity of the master station should not be less than 64 ...

AI Technical Summary

Problems solved by technology

[0009] A large-capacity sampling resistor is connected in series on the M-BUS bus, resulting in a decrease in the output voltage of the M-BUS bus, which affects the communication distance and reduces the number of slave stations.

[0010] The sensitivity of the receiving circuit is not high, the anti-interference ability is poor, and the communication success rate is low

[0011] It cannot automatically adapt to the bus load change, and the bus load change caused by increasing or decreasing the slave makes the data reception unstable and affects the data communication

[0012] The current signal is inconsistent with the received data after demodulation, and the waveform is distorted, which affects data communication

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