A communication method of m-bus

Abstract

The invention provides a communication method of an M-BUS (meter-BUS), and the method is suitable for a slave in an M-BUS system to receive signals sent by a host. The slave comprises a singlechip, a communication interface module, a direct current supply module and other functional modules, wherein the communication interface module comprises a bridge rectifier circuit and a resistance voltage division circuit. The method is characterized in that after the signals of the M-BUS system host, which are input into the slave, are rectified by a rectifier bridge, the voltage of the signals is divided by a resistance network, the signals subjected to voltage division are directly connected with the input port of an ADC (analog to digital converter) an ADC module is used for measuring the input signals, the boundary thresholds of the high and low electric signals input via the M-BUS are computed according to the values obtained after measurement, after setting of the boundary thresholds is completed, the ADC module or an analog comparator module is started and communication monitoring on the signals input via the bus is completed by comparing the input signals with the boundary thresholds, thus achieving a communication data receiving function. The slave has the characteristics of strong antijamming capability and low cost.

Description

Technical field: [0001] The invention relates to a communication method of M-BUS bus, which is suitable for the slave device in the M-BUS bus system to receive the signal sent by the master device, especially the data transmission method in the system which forms a network with the management host through the M-BUS bus. Water meters, gas meters, electricity meters and other alarm and monitoring equipment. Background technique: [0002] In recent years, the Meter-BUS bus conforming to the EN1343-3 standard, referred to as the M-BUS bus network, because its communication only needs two-core wires, non-polarity input, and star connection, it makes the construction easy and greatly reduces the construction labor. Strength, improve the stability of the system, so that the communication network of the M-BUS bus has been widely used in the remote digital meter reading system and the alarm monitoring system. Usually, the slave device (Slave) is encoded and decoded by the ASIC chip. ...

AI Technical Summary

Problems solved by technology

[0002] In recent years, the Meter-BUS bus conforming to the EN1343-3 standard, referred to as the M-BUS bus network, because its communication only needs two-core wires, non-polarity input, and star connection, it makes the construction easy and greatly reduces the construction labor. Strength, improve the stability of the system, so that the communication network of the M-BUS bus has been widely used in the remote digital meter reading system and the alarm monitoring system. Usually, the slave device (Slave) is encoded and decoded by the ASIC chip. However, the price of the ASIC chip is too high, which makes the cost of the product very high, and inhibits the promotion of the M-BUS bus system. Moreover, the integrated circuit packages the rectifier components and power supply components input by the M-BUS bus together at the same time. The constant current source structure that absorbs no more than 10mA from the bus, and the output voltage is only 3.3V, which further inhibits the promotion of the bus system

[0003] In order to reduce product costs, many people try to use discrete components to form the functions required by the M-BUS bus protocol specification, but usually in addition to a set of rectifier bridges, multiple triodes, multiple diodes, and several resistors and capacitors are required. Individually, at least one large-capacity capacitor is required. The use of large-capacity capacitors increases the capacitive interference of the M-BUS bus system and easily causes communication instability; the use of a large number of separate devices increases the number of failure factors and also It will increase the size of the circuit board, which is not conducive to the use of products with limited circuit board installation volume such as water meters. In this way, although the product cost is reduced, the performance of the product is also reduced, and it is difficult to have a wide prospect

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