What is M-Bus

M-Bus (Meter Bus) is an instrument bus. The purpose of developing M-Bus is to meet the needs of network systems and remote meter reading. M-Bus is the product of Dr. Paderborn University.wireless communication solutions  Horst Ziegler and TI's Deutschland GmbH and Techem GmbH jointly proposed a bus structure specially used for public utility instruments. The full name is Meter-Bus, or M-Bus for short.

In the OSI seven-layer network model, M-Bus only defines functions for the physical layer, link layer, network layer, and application layer. Since the ISO-OSI reference model does not allow changes in the upper layer such as baud rate, Address and other parameters, therefore M-Bus defines a management layer outside the seven-layer model, which can manage any layer without complying with the OSI model.

M-Bus has the characteristics of simple wiring, topology independence, and strong anti-interference. Low-power wireless communication Its applicability in non-electric instruments is obviously better than RS485, Lonwork and other transmission methods. It has been widely used in building and industrial energy consumption data collection.

The M-Bus system uses half-duplex asynchronous communication, with a transmission rate of 300~9600bps and a long transmission distance. WiFi Wireless Module The bus connection method adopts a bus topology and can connect hundreds of slave devices over a distance of several kilometers. M-Bus is a hierarchical system, consisting of a master device, several slave devices and a pair of connecting cables. All slave devices are connected to the bus in parallel, and the master device controls all serial communication processes on the bus. The typical M-Bus bus framework is as shown in the figure below, where Master represents the M-Bus bus controller and Slave represents the instrument equipment hanging on the bus, which is the master-slave response mode.

M-Bus bus characteristics

(1) Two-wire bus, no positive and negative poles, simple construction;

(2) Use unique level characteristics to transmit digital signals, with strong anti-interference ability and long transmission distance;

(3) Bus power supply can be selected to reduce maintenance costs;

(4) Bus topology, easy expansion and low networking cost;

(5) The failure of any slave station does not affect the function of the entire bus;

(6) Specially designed message format to meet the needs of energy consumption meter networking and remote reading.