The Meter-Bus (M-Bus for short) is a two wire fieldbus, which is mainly used for meters to read measurement data. Many electricity, gas, heat and water meters can be read out via this bus. The device data can contain various instantaneous values, meter readings and device information. Modern energy management systems require the connection of M-Bus to the cloud.
For the cloud connection, the software module Universal Cloud Adapter is required. The Cloud Adapter can be installed on any Windows or Linux device (x86, x64 or ARM). The setup is explained in “Getting Started“. Alternatively, you can also use the AnyViz IoT Gateway.
The reverse polarity protected 2-wire bus is operated in the master/slave system. A master can read out up to 250 slave devices via its primary address. The cabling is not only used for communication, but also for the power supply of the participants, which is why a level converter is used. No uniform topology is required for the cabling. Even different topologies (e.g. string, star, etc.) can be mixed.
FunctionalityThe M-Bus is connected to the Cloud Adapter by using a level converter via a serial RS232 interface or an Ethernet interface. After creating a connection, the cloud adapter searches the specified address range and reads the values of the connected devices. Complex parameterization is not necessary, as all M-Bus participants describe themselves. The M-Bus subscribers and their values are then listed in the AnyViz portal.
In the M-Bus protocol, all necessary type information, factors and, if applicable, units of the measured values are supplied. The required conversions are carried out by the cloud adapter. Additional information, such as unit or tariff, is displayed in the cloud.
The primary address of each M-Bus station must be uniquely assigned. It is recommended to assign this address continuously in order to minimize the duration of the scan process.
The number of M-Bus participants is also limited by the level converter. It must be ensured that it is dimensioned sufficiently to be able to operate the desired number of bus devices.
If M-Bus subscribers are not listed after scanning, it is recommended to increase the timeout in the Cloud Adapter configuration.
With suitable cable quality, a bus length of up to 10km is possible.
