What is M-Bus ?
It is an abbreviation that comes from the words Bus. M-Bus is a standard developed for the communication of measuring devices.This standard is a standard used in the measurement of measurement devices such as Electricity, Water, Natural Gas, which are generally used in homes.
M-Bus standard has improved by Professor Dr. Horst Ziegler from Paderborn University.
M-Bus equipments can receive energy over the cable as well as be fed with batteries. When the M-Bus counters are questioned by a master equipment, they transmit the collected information to the master equipment.
M-Bus master unite can be wired or not. Devices such as a hand computer, M-Bus collector are connected to the counters periodically and receive consumption information.
M-Bus equipment should not be questioned too often, especially when they are powered by batteries. Since each query generates an energy consumption, the ideal query frequency is once a day.
In case the cable infrastructure is ready, M-Bus counters can take their energy over the cable. In this case, more frequent queries will not cause any problems.
In the wired M-Bus application, a pair of signal cables is installed and all M-Bus equipment is connected in parallel to the cable (BUS). Devices connected with M-Bus collectors in the center receive the energy supply over the cable. At the same time, Counter information is transmitted to the collector in the center over the cable.
This system, which has a very low cabling cost due to the use of bus topology, is particularly suitable for apartments.
M-Bus is a protocol that communicates serially over a pair of cables. If this structure is installed, it is possible to energize the counters remotely.
Standard telephone cable is used in the configuration of the M-Bus cable system (JYStY N * 2 * 0.8 mm). The maximum recommended length for this cable is 350 meters.
A maximum of 250 meters can be connected in one M-Bus segment.
Communication speed in M-Bus cable communication can be adjusted between 300-9600 bps. Cable distance can be extended by reducing the speed and reducing the number of meters connected. In this case, it is recommended to adjust the cable diameter and to have the capacitance value lower than 180nf. However, it is recommended that the cable distance does not exceed 1000 meters in any way.
There is no difference between the wired M-Bus and the wireless M-Bus in terms of the information transmitted. Wireless M-Bus makes it possible to feed the with batteries, as it is an energy efficient protocol.
Battery life of 10 years or more is recommended for devices using the wireless M-Bus protocol. Considering that the legal period for the calibration of the counters is 10 years, additional labor will not be required for battery replacement.