M-Bus ("Metre -Bus" ) is a new European standard used in order to read remotely the data regarding the consumption of heat flow meter and other type of meters and the values of sensors, actuators. The data (i.e. heat consumption) is read electronically via two cables. The meters in the living areas are connected to the M-Bus communication cable. And the M-Bus convertor is used in order to collect the data of the meters on this line.