Kara Systems BACnet:M-Bus User Manual - page 4
User’s Manual
Kara BACnet Gateway
Page 4
1
GENERAL INFORMATION
1.1 M-Bus
M-Bus (Meter-Bus) is a European standard (EN 13757-2 physical and link layer, EN 13757-3 application
layer) for the remote reading of gas or electricity meters. M-Bus is also usable for other types of
consumption meters. The M-Bus interface is made for communication on two wires, making it very cost
effective.
The M-Bus was developed to fill the need for a system for the networking and remote reading of utility
meters, for example to measure the consumption of gas or water in the home. This bus fulfills the special
requirements of remotely powered or battery driven systems, including consumer utility meters. When
interrogated, the meters deliver the data they have collected to a common master, such as a hand-held
computer, connected at periodic intervals to read all utility meters of a building.
1.2 Modbus
Modbus is a serial communications protocol published by Modicon in 1979 for use with its
programmable logic controllers (PLCs). It has become a de facto standard communications protocol in
industry, and is now a commonly available means of connecting industrial electronic devices.
Modbus allows for communication between many devices connected to the same network, for example a
system that measures temperature and humidity and communicates the results to a computer. Modbus
supports communication over EIA-485, EIA-232 and Ethernet TCP/IP
1.3 BACnet
BACnet is a communications protocol for building automation and control networks. It is an ASHRAE,
ANSI, and ISO standard protocol.
BACnet was designed to allow communication of building automation and control systems for
applications such as heating, ventilating, and air-conditioning control, lighting control, access control,
and fire detection systems and their associated equipment. The BACnet protocol provides mechanisms
for computerized building automation devices to exchange information, regardless of the particular
building service they perform.
1.4 Kara BACnet Gateway
The Kara BACnet gateway is a 2 in 1 gateway for BACnet. It integrates M-Bus meters and Modbus
devices sensors into BACnet. It represents a BACnet Device and several BACnet objects. M-Bus meters