BatiBus - already “history” for a long time, but still significant!

Building automation is a complex technical sector where, in addition to the use of conventional industrial systems for communication, other methods are required such as those of the BatiBus.
This was introduced first in the year 1989, but thanks to a replacement in the form of the KNX, it is no longer being marketed. However, the basis formed by the BatiBus is irrevocable. By definition, this is a concept of the open field bus which, in buildings and apartments, ensures that the components of the sensors, actuators, and other field equipment can communicate with each other. As such, the applications for this protocol included climate control and ventilation engineering systems, as well as lighting technology. Not least, the protocol also was used in security and alarm technology. Functionally, this concept consisted only of a TP cable which ran through the entire building and also served the sensors via the corresponding topology. The operation is basically divided into two sections:

  • Access procedure - this protocol is entered via CSMA/CA. This procedure makes it possible to enable each station to access the medium controlling the transmission. However, this can occur only as long as no other station in the system accesses the medium.
  • Paired cables and topologies - these sections of the BatiBus are subdivided into several segments. Here, the topologies can correspond to a star structure, a ring structure, a line structure, or a tree structure, all of which exhibit the benefits of a simple and cheap set up. Each segment has a power supply. This acts to supply of all network nodes, so that a total of 15 V and 150 mA is supplied to the lines. The network nodes themselves are configured via one of the possible 240 numerical addresses. As such, there are 240 different ways for making a connection to the network node. In addition, it is possible to configure a further 16 addresses which are in charge of group allocation. Via these addresses, all nodes that are within a grouping can be reached. The purpose of the network nodes with the BatiBus is the control of the data flow as well as the prevention of colliding data via CSMA/CA. The paired cables have two wires and have a max. data transmission speed of 4.8 kbps.

Expansion possibilities for the BatiBus and the importance of this

At first sight, the open field bus concept and this theme in general may seem confusing. Through the topology and the simplicity of the wiring, costs can be minimised. In addition, an expansion of the BatiBus was no problem at all. As such, each station of the protocol already had its own address via which it could be identified and reached. It was possible to carry out an expansion by simply adding further stations, which could also be removed again at any time when they were not required. Through its specification as a standard by CENELEC, the BatiBus also was considered a European standard, and in spite of having been replaced by its successor KNX, it still is one. Internationally, the protocol was standardized under the ISO/IEC standard as JTC1/SC25. Additionally, there is the ‘BCI Club’ for this technology. It already has over 80 members from various countries. Here, BCI stands for BatiBus Club International, which was founded in 1989 by the companies using this form of protocol. As such, companies from the field of air-conditioning/heating technology, automatic control engineering and lighting/installation technology can be found here. The BatiBus serves all branches of information technology and industrial communication.

The BCI Club has over 80 members from various countries, including companies in the field of air-conditioning/heating technology, automatic control engineering and lighting/installation technology.
Still, further development is meaningful and also necessary. Amongst others, the BatiBus was previously designed by Merlin Gerin, Airelec, and Landis & Gyr. It was to be one of the first fieldbuses, with the task of bringing automation to buildings. Like the field buses EIB and EHS, it was replaced by KNX. Although this ended the marketing of the original protocol, the BatiBus naturally still appears in its successor. The KNX, which has now become a field bus for building automation, is the specified standard for applications in commercial building automation and the residential building market. As such, this successor has been talked about since 1996 by the BCI, the EIBA (European Installation Bus Association) and the EHSA (European Home System Association). It was finally presented as a finished specification in the year 2002. The main objective was to develop a field bus with higher comfort and correspondingly higher flexibility than the KNX. From the technological point of view, the KNX was developed at the EIB using a new confirmation mechanism and a new transmission medium which was initially intended for the BatiBus and EHS. As such, the KNX is still connected to the EIB, and the initial protocol became a field bus assuming the role as a base for bringing progress to other protocols.