Buses, Protocols and Systems for Home and Building Automation

2. Closed systems
Evropský sociální fond. Praha & EU: Investujeme do vaší budoucnosti.
Closed building automation systems or proprietary systems are typically focused on family
and small houses. There exit tens of these systems on the market today. They are developed
not only by “no name” producers, but also by traditional companies like ABB or
Moeller/Eaton. Components for these systems are often offered in hobby retail chains like
OBI, Hornbach and Baumax, and in most cases they are cheaper than any system based on
an open standard.
Closed systems are usually complex, so they can solve all the basic tasks of home automation
– HVAC, light and shutter/blinds control, remote control (PC, PDA, phone) and so on. A
disadvantage is that they offer only very limited possibilities in functions, interconnections or
designs of devices. An advantage of this kind of systems is that they often do not need any
special training for installation and programming (often without PC, only using a
screwdriver). We can find centralized, distributed and also hybrid closed systems.
Closed systems are based on a proprietary communication protocol with wired (Nikobus) or
wireless connection (Xcomfort, Conrad FS20 and HomeMatic). Wireless closed systems are
becoming very popular today because their price is comparable to the price of a wired
solution with the advantage of easier installation (especially for older houses). Also more
and more producers start to offer systems with both types of communication – wired and
wireless (iNels).
2.1. ABB Ego-N
Fig. 2.1.1: ABB Ego-n (1)
Ego-n (2) is a centralized bus building automation system focused mainly on family houses. It
has its origins in the Czech Republic. The bus is physically realized by a 4-core cable with 2
cores for data and 2 cores for a power supply to the devices. There exist two types of buses
(Fig. 2.1.2): primary (max 700m length) and secondary (max 2000m length). The primary bus
connects sensors and actors (up to 64 devices on the bus) with a central control unit. The
secondary bus is optional and it connects up to 8 central control units, a GSM unit, a unit of
logic functions, a TCP/IP module and other high-end devices.
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