wilamowski-b-m-irwin-j-d-industrial-communication-systems-2011

26-8 Industrial Communication Systems
lighting systems are examples of alarm processing systems. Shutters are frequently found to use Modbus
to control them. LonWorks can be found in a number of emergency lighting installations. The main task
is to react to a building alarm and constantly monitor the health status of emergency light devices as well
as the generation of alarms to the operator as soon as they show failures.
To operate a building, supervisory control and data acquisition (SCADA) systems are frequently
used. These high-level management systems collect and visualize operational data from the building
and provide parameters to the building manager for configuration of building services. As opposed
to low-level control loops, the timing aspects of these systems are very relaxed. Still, SCADA services
must exhibit high reliability. To improve reliability, the data acquisition may be distributed and placed
as near to the field level as possible. In this case, the subsystems can function autonomously in case the
backbone or central SCADA fails to operate. Trending of data is partly already done in building controllers
or even lower in the system, and SCADA systems only need to collect and store data in batch cycles.
Room control panels are also examples of a small SCADA service in rooms or corridors.
Traditional BAS are often installed by different contractors for different building service domains.
This means that in the past, almost no cross-communication existed between service domains. The
emergence of new, tighter integrated building services, however, now requires different domains to
share data. Examples are data exchange between presence detectors from lighting with HVAC or controlling
sunblinds of the lighting domain from the HVAC service. From a communication viewpoint,
this requires horizontal integration. Performance contracting and energy monitoring also demand a
global view of the building across different building service domains. These are high-level systems that
need access to data in the lower levels of the BAS. This is the area of vertical integration.
26.3 Home Automation
26.3.1 Motivation and Overview
Adopting automation technology is equally attractive in the residential domain. Besides efficiency considerations,
increased comfort and peace of mind are key motives here. Also, elderly people can live
in their own homes longer (ambient assisted living, smart home care). The importance of this aspect
continuously increases as life expectancy does.
Although the number of devices involved in a home automation project is by orders of magnitude
lower than for large functional buildings, the complexity of such projects must not be underestimated.
While many applications and techniques are similar to the ones found in building automation, additional
challenges arise in systems tailored to people’s needs in private households. Additional application
domains (household appliances and consumer electronics) must be integrated. Easy configuration
is of particular importance, since the disproportionately high setup cost will otherwise reduce the
attractiveness of automation. Acknowledging these specific challenges, one explicitly speaks of “home
automation” systems (HAS).
A key challenge is the integration of the traditional automation domains (HVAC, lighting/shading)
with the many established services in the home such as home appliances, telecommunications, multimedia,
as well as energy metering and security devices. Solutions that want to persist in the home
market must guarantee a seamless integration of these heterogeneous systems (both in terms of applications
and manufacturers) in order to fully activate all inherent benefits. However, it is not sufficient
that systems merely provide all functionalities, but they must also become usable for nonprofessionals
in everyday life. This ultimately calls for two qualifications. First, installation, setup, configuration, and
maintenance of a HAS should come near the famous “plug and play” paradigm and configure itself automatically
as far as possible (e.g., zero-configuration networking). Especially, no technician or engineer
should be needed to successfully install and use the system. Additionally, integrating any existing equipment
of homes (i.e., in case of refurbishment or extension) should get by with a minimum of physical intervention.
Second, the system must be usable for the residents during regular operation. This demands
© 2011 by Taylor and Francis Group, LLC