Architectural Lighting Controls In Building
Helsinki Metropolia University of Applied Sciences
Degree: Bachelor of Engineering
Degree Programme: Electrical Engineering
Thesis: Architectural Lighting Controls In Building Automation Systems
Number of Pages
Timo Ruohomäki (firstname.lastname@example.org)
Architectural Lighting Controls in Building Automation Systems
8 June 2015
Bachelor of Engineering
Tapio Kallasjoki, Senior Lecturer, Metropolia UAS
Building Automation Systems (BAS) are being deployed in commercial and public
buildings to enable monitoring and control of various intelligent systems like HVAC, fire
safety, security and lighting systems. Lighting is nowadays an integral part of BAS due to
the constantly evolving central control requirements. The BAS is also a key tool in
monitoring the energy consumption and processes that have affect on the use of energy.
The thesis presents an introduction to key technologies and designs within the field of
building automation when lighting controls are involved. Some reference installations are
presented to give an idea about the user requirements and challenges faced in real
projects. Based on the study of example cases, a proposal is made of a building
automation system architecture that would better suit projects where the requirements are
Architectural lighting, dynamic lighting, architainment,
building automation, control system, lighting control, KNX,
Timo Ruohomäki (email@example.com)
Arkkitehtuurivalaistuksen ohjaus kiinteistöautomaatio-
Tapio Kallasjoki, lehtori
Kiinteistöjen talotekniset järjestelmät ovat yhä useammin integroituja ja yhteisen ohjauksen
hallitsemia. Kiinteistöautomaatiojärjestelmiin on liitetty erillisiä valvomo-ohjelmistoja, joiden
avulla pyritään seuraamaan ja ohjaamaan LVI-järjestelmien, sähköautomaation,
paloilmaisinten sekä turvallisuusjärjestelmien toimintaa. Viime aikoina
kiinteistöautomaation tehtäviin on yhä vahvemmin tullut myös kiinteistön
Tämän työn tarkoituksena on tarjota katsaus sekä arkkitehtuurivalaistuksen aiheuttamiin
toiminnallisiin tarpeisiin että ohjausjärjestelmien ominaisuuksiin. Työssä esitellään myös
menetelmä ohjausjärjestelmien toiminnallisuuden varmistamiseen ja vaatimusmäärittely
järjestelmälle, jonka avulla kehittyneetkin valaistusohjaukset ovat mahdollisia.
Arkkitehtuurivalaistus, dynaaminen valaistus,
valaistusohjaus, kiinteistöautomaatio, sähköautomaatio
1 Introduction 1
2 Background 3
2.1 Introduction To Architectural Lighting 3
2.2 Controlling Lighting Levels 7
2.3 Architainment Lighting 10
2.4 Introduction to Lighting Control 15
2.5 HMIs, DCS And SCADA Control Systems 19
3 Control Systems for Building Automation 21
4 Lighting Control Protocols 26
4.1 DALI 26
4.2 KNX 27
4.3 DMX512 28
4.4 DC (0-10 volts) 29
4.5 Summary 31
5 Method for Testing A Lighting Control System 32
5.1 Introduction 32
5.2 Methods 32
5.3 Results 34
5.4 Conclusions 36
6 User Requirements 37
6.1 About User Requirements 37
6.2 End Users 37
6.2.1 Ordinary People 37
6.2.2 Technical Staff 38
6.3 Lighting Designers 39
6.4 Electrical Design Engineers 39
6.5 Contractors 40
6.5.1 Tender Process 40
6.5.2 Project Delivery 41
6.6 IT Department 41
6.6.1 Security 41
6.6.2 Backups 42
6.6.3 Virus Protection 42
6.6.4 Disaster Recovery 42
6.6.5 Virtualization 42
6.6.6 Network Access and Firewalls 43
6.7 Maintenance 43
6.7.1 Facilities Management 43
6.7.2 Electronic Building Manual 44
6.7.3 Helpdesk 44
6.7.4 Accurate System Time 45
6.8 Energy Saving Regulations 45
7 Functional Requirements for Building Automation System 47
7.1 Introduction 47
7.2 System Architecture 47
7.3 User Roles 47
7.4 Availability 47
7.5 Usability 48
7.6 Security 48
7.6.1 Physical Security 48
7.6.2 Information Security 49
7.7 Connectivity 49
7.8 Commissioning 49
7.9 Maintenance 49
8 Conclusions 51
Abbreviations and Terms
BAS Building Automation System is a control system that can be used to
monitor and manage the mechanical, electrical and electromechanical
systems in a facility.
Ballast A device for operating lamp sources such as HIDs and fluorescents that
use an electric discharge or arc. The ballast provides the necessary
voltage, current, and waveform for starting and operating these lamps.
BMS Building Management System is a synonym to Building Automation
CRI Colour Rendering Index is a measure of light source’s ability to show
object colours ‘naturally’ or ‘realistically’ compared to a familiar reference
source, such as incandescent light or daylight
DALI Digital Addressable Lighting Interface is a network –based system that
controls lightning in building automation. DALI is an open standard
specified in IEC 60929 and IEC 62386. (See Chapter 4.1)
DCS Distributed Control System, a supervisory control system that typically
controls and monitors set points to sub-controllers distributed
geographically throughout a factory
DMX512 Digital Multiplex is a standard for digital communication networks that are
commonly used to control stage lighting and effect. (See Chapter 4.3)
DSI Digital Serial Interface is a protocol for controlling lighting created by
Tridonic in 1991. The DALI –standard is based on DSI.
Glare The effect of overly bright luminance within the normal field of view,
sufficient to cause annoyance, discomfort, or loss of visual performance.
HID High-intensity discharge, generic term describing electric discharge lamp
technologies that typically utilizes short arcs and high wattages. HID
technologies include metal halide, mercury vapour and high-pressure
HMI Human-machine interface, the hardware or software through which an
operator interacts with a controller. An HMI can range from a physical
control panel with buttons and indicator lights to an industrial PC with a
colour graphics display running dedicated HMI software.
HVAC Heating, ventilation and air conditioning is the technology of indoor and
vehicular environmental comfort. Its goal is to provide thermal comfort
and acceptable indoor air quality.
KNX A standard for home and building control (See chapter 4.2)
LAN Local Area Network, a network of computers on a relatively small area
that share the same physical connection infrastructure
Luminaire A complete lighting unit or fixture consisting of the lamp source, the lamp
holder, any reflector or lenses to control the light, any shielding to control
the glare, and a connection to a power source. It also includes all
accessories and control gear considered part of the final unit.
NTP Network Time Protocol is a protocol used for synchronizing computer
clock times within a network. The origin of the time can be a GPS signal
or an atomic clock.
PLC Programmable logic controller, a small industrial computer used in
factories originally designed to replace relay logic of a process control
system and has evolved into a controller having the functionality of a
SCADA Supervisory control and data acquisition, similar to DCS with an exception
of sub-control systems being geographically dispersed over larger areas
and accessed using remote terminal servers.
Scene A specific setup where groups of lights are on, off and/or dimmed to
accommodate a specific aesthetic, functional, and/or task requirement.
WAN Wide Area Network, a network that spans wider than a LAN, consisting of
two or more LANs connected to each other via telephone lines, other
networked connections or very large area networks, such as the Internet.
In a commentary published at the Architectural Lighting online magazine, Elizabeth
Donoff gives some insights on the distinction between architectural lighting design and
lighting design in general. Her view is that “architectural lighting is an act of crafting
space – exterior and interior – with light. This is illumination done in concert with
architecture. Architectural lighting is also meant to last for a substantial period of time
unlike, for example, theatrical lighting, which is created for a specific performance and
exists only for the duration of its run.”. [1, 13] Architectural lighting and common interior
lighting should however share the same technical infrastructure, cabling and controls. It
is important that the lighting scenes designed to emphasize the architectural structures
are controlled by the same system that is capable of controlling all the lighting fixtures
within the space or building.
Building Automation Systems (BAS) provide automatic control of the conditions of
indoor environments. It is a network of integrated components that manage a number
of sensors and actuators within the building. The systems typically control HVAC,
security/access control, lighting, energy management, maintenance management and
fire safety. A Human-Machine Interface (HMI) is provided to give maintenance
personnel a single view and control access to all technical facilities and tools to monitor
This thesis work focuses on the benefits and issues identified when the building
automation system also acts as a controller for the architectural lighting. The work is
based on interviews of lighting designers, contractors and facility management. The
work was also influenced on my own experiences at the Helsinki Music Centre, which
at the time of its opening was one of the largest KNX installations in the world.
The control systems have some technical features that – perhaps unnecessarily – limit
the options lighting designer and operations staff have available for their daily work.
The systems are designed to act independently without any other than pre-
programmed operator intervention. The controls are typically simple on/off controls of
groups of lights and sometimes call for specific scenes that were defined on early
stages of the building’s electrical design. In reality the needs evolve, designs have
issues and rooms are used in a different way than originally planned.
The thesis work is structured as five major sections:
• Introduction and description of the key concepts related to the subject
• Introducing a testing method for lighting control systems
• Study of user requirements and technical feasibility
• Functional requirements for a building management system
The introduction provides definition for the core concepts of the work: what is
architectural lighting and what are the building automation systems.
The study of requirements and technical feasibility is based on interviews of users with
different roles and my own experiences. The user input is analysed and interpreted into
role-based use cases. Of the use cases some key functional requirements are then
defined. The information together could be used in product development or when
evaluating existing control system products for a new project.
In larger projects the data transfer capacity of control system field bus can become an
issue. In this thesis I have developed a simple test method that can be used in a larger
scale to verify that the design is doable. The test can also be used to study interfaces
with external real-time controls and identify the bottlenecks in the system. These
results highlight the importance of careful planning of the topology of the automation
The functional requirements are derived from the user interviews conducted for this
thesis work. The functional requirements form a basis for specifications of a building
automation system that would better support the current and upcoming requirements of
The final section is conclusion and recommendations. The comments and
requirements from users with different roles are summarized and some
recommendations are formulated for the future projects.
2.1 Introduction To Architectural Lighting
Hervé Descottes, the founder of New York –based lighting consulting firm
L’Observatoire International, has narrowed down his approach to architectural lighting
design in six visual parameters [2, 13]:
• Colour and Temperature
• Direction and Distribution
All the parameters are linked to functional requirements of the lighting control system
and the selection of lighting fixtures. However, too often the lighting design simply has
the goal of providing an even illuminance level throughout the space.
Illuminance simply describes the amount of light emitted by a light source that lands
on a given surface area. In architectural lighting, the illuminance brings shape and
clarity to a nuanced spatial composition. With careful planning the intensity of visual
extremes can be controlled. Illuminance provides visibility; light and vision are required
to sense distances and depth, colours and contrasts, volumes and textures.
In architectural environments the absence of light is also a powerful tool. Some
functions such as movie theatres and concert venues require darkness or very low
illuminance levels. When the building has such functions, a person entering the
building would better adapt to darkness by going through zones that gradually
decrease the illuminance.
Luminance quantifies the intensity of emitted light from a given surface. Luminance
ratios describe the difference in brightness between two objects or areas in a given
environment. A careful planning of luminance levels gives the designer a tool to
manage the sense of hierarchy and direction. The luminance contrast can reveal or
hide a form. It can manipulate person’s perception of depth and the reading of space.
Altering bright and dark can guide people’s eyes while also signalling places of
importance. Glare control is also a vital part of managing luminance contrast.
The colour and colour temperature of light are linked to the perception of space and
time. They are important factors when setting a certain mood for the space.
The colour temperature however does not address the ways how light renders colours.
The spectral energy distribution illustrates the light source’s capacity of producing an
even energy at all the wavelengths. In order to make comparison of light sources
easier, a rating system called colour rendering index (CRI) has been developed. It has
values from 1 to 100 and as a rule of thumb, sources with CRI of higher than 80 make
subjects look more natural.
The colour in lighting design has a role in contributing identity and orientation to place.
Coloured light leaves a long-lasting impression of a place because we tend to
remember our experiences by the colour in which they were rendered. The controlled
use of light colours can also intensify the experience of an environment or induce
emotion. It should however be noticed that the choice of colour is a personal
preference, resulting on a subjective experience. Use of coloured light can be a quick
fix to change the mood of otherwise plain space into something more comfortable.
The selection over natural and artificial light is related to the colour of light. Over the
course of day, the sunlight has all the hues from red to white to blue. For humans and
animals the quality of skylight tells the time of day and month of year. In interior lighting
it is often effective to vary the colour, hue and saturation of light in a similar fashion.
Incandescent lights with low temperatures can mimic the light of the setting sun.
Fluorescent lights on the other hand come in various types and can be used to create
the sensation of ambient light. The latest LED drivers and lights can produce any
combination of light output and colour temperature at any given time. Managing all the
options available at the building level is yet another challenge for the automation
According to Descottes, the spatial relationship between a light source, the ground
plane, the ceiling plane and our bodies determine how we understand, occupy, and
explore the limits of our surroundings [2, 52]. The height at which the light sources are
installed is thus an elemental aspect of architectural lighting design. At a great distance
a light fixture may go unnoticed while in a bodily proximity, it can become a reference
point. Height is capable of provoking a sense of expanded space or visual intimacy.
Density controls the movement and rhythm of space through the quantity and spatial
composition of light sources. The intersection and overlays of architectural and
luminary patterns can create unexpected counterpoints, combinations of form and light
that guide a visitor. The density consists of two parameters: the number of fixtures on
certain area and the organizational character of grouping of the fixtures. The
organizational character can be categorized into three types: linear, random and
organized. In linear organization, the grouping of fixtures aims at a single, linear light.
In random organization the positioning of fixtures don’t follow any geometric logic. In
organized positioning the placement of fixtures follows a geometric logic and all
together they form a certain recognizable shape or pattern.
With direction and distribution the light beam gets a concrete form. A narrow beam
can cut through a space to highlight a specific area while a wide beam can illuminate a
larger area. In general, the distribution of light is either concentrated when the light is
focused or diffuse, when the light is dispersed over wider area.
The direction and distribution of light offer the following options [2, 71]:
• An indirect-diffuse uplight will illuminate the ceiling, drawing our eyes to upper
limits of the space
• A direct-diffuse downlight will illuminate the floor or other plane in the room,
making it the prominent surface. An illuminated floor will visually ground the
visitor in the space
• An indirect-concentrated uplight will create an area of high luminance on the
• A direct-concentrated downlight will create an area of high luminance on the
floor and high contrasts within the space
• A multidirectional-concentrated light source will offer up non-uniform brightness
in the space, calling the viewer’s attention to specific, highlighted areas
• A multidirectional-diffuse light will evenly illuminate various surfaces in a space,
minimizing contrasts and the presence of shadows
It is important to notice that the options described above may change during the day:
the space is used in a different way during the daytime, evening and night. In buildings
with large glass facades the used interior lighting scene is also visible from outside the
building, raising the significance of careful planning of the night-time scenes. An
interesting example of this approach is presented later in chapter 2.2.
Table 1 illustrates how the six parameters described above were drafted for the Kiasma
Museum of Contemporary Art project (original lighting design 1998 by L’Observatoire
Table 1 Kiasma Lighting Plan
Top of wall:
In the case of Kiasma, the architect Steven Holl requested all of the lighting fixtures
being removable or concealed. The halogen lights provided a concentrated beam of
light that illuminates each artwork with specific purpose. The light must not contain any
ultraviolet component. The accent lights are separately dimmable and their CRI is
The following image of Kiasma illustrates the effect of different colour temperatures and
direction of interior lighting when observed from the outside of the building:
Figure 1: Kiasma
© Benoit Peverelli, 1998
Of this information and by gathering more requirements from the end users the design
engineer would start to plan on how to program the lighting control system, what kind of
lighting scene presets would be required and what parameters should be left to be
adjusted by the user. Another challenge is that the link between a programmed
dimming level value in the lighting control system and the actual light output is not
2.2 Controlling Lighting Levels
Especially when using fluorescent lamps, central control of dimming can be
complicated. As an example, while we know that in a certain space the illuminance at
full level should be 1000lx, setting the ballast dimming value to 25% would hardly result
as illuminance level being exactly or even around 250lx.
The chart in Figure 1 illustrates the issues related to dimming fluorescent T8 lamps with
voltage-controlled ballasts [3, 19]:
Figure 2: Dimming Ballast Study: Light Output
The chart shows that there are significant differences between products of different
vendors on how linear the dimming actually is. If the ballast is set to dim down to 20%
(i.e. provide 2 Volts as control signal), the actual light output of the lamp would be from
8% to 22% depending of the ballast. If we further assume that the full power output
would result as 500lx of illuminance level, dimming the light down to 20% would
actually result as illuminance level being somewhere between 40 – 120 lx depending
on the chosen ballast. Whether this is an issue or not depends on the lighting design
and the role a combination of different fixture types has in it. It may become an issue if
ballasts from different vendors are used in the same space which often is the case,
since the ballasts are included in the lighting fixture. It may also become an issue in
projects where dimmed lighting scenes have a significant role, e.g. in restaurants or
Another interesting finding in this study is that the the lamp might still be on while the
control signal is 0 Volts. In order to fix this and allow smooth dimming from full to black,
some ballasts have a programmable parameter to set the threshold of control voltage
where the light output is full and when it cuts off. Checking these values is mandatory
when the smooth, centrally controlled dimming function is critical, which is the case in
cinemas, concert halls and theatres. For the contractor it requires a significant effort to
manually go through these parameters on every single ballast – there might be
thousands of ballasts installed in a single installation. It would be preferred to have a
central management tool to re-configure ballasts if necessary.
The same variance can be seen in the diagram at Figure 3 when comparing the control
voltage levels with the power consumption of the ballast:
Figure 3: Dimming Ballast Study: Power Consumption
Again we can see a significant variance between products in how linearly their power
intake follows the control voltage. When planning to use dimming as a method to
conserve energy, dimming the ballasts down to 80% level would not generate any
savings when using ballasts manufactured by Company B.
In practise this means that in order to meet the planned illuminance levels, there should
be an option to manually adjust the pre-sets according to the actual, measured light
output. This is mandatory especially when the illuminance contrast is an essential
element of the lighting design. Naturally this adjustment is part of the maintenance
routines, since the lamps and ballasts may well be replaced with another types and
their light output and dimming characteristics will be different. The light output of lamp
will also decrease over the time due to its ageing and a calibration of the programmed
scenes might be required.
2.3 Architainment Lighting
Architainment lighting is a combination of architectural and entertainment lighting. It
aims to provide an experience for observers, breathe life into buildings and highlight
their architectural features.
Architainment lighting typically involves intense coloured lighting effects and shapes
over large areas. The controls go beyond switching between pre-programmed scenes.
The transition from scene to another one must be smooth and controlled when the
colours are involved. The motion of projected shapes can also be part of the design.
The fixtures used in architainment lighting have become very powerful tools for a
lighting designer. An example of a product used in exterior lighting installations is the
Martin Exterior 400 Image Projector illustrated in figure 4. It provides a light output of
7000 lumens. The light beam can be modified with six customisable gobos and eight
custom colours. For the gobos there is focus control. The device can be safely installed
outdoors because it has an IP65 –compliant housing. The control system will manage
the fixture using nine DMX512 –channels.
Figure 4 Martin Exterior 400 Image Projector
© Martin Professional A/S, 2014
Architainment lighting is integrated with the activities happening in the building, thus
requiring a control system that can be programmed beforehand but also can be directly
controlled if there are needs for sudden changes. As an example, a conference center
may hold an event where the organizing company uses orange as a brand colour in
their marketing. It would be expected that the same colour is somehow visible in the
lighting to highlight their brand. When the event finishes at 23:00, the colours should be
switched back to normal.
The following examples of interior lighting having architainment characteristics and
being linked to activities of the building are from a design proposal made for the new
New York Sports and Convention Center in 2006. The architect was Kohn Pedersen
Fox and the lighting designer L’Observatoire International from New York. The project
manager and senior designer for lighting in this proposal was Beatrice Witzgall.
The lighting design is based on an idea that the building has three ‘modes’: an idle
mode, a convention mode and a sports event mode. The following render images
illustrate the differences between the modes.
Figure 5: NY Sports and Convention Center in Idle Mode
In Figure 5, the orange light in the base of the building causes the glass facade to
appear to float, and no direct light is employed behind so that it reflects the water of the
river. Some exterior lights are directed to the river to emphasize the surface of water.
Figure 6: NY Sports and Convention Center in Convention Mode
In the convention mode in Figure 6, the buildings internal steel structure and the people
are exposed through the glass façade, and the building is visually grounded by its base
and façade lighting.
Figure 7: NY Sports and Convention Center in Game Mode
In the game mode illustrated in Figure 7, the orange colour wash is used as a strong
effect to draw focus on the building. The blue and orange colours are also the brand
colours of the New York Islanders hockey team. The skylight provides a strong effect
turning the building into a landmark.
Internally, the direction of lights has a significant meaning: vertical downlight does not
cast shadows or reveal the internal structures but provides the orange wash. In active
modes the lighting has more horizontal direction, revealing the internal steel structures
and projecting shadows.
The following Figure 8 illustrates the lighting directions and beam angles in the
Figure 8: Lighting Directions
The concept of three modes is somewhat simple to accomplish with the lighting control
system. An integration with the house booking system would be ideal. However, when
the design is based on an expectation that there is no other light sources or leakages
of light inside the building, then the whole setup requires a complete control over both
the interior and exterior lighting. This case is also a good example to illustrate the point
why effect or theatrical lighting control also needs to have some level of integration with
the interior lighting control: the control is required to make sure manually controlled
interior lighting or occupancy recognition does not spoil the desired effect.
2.4 Introduction to Lighting Control
Craig DiLouie defines the main functions of lighting control as follows [4, 3]:
• on/off switching
• occupancy recognition
• task tuning
• daylight harvesting
• lumen deprecation compensation
• demand control
On/off switching is the simplest form of control and it is a manual control method.
Even if there is no lighting control system and the switching is done with a manual wall
switch, the transition from on-scene to off-scene does not need to look sudden and
harsh. Some ballasts and LED-drivers can be programmed to do switching off with a
smooth fade. The ballasts can also be programmed to run only at i.e. 80% of
brightness when switched on if there is a need to limit the light output and thus
conserve energy. While this is all possible, the programming in practise is done by
plugging every ballast separately in laptop computer with programming software. If
there are hundreds or thousands of ballasts and their control bus is not wired, this
would not be an option. According to calculations provided by General Electric, a
warehouse where lights are dimmed down to 60% on 85% of the time could annually
save 34% of its total electrical energy consumption .
Occupancy recognition is used in intermittently occupied areas or rooms, typically to
turn on lights when people are present and off automatically after a certain time when
they are no longer present. The presence information can also be used together with
room scheduling systems to provide real-time information on whether there is actually
anyone present in a booked room. If not the booking can be released and given to
another user. This approach can significantly improve the level how the meeting rooms
When scheduling is applied, electric illumination in given areas is activated,
extinguished or adjusted according to a predetermined schedule. There can be
several, overlapping operating modes. Scheduling is a time-based function and is best
suited for facilities where certain activities always happen at certain times. Since
schedules always have exceptions, some local button panels with override methods
need to be considered.
Figure 9 Sample lighting schedule
Tuning means adjusting the light output of a lighting fixture or a group of lights to the
specific level needed for the task or other purpose, such as aesthetics. It is most
commonly done through dimming. It can also be accomplished through switching, as
when ballasts are wired in a way that while only part of the luminaires are set on an
even light flow is provided throughout the space. Tuning can also be used together with
occupancy recognition in a way that the light level is increased when the person enters
Daylight harvesting is applied when daylight entering a space can’t be put to positive
use. The systems involved use strategically located photocells to determine the
ambient light level. This information is fed to a control device that then raise or lower
luminaire output or turns off selected luminaires to maintain the amount of light set for
the space. The adjustment is constant and the persons in the space are not aware of it.
Both the DALI and KNX systems have components for shutter and blinds control that
can be used together with dimming to achieve natural and comfortable level of lighting.
Demand control is related to efforts to conserve energy. In short, demand control can
be achieved by installing an infrared sensor that switches the light on when the person
enters the room and switches it off after he leaves. In spaces like toilets or storage
rooms this approach can save the majority of the energy when compared to traditional
switches that tend to be left on on-position.
In the past it was adequate to monitor the energy consumption of the whole building
and perhaps invest on equipment with lower power requirements. Nowadays the
requirements to monitor energy consumption are more specific and the systems should
provide tools to identify the exact space or function that consumes energy more than
average. This can be achieved e.g. with advanced relays that have a built-in current
sensor. A certain type of digital ballast can also provide information of its current power
consumption. In theory, the building automation system could then monitor energy
consumption at a device-level. In practise this has proved to be challenging due to the
limited data transmission capacity of field bus networks.
A recent research has added one interesting function to the list: dynamic lighting. The
goal is to mimic the natural rhythm of night and day that our bodies respond to. By
positively affecting the human biological clock, wellbeing is stimulated and the person
kept alert and refreshed.
The dynamic lighting concept is based on lighting scenes that combine the control of
both light intensity and colour temperature. The recent research indicates that the light
qualities of illumination and colour temperature might influence student gains in
Dynamic lighting is typically based on technology where LED lights of different colour
temperature are mixed and the ratio on which each type is driven defines what is the
colour temperature of total light output. Helvar provides a specific ‘Tunable White’ two
channel LED driver product for such cases. When drivers like these are used, the
lighting control system must know how to manage the mixture of these two channels to
provide desired output. It is also important to calibrate the presets so that each lamp
provide the same color temperature since variance looks unprofessional especially on
long light strip type of fixtures. This calibration process might require a re-do after a
couple of years of use.
Figure 10 Helvar Tunable White LED Driver
In some designs, the lighting design concept also includes control of motion. As an
example, the position of a lamp may be automatically adjusted according to a plan. The
Figure 11 is taken from the Finnair Lounge of Helsinki Airport, where Finnish lighting
technology company Alumen Ltd provided the complete lighting setup according to the
plan of architect Vertti Kivi. In this case the round lamps slowly move up and down
creating a dynamic yet calm effect. In this example the motion control is managed with
an AV control system, but it could also be done with a simple PLC or industrial motion
controller system that the lighting control system would drive with 0-10 VDC control
Figure 11: Finnair Lounge at the Helsinki Airport
© Alumen Ltd, 2011
2.5 HMIs, DCS And SCADA Control Systems
While the control systems are getting more complex and have more capacity, the
usability requirements for the management stations have increased as well. A large
building may have tens of thousands of sensor points and actuator channels managed
by the automation system and it is a challenging task to provide a central point of view
to monitor it all.
The Human-Machine Interface (HMI) is a software application running on a PC or an
embedded hardware that presents user information about the state of a process and
provides user control functions to manipulate the process. Typically the information is
displayed in a graphic format (Graphical User Interface, GUI). Human-Machine
Interface can also display alerts and notifications.
The Distributed Control Systems (DCS) are typically real-time, fault-tolerant systems
for continuous and complex pre-programmed applications. Initially the DCS systems
were designed for continuous processes that were controlled by actions triggered in a
loop or sequence. A DCS system typically communicates via a low-speed yet reliable
Supervisory Control and Data Acquisition Systems (SCADA) are typically computer-
based systems that are capable of gathering and processing data and applying
operational controls over distance. SCADA systems are designed to manage delays
and data integrity issues over communications. They also can connect to the actual
automation networks using a variety of media, including the Internet, phone lines, radio
transmissions and so on.
All three functions can be identified on a typical building automation system. The
topmost HMI –layer can be a stand-alone or client-server system built on top of some
graphical user interface development toolkit. There can be several different HMI’s in
the same building. There can be wall-mounted touchscreens for local room control, a
user interface for specific controls installed on smartphones and then a control room
that provides a view and access to all HVAC and electrical systems in the building.
Figure 12 illustrates the main parts of the building automation system with generic
terms used in industrial automation.
Figure 12 Main functions of the automation system
To provide the actual control functions, building automation systems oftentimes have
both DCS and SCADA characteristics. The SCADA –part takes care of system-wide
controls such as scheduled control events. The DCS modules are part of the
automation system that acts as independent nodes within the KNX or DALI networks.
The nodes are separately programmed and maintain the instructions in their internal
memory to react on control messages and to provide control functions as required.
3 Control Systems for Building Automation
The building automation system is typically a combination of several subsystems that
are based on different technologies. Because of this, various interfaces are required in
interchange information between the subsystems. This also brings the elements of IT
network topology design into projects, since the designer have to carefully design the
system architecture to balance traffic on all the branches to avoid bottlenecks and to
maintain acceptable security. Figure 13 provides an example of a building automation
system that covers the control of HVAC, lighting and access control.
Figure 13 Building Automation System
In this example, the ‘backbone’ of the network would be a standard Ethernet network.
The subsystems would connect it with router interfaces that allow transferring KNX or
DALI messages over Ethernet to the control system server.
Lately an increasing number of vendors have been introducing Ethernet control ports
into their products as part of their Internet-of-Things (IoT) -concepts. This will make it
easier to build very large systems but also make central control and monitoring
possible. Traditional ICT –companies like Cisco Systems have also entered in the
market with IP-based products, in their case products for door access control.
The market for building automation systems is significant. According to report from
Navigant Research, the global revenue of building automation systems is currently
about $59,3 billion and is expected to grow to $86,7 billion in the next ten years .
The growth in the BAS market is primarily a result of energy code requirements, energy
expenditure reductions and green building certifications.
The building automation systems market can be divided into the following segments:
• HVAC Controls
• Security & Access Controls
• Lighting Controls
• Entertainment Controls
Of these, the HVAC controls have been dominating the market. Most of the systems in
the market have originally been developed for controlling HVAC and depend on
integrations when used for controlling lighting or security & access. Regarding the
HMIs this shows in the features of their user interfaces: while in HVAC controls the
whole system is presented as a process chart, in lighting controls it is more important
to locate objects that have a single function from a floor plan according to their physical
Aside of the BMS market, a new market segment has been created for the Building
Energy Management Systems (BEMS). While monitoring the energy efficiency is a
common feature on BMS systems, their limitations and new requirements to visualize
the energy consumption trends have been driving to use yet another system for those
needs. The global revenue of BEMS –systems is expected to reach $2,4 billion in 2014
and to grow to $10,8 billion by 2024. 
The BMS market is lead by the following companies:
• Johnson Controls
• Schneider Electric
• United Technologies Corp.
Of these companies, Schneider Electric and Siemens have also a strong product
portfolio of KNX control modules. The Siemens Desigo Insight and Honeywell
WebVision have been used as HMIs for lighting control but feature-wise do not offer
the flexibility and usability expected by the users. Since many of the BMS products
were originally developed for controlling HVAC –systems, the primary user interface
displays the system as a circuit diagram, similar to the riser diagrams used in electrical
system design. This approach works fine as long as there are up to tens of objects on a
single screen. Also, in a typical HVAC system the ‘objects’ are large units that could
contain internally a number of components and still are performing a single task:
cooling air, pumping water or controlling airflow. In the case of lighting control, a similar
‘object’ could be ballast, infrared detector or LED driver. There could be thousands of
them in a single building and any of them could be the target of control or monitor
operations of the user. If the system is illustrated in the form of a single-line diagram,
there would still be the issue of the operator being able to associate a symbol in a
diagram with its physical location in the building and vice versa.
Figure 14: Screen capture of Siemens Desigo Insight user interface with Process Viewer
© Siemens AG, 2011
Some HMI –systems provide an option to illustrate the system also in a form of
standard single-line diagram. When choosing the system attention should be paid on
whether the additional viewer modules provide the same control functions: they might
be only viewers and not provide any actual control options for the objects displayed in
the screen. A user familiar with other Windows software applications have expectations
on when seeing an object on a Window, clicking or right-clicking it would provide some
functions. Also the user would expect that when an object has the colour of red, it
provides a warning and when it is green, it functions correctly.
Ideally the lighting system objects are the easiest to locate when displayed over a floor
plan. In a large building the floor plan view should also be scalable and able to display
only part of the building. Different colours in the display make it easy to define control
areas and to identify point requiring immediate attention. The icons of controllable
objects should be carefully considered in order to provide a quick view on the status on
larger area. As an example, the operator would need to know whether the lights on
certain space are currently controlled manually, by timer or by presence indicator, since
the operating mode may change during the day.
Figure 15: HMI User Interface
Setpoint Building Automation, Inc.
Design of the user interfaces is a significant task when commissioning a HMI for a
building automation system. Even if the floor plans are available in AutoCAD or other
file format, it may be easier to just redraw the wall lines using the development tools
provided by the automation system vendor. The data model files such as IFC should
make this process easier, but currently there are hardly any HMIs that could do that.
4 Lighting Control Protocols
Digital Addressable Lighting Interface (DALI) is part of the IEC standard 929. It
provides communication rules for lighting components. It was first developed in the mid
‘90s, with commercial applications begun in 1998. In Europe, ballast manufacturers
including Osram, Philips, Tridonic and Helvar have adopted DALI as a standard
interface on their products. It has rapidly replaced the 0-10VDC and DSI control inputs
on ballasts. DALI aims to provide a vehicle for manufacturers, facility managers and
contractors to have confidence that products from multiple manufacturers will be
compatible and interoperable. 
According to the DALI –standard, there can be up to 64 controlled devices in a single
system. The devices can be assigned into 16 groups to create logical entities. Larger
systems can be created by using DALI –routers that route the control messages
between DALI –systems over the TCP/IP –network. With this approach, the largest
installation made so far had 32.640 controlled devices and over 600 routers.
A DALI –based lighting system is commissioned using software provided by the vendor
of ballasts and control panels. There are some options to modify lighting scenes on
runtime using the switch panels. There may be slight interoperability issues with
devices from different vendors so in general it is better to design the whole system from
components from the same manufacturer. The commissioning software for most Helvar
Dali -products is called Digidim Toolbox and it can be downloaded for free from the
Helvar website. More advanced devices such as Imagine routers require another setup
software called Designer that is only available for certified users. Some Imagine -
interface products cannot be used as part of a Digidim –setup if it doesn’t have a router
so knowing the components is important in order to successfully provide a complete
The DALI –products are mostly intended for purposes close to lighting control. DALI is
available in ballasts, relays, blinds/shutter control modules and general purpose
dimmers. The wall switches also connect directly to the DALI –bus. The system can
also include a router that would make it easier to interface with IP –based controls or
The DALI –standard is currently being upgraded. The new DALI 2 –standard will
introduce new types of devices. External controlling is also improved by introducing
application controllers in both single master and multi master modes. By design, the
DALI 2 –standard will be backwards compatible. It is expected that the last publications
related to new DALI 2 design features are expected to be published in 2016-2017. For
some vendors like Helvar the new features are not seen as important, since they have
already figured out the ways to control Dali networks despite of the limitations of the
current standard version. This may have caused some issues with interoperability
between products of different vendors so the new DALI 2 may improve the situation in
KNX is a standardized (EN 50090, ISO/IEC 14543) network communications protocol
for intelligent buildings. KNX has evolved from three earlier building automation
protocols, the EHS (European Home Systems Protocol), BatiBUS and the EIB
(European Installation Bus). The KNX standard is administered by the KNX
Association. The association certifies equipment that are allowed to connect to KNX
bus. Persons interested in working with KNX systems usually have attended training
sessions and acquired certifications provided by the organization.
In the KNX –system the logical connection between input (=sensor) and output
(=actuator) is defined with a Group Object. A suitable data type can be chosen from a
selection to provide the control information from sensor to actuator. As an example,
the data type can be a 1-bit on/off command or a text value that displays the current
reading of an energy meter in kWh -values. When a KNX –system is controlled from
outside, the external system would read or write into the group objects directly, acting
as a ‘sensor’. With this approach the external control system can be safely replaced
with another system without any need to change any KNX –programming.
The KNX –products are used for various purposes:
• Lighting control
• Heating/ventilation and air conditioning control
• Shutter/blind control
• Alarm monitoring
• Energy management and metering
Currently there are over 370 vendors providing KNX-certified products. The total
number of products is over 7.000. Some well-known vendors are ABB, Schneider,
Siemens and Hager.
The KNX system is commissioned using ETS –software developed by the KNX
Association. The current version of the software is ETS5. The software is also used to
provide documentation of the installation. The ETS –software is modular and can be
extended with new device libraries and device-specific extensions. This is mandatory
since the functionality of devices in a KNX –system can be very complicated and their
setup requires more than just entering some property values. Recently, the software
tools for commissioning have fragmented a bit due to vendors desires to implement
features that are more complicated to provide as a plugin for ETS software. For the
commissioning engineer this has meant a less smooth workflow: as an example, a
sensor inputs need to be activated in a different software and then programmed in the
ETS. In some cases the vendors have released utility software products of which the
added value is hard to recognize.
DMX512 is a standard for controlling light on live performances. It is a multiplexed
digital lighting-control protocol originally designed for up to 512 dimmer channels. It
was developed by the United States Institute for Theatre Technology (USITT) in the
mid-1980s. The main contributors for its development in the beginning were Production
Arts Lighting and Strand Lighting.
DMX512 is electronically based on the EIA RS-485 standard widely used in computing
and automation systems. A link can accommodate up to 32 receivers. The connectors
have five pins, three of them used for a single DMX link and the remaining two for a
reverse link. The reverse link could be used to send dimmer diagnostics information
back to a console. [9, 62-65]
The link capacity of 512 signal channels has in the recent years become a limitation
due to the developments on entertainment lighting. While originally one channel
controlled a dimmer channel of single light nowadays modern light fixtures can
consume even over 50 DMX channels for all their control options. As addition to the
dimming information the console can control colour, colour temperature, XYZ position,
focus, choice of gobo filter and so on. In larger installations this limitation has been
avoided by simply adding more parallel DMX links. One set of 512 channels is called
Universe and control consoles such as the GrandMA2 can provide controls on any
channel on 256 Universes. The communication of such systems is based on protocols
that carry DMX on top of IP protocols so that standard Ethernet networks can be used.
One of such protocols is Streaming ACN (sACN) that can manage up to 32 Universes
on a single Ethernet link.
4.4 DC (0-10 volts)
Along with the advent of easily remote-controllable dimmers came the first of many de
facto dimmer control standards: analogue DC voltage control. The concept is simple:
one wire is run from console to each controlled dimmer and the DC voltage
corresponding to the level of the dimmer is sent down the wire. Zero volts represents
an off condition, 10 volts represents a dimmer output of 100 per cent.
Since every channel requires an own wire, DC voltage control is complicated to
manage when the number of channels is high. A DC signal is also very sensitive on
electrical interference. It requires a multicore cable and multipin connectors and for the
latter there was no widely accepted standard. In Europe the connector has usually
been a 8-pin DIN –connector, in the USA a 10-pin Jones or 36-pin Centronics -
connector. [9, 56]
The DC voltage control has also been widely used with the electronic ballasts for
fluorescent lamps. The dimming control was then a simple potentiometer that adjusted
the control voltage accordingly. In some cases the control voltage range of ballasts is
1-10 volts instead of 0-10 volts which may cause some unexpected behaviour when
dimming down and the room has lamps controlled in different ways.
Table 2 displays the key characteristics of control networks mentioned above. Usually
the speed of the communication link is defined as bitrate, bits per second (bps). When
comparing different data links, this value does not provide a complete answer on
question which bus can deliver the control event fastest due to the different lengths of
control messages. The actual speed –value below defines how many actual control
messages the bus can deliver within a second.
Table 2: Control Network Properties
IP,TP, PL, RF
IP internet protocol (LAN link)
TP twisted pair link
PL powerline, data communication on 230 VAC
RF radio link
In reality, a complete building automation system is a combination of one or more
control systems. In order to reach that, interfaces are required to convert signals from
one standard to another one. Interfaces require careful planning since the speed of
data links is so different and easily causes congestation resulting loss of data.
1 Actual speed is the number of actual device control messages delivered in a second
2 System can be extended to contain multiple DALI –subsystems using router, thus extending the
maximum number of nodes
5 Method for Testing A Lighting Control System
Lighting control is a combination of scheduled and real-time control actions. The larger
the system is, the more likely it is that the slow fieldbus gets congested because of the
sudden flow of control messages. This can be especially problematic when the setup is
based on components with different communication networks that have different data
speeds. In a situation like that, at least two questions need to be asked:
• What happens when traffic from faster network enters in slower network? Will
all the commands get through?
• If the speed of network is X, how many commands in second can we expect the
network to deliver? If we switch all lights on using a broadcast message, will
they actually be lit simultaneously?
• Can we control a lighting system externally with a lighting console? Will we
have smooth fades and reasonable delays?
The answers to the questions are difficult to find from datasheets, especially in systems
where the network is shared with sensors and actuators from various vendors.
A key limitation in large control systems is the capacity of the control network. While
the IP –based networks provide fast access on large number of nodes within the
network, the twisted-pair networks limit the speed down to 9600 or even 1200 bits per
The main goal of the study is to prove that external real-time control is feasible and that
a control system can be based on similar approach.
In order to find out the limits of data transfer capacity a test rig is needed where the
amount of input messages and output signals can be reliably measured in a laboratory.
The test rig should contain modules from both KNX and DALI systems and also an
interface module to convert KNX messages to DALI. With such setup it is possible to
get results for pure KNX and DALI and a hybrid KNX&DALI –systems. These options
will cover the majority of control networks in digital lighting control setups.
A straight-forward method to generate steady flow of control messages into automation
network is to use a module that can convert 0-10 VDC analogue control into digital
signal. To monitor the output, a reverse converter from bus to analogue voltage is
used. With this approach a reproducible test can be arranged by simply feeding signal
in with a signal generator and monitoring it with an oscilloscope. The phase shift or lack
of signal would then tell the point after which the system is no longer capable of
forwarding all the input signals into the output. The following diagram illustrates the test
setup (KNX power supply and USB interface excluded).
Figure 16: Setup for testing control system
The tests are done by using a sine wave with 10 volt amplitude as a test signal. The
oscilloscope is a multichannel type. Its channel A is connected to the signal generator
and channel B to the output of latter D/A converter. The test will start with a frequency
of 0,1 Hz which simulates control event of dimming a light from 100% to 0% and back
in 2,5 seconds. The phase shift measured between original signal (oscilloscope
channel A on figure 16) and the DC output signal (channel B) determines the latency.
The shape of curve provide information on how accurate the analog-to-digital
The test kit was built of the following KNX –modules:
• ABB AE/S 22.214.171.124 Input module
• ABB LR/S 2.2.1 Lighting control module
• ABB USB/S 1.1 USB Programming interface
• ABB SV/S 30.320.5 power supply
In the first test, I studied how the system responds on changes on input voltage that is
full 10 volts. The original signal is drawn in yellow. The following screen capture of
oscilloscope illustrates the results:
Figure 17: Oscilloscope screen capture
The test shows that there is a significant delay on the systems response due to the
built-in parameters of the input device. The device is configured to transmit a value
whenever the input signal changes more than 1%. This does however not seem to be
the case in real life: the output signal starts to grow about two seconds after the input
raised to full 10 volts. The output signal also never reaches the level of the input signal.
In the next test the control signal was provided by a function generator instead of a
power supply. This setup aims to mimic an external lighting control desk, that smoothly
fades light up and down. The frequency was set down to 0,1 Hz in order to provide
natural control. The following oscilloscope screen capture illustrates the results:
The output signal was following the original control with somewhat similar fashion, even
though the shape of the signal was far from smooth and its peaks were lower. When
looking at the raw signal data on using the ETS5 bus monitoring tool, the reason for the
difference became clearer as seen on the following figure:
Figure 18: KNX message data
The data shows that during each ‘fade’, only a couple of measurements are being
made. Even though the device was set to track any change of over 1% and send it to
bus, in reality a measurement was only made once per second. When at the first
measurement the value is 1% and at the second 58% of full value, the fade does not
anymore have any curve and it becomes a linear. This is however a smaller problem
when compared to the finding that the highest value would only be 67-75% of the full
When planning the test setup my expectation was to see the output following the input
with a delay depending on the number of devices active in the network. However the
test showed significant issues in following the shape and level of the original signal.
The results of this study motivate commissioning engineers to test the planned
interface setups with real-life use cases prior to the installation. One simply cannot
expect that while the system can provide a 0..10 VDC input it could be used for any
realtime control operation without careful planning and testing.
6 User Requirements
6.1 About User Requirements
This chapter documents the main themes the interviewed professionals in various roles
relating to the lighting controls had. When implementing the system, it will be helpful to
make sure that the new automation system will answer these requirements.
6.2 End Users
The end users that actually use the lighting systems have various roles that affect on
their expectations and the ways how they use the lighting control system. A control
system designed with usability in mind should be easy to use without any particular
training. In facilities that have specific functions the requirements of end-users should
be studied carefully. It is recommended to categorize the users based on their roles
and study them separately.
During the interviews for this work, a system integrator complained that the typical
planning documents tend to lose the original voice of end-users when the wording of
user requirements is processed into diagrams and charts on early stages of project.
This can be frustrating for both the contractor and end-user when a design matching
with the original requirement could have been provided at the same cost. Especially in
public tenders the communication between the contractor and users is restricted until
the tender is delivered and it is too late to make any changes.
6.2.1 Ordinary People
The ordinary people expect the lighting control system being user-friendly and requiring
little or no effort on daily basis. It is expected that the variance in requirements is
limited and skills to manage special cases like choosing between programmed lighting
scenes in a meeting room can be obtained with little or no training.
When designing controls for ordinary people, it is often recommended to provide
controls with larger scope. It might be possible to merge lighting control functions with
other functions like HVAC controls: Whenever the lights are on, the air conditioning
should also be on.
6.2.2 Technical Staff
The technical staff often has requirements that depend on the function of the facility.
Sometimes AV-technicians need to be capable of managing light leakages on
presentation screens. They are also responsible of temporary setups of showrooms,
confereces and displays of art where the requirements for lighting and control of
lighting are more advanced than in standard spaces.
When planning a project where the requirements are constantly changing and where
special setups are built, the technical staff would require deeper skills on managing the
lighting controls. It should be considered whether the programming software such as
Digidim Toolbox or ETS5 were trained to these types of users.
If the lighting design is based on different modes of the building as in the example of
the NY Sports Stadium, there should be an integration between the house room
scheduling system and the lighting control system to avoid needs to manually re-
schedule the scene changes on the daily basis.
When designing systems that have integrations with AV systems, it should be noticed
that the lifetime of connected devices will be significantly shorter than of the automation
system. A data projector may be replaced within 3-4 years and the next device may
have different control methods than the first one. The cost of re-programming the
automation system can easily be higher than the new device. That causes a risk where
the replaced device will not anymore be integrated and evetually it renders the
automation on that particular space useless.
6.3 Lighting Designers
For lighting designers, the simplicity of programming is a key requirement in the
system. While the design tools are advanced enough to provide detailed programming
guidelines, there is still the need to fine-tune and modify the programming because of
the behaviour of daylight, furniture and possible changes of components of the system.
If the system is too complicated, it may require a skilled programmer to use it and that
would add a significant cost for the implementation phase.
The lighting designers also prefer to work with systems that are specifically aimed at
the market or application they currently work on. This is one reason why special lighting
cases such as lighting artworks or exteriors many times are managed with a system
separated from the house lighting controls. The same applies when using fixtures that
have multiple control channels e.g. for color washing and that typically are DMX512 –
The lighting designers role and expectations also depend on how early in the
architectural design process they get involved. In some cases the architect and lighting
designer may work together from the very beginning, creating the proposal of the
project. At the other extreme are projects where the lighting designer is called to add
‘something cool’ after the building is already completed. In the first case, the lighting
designer can be involved when choosing the control system for lighting, in the second
case there is a risk that the original control system is not flexible enough to support the
vision and the advances features of the fixtures. The outcome will then be having an
another control system working parallel to the original one which is not the preferred
6.4 Electrical Design Engineers
For electrical design engineers, the control systems add a welcomed abstraction layer
that allows the design engineer to focus on the wiring, the positions of control
equipment and leave the programming for later stages – or for a lighting designer to
complete. The flexible wiring topologies make planning and changes easier.
The advanced digital control systems are more challenging to design since their
functionality is advanced and requires experience to manage. A single module in the
system may have many applications to choose from and the exact functions required to
accomplish a certain operation have to be chosen carefully to prevent a situation where
a module needs to be replaced at the construction site.
The electrical design engineers would require a detailed description of the vision the
customer, the architect and the end users have of the lighting setup. The users will
benefit the most of plans that are illustrated as rendered images instead of blueprints or
schematics. DIALux has become a common tool for design engineers to plan the
lighting scenes and to calculate the appropriate illuminance levels on each space. A
detailed description of a type of space in a format of room card is also very useful way
to manage the requirements throughout the planning process.
6.5.1 Tender Process
The contractors prefer using equipment that have reliable delivery times and a small
number of product models to choose from. The products need to be well documented
since in many cases the system will be put together for the first time on site and there
is no time for trying different configurations. It would also be preferred that the products
are simple enough and would not require any special training for the electricians.
The man hours required to set up advanced lighting systems are often hard to estimate
when the programming requirements are vague. There is a significant risk involved with
adjustments like setting the cut-off threshold parameter manually on each of the
ballast: a large installation may have 10.000 ballasts installed, some of them mounted
inside the fixtures. The contractors prepare tenders based on tables of unit costs and
efforts. While it is easy to estimate how many minutes on average it takes to mount and
connect a lighting fixture, the amount required for programming a system with 1.000
ballasts or LED –drivers is hard to base on any fact or experience. The quality of
designs naturally affect on the estimates and risk margins.
6.5.2 Project Delivery
The contractors have a contractual responsibility of delivering a functioning system.
Even though so called hard requirements (e.g. “System must respond within one
second on any control command”) are seldomly used, the contractor still must be
certain that the system works as a whole. The digital control systems have increased
the need to evaluate the planned design in a test setup and this is not a desired
direction for the contractors.
The nature of lighting control systems drives using a two-phase programming: the first
phase is to program the structure to the system, provide addresses to devices and
create sample scene setups in order to test the functionality. The second phase is to
adjust the lighting levels to match with the design, preferably together with the lighting
designer. Very rarely the whole system can be planned so carefully in advance that no
adjustment is required after the installation. Unfortunately, it is also rare that there is
time and resources available to do this kind of fine-tuning. This is unfortunate also
when knowing that dimmers, ballasts and drivers behave differently as we learned on
the dimming ballast study described in chapter 2.2.
6.6 IT Department
Systems that are connected to common network require careful planning to avoid
security vulnerabilities. Physical access restriction to computers running the control
software is not adequate security solution, since the resources could be accessed
remotely. The network connections can also change over time time, possibly
compromising the security that was based on the assumptions that the system is
controlled only on a single PC.
If the system provides maintenance staff error messages as text messages, it must be
verified that the GSM modem does not open access into the network during the time it
connects to reporting or mail server.
Backups are required for a number of reasons. A system that manages thousands of
devices requires a significant effort to be programmed. When changes in programming
are made, sometimes mistakes are made and the fastest way to recover the system is
to restore the most recent backup.
6.6.3 Virus Protection
Even when control system computers are not connected to common network and the
Internet, they are still vulnerable for viruses. The USB memory sticks used when
installing upgrades may contain malware that will then infect the system. Some viruses
such as Stuxnet target specifically the automation systems, motor drives and the PLCs
that might exist in the same network with the lighting control equipment.
6.6.4 Disaster Recovery
Critical systems must have a method to restore their functionality no matter what the
problem is. When the system is running on PC, there can be hardware failures such as
damaged hard disk, issues on the operating systems or bugs in the software itself. The
software of control system must be then provided in a way that allows its re-installation
with the latest configuration and backup. This procedure must be included in the super
Since the standard PC hardware, especially the ‘Office-grade PCs’ have a limited
lifetime, it has become more common to virtualize the the PCs running automation
related processes with systems like the Vmware ESXi or Microsoft Hyper-V. The idea
is that a single physical high-end server runs the ‘servers’ as virtual machines. As
addition to the more effective use of hardware and less machines in the server room,
this approach will have other major benefits as well:
• Virtual machines are easy and fast to backup and restore as a complete system
• The virtualization platform can provide High-Availability option, which means
that for each online virtual machine, there is a synchronized copy of it in offline
mode. If the first virtual machine stops or crashes, the offline unit will
immediately go online and continue running the process. The switchover can
happen in a couple of seconds and the second hardware can be located in
another room or building. The HA –option also works as a complete backup
• Any existing PC running Windows –based control system can be virtualized.
• When doing software upgrades or major changes in programming, the operator
can take a memory snapshot of the current state of the server. If something
goes wrong, he can then jump back to the snapshot and no functionality is lost.
6.6.6 Network Access and Firewalls
It is often thought that when the system has its own switches there is no need for any
additional security. With this approach, the security of the system is easily
compromised later on when changes are made to the system and new control PCs
added. The network should be planned from the beginning in a way that changes can
be made and new units can be added anywhere in the building.
The access to the network should also be restricted internally. This can be
accomplished in networks where a firewall manages the routing of traffic instead of
core switches. With this approach the traffic between virtual networks (VLANs) can be
restricted on port basis. This is beneficial also in order to limit the problems arise when
a malfunctioning device causes a lot of traffic to the network, ultimately jamming it.
6.7.1 Facilities Management
The facility managers requirement is a reliable system that has a reasonable return on
investment, low maintenance cost and that is flexible to meet the new requirements
there might be. In commercial buildings the control system features and advanced
lighting options may increase the market value of rental spaces.
Recently, a widely discussed topic has been energy conservation and the technical
capabilities required to meet the new standards. In order to get a building permit the
energy consumption of building must be below the set levels and the use of electrical
energy is followed more closely and has lower limits than the other forms of energy.
Therefore a control system that is capable of lowering the electrical energy
consumption can become a key factor for the building project to get required approvals.
The control and automation systems have components that have a limited lifetime.
When the changing of lamps requires a significant effort, being able to schedule the
maintenance operations well in advance saves maintenance costs.
6.7.2 Electronic Building Manual
Electronic Building Manual (EBM) incorporates the health and safety file, operating and
maintenance manuals, record drawings and other related information for the
installation. All the text and drawings should be in a standard electronic format. The
manual should be easily upgraded in the future. One common function of the EBM
system is to store energy consumption data of which trends can be formed later on.
Lighting design produces a number of documents that should be part of the electronic
building manual. While it is common that the building manual only contains CAD –
drawings in their original formats, system-specific files such as DIAlux –files, the ETS5
–project file for KNX and the Digidim Toolbox –project files for DALI should be stored to
EBM with adequate version control information. The ETS5 –tool is also capable to
prepare useful reports of topology and programmed group objects that should be
included in the EBM.
Helpdesk is currently a function in electronic building manual or a completely manual
process. A building automation system could have a role in the helpdesk process in
identifying the actual device requiring attention. The helpdesk processes however are
complicated. If the maintenance is outsourced, the helpdesk is linked to ERP and CRM
–processes and it is essential that the client manager also has a view on issues and
their resolutions as well as the local maintenance person. An important function in a
helpdesk is the ability to escalate issues to a specialist that may use another system or
6.7.4 Accurate System Time
When the system has a clock switch function for timed lighting scenes, it is important to
be able to maintain time accurately. When the switch to daylight saving is due on early
Sunday mornings, this change should be done automatically. In a public space where
the building’s hours of operation should match with certain lighting scene, it is essential
that the time of the control system is no more than one second before or after the
There should be an option to use NTP as the source of time since GPS signal is not
available in electrical rooms and mounting an antenna and routing the cable from roof
to electrical room may be too much an effort.
6.8 Energy Saving Regulations
The European Union has collected requirements related to energy performance of
buildings into an overreaching standard EPBD (CEN/TC 371). The standard specifies a
general framework for the assessment of overall energy use of a building and the
calculation of energy ratings in terms of primary energy consumption.
In Europe the energy saving regulations typically treat the building as an entity and do
not set specific requirements on functions inside. The exception would be the choice of
light sources that is becoming more limited while traditional light bulbs and some
fluorescent light sources have been banned. When some light sources are not
anymore available, they need to be replaced with another types and that will require
also some adjustments in the lighting scenes and possibly also on components of the
The most widely accepted energy certification frameworks are BREEAM and LEED.
These frameworks include very few exact requirements that should be noted when
planning a lighting control systems. The certification frameworks may however require
that each occupant has its own energy metering. In a shopping mall each shop should
then have energy meters for water, electricity and heating. This is not always the case.
However, for this purpose the energy metering does not need to be as accurate as for
billing purposes. Therefore the meter can be added later on the nearest electric
In the United States, the ASHRAE 90.1 defines some specific functions that would
lower the energy consumption. As an example, it requires automatic shutdown of
building lighting at time-of-day for buildings over 465 m2. [10, 93] In some other states it
is required that the exterior lighting is automatically dimmed at least 50 % during non-
business hours. There is also a requirement that the controlled lighting shall have at
least one control step between 30-70% of full lighting power in addition to all off.
Similarly to European standards, the ASHRAE -standard also gives an exact lighting
power allowances for each type of spaces. These requirements can only be met when
the lighting system is centrally managed.
The states may have more specific regulations for electrical systems than what has
been adopted at the federal level. The State of California introduced Title 24 Building
Energy Efficiency Standards as of January 1st, 2014. The new standards will require
the majority of new commercial interior lighting systems to be dimmable by the users
and have a high degree of dimming control resolution. [3, 1]
7 Functional Requirements for Building Automation System
The functional requirements for an ideal building automation system are derived from
the user requirements defined earlier.
7.2 System Architecture
The building automation system should be flexible in what kind of subsystems it can
manage. A common requirement could be that the lighting is controlled with Dali, other
electrical systems with KNX and the HVAC with some other method. It should be
possible to later connect new subsystems.
The system should rely on Ethernet as its backbone. The central control network
should be designed as any critical industrial control network.
7.3 User Roles
The automation system should not be limited only to facility maintenance personnel.
The system should also support users with the following roles:
• Lighting designer
• Lighting operator
• Security personnel
• Front desk personnel
The system must be designed to operate 24/7 for years. The security updates or
software upgrades should not affect on the operations of the facility.
The automation system should be easy to operate byt users in different roles. The user
should not be able to access functions not required by his role. The user interfaces
should be intuitive and not require extensive training by the users.
7.6.1 Physical Security
Physical security describes security measures that are designed to deny unauthorized
access to facilities, equipment and resources. It involves the use of multiple layers of
interdependent systems which include CCTV surveillance, security guards, protective
barriers, locks, access control protocols and other techniques.
Building automation and lighting control systems are often installed in places that don’t
meet the criteria to provide a reasonable level of physical security. There are very few
standards that would help to define the requirements for security measures. A
recommendation would be to follow the best practises defined for telecommunications
and ICT server rooms. In Finland, the Finnish Communications Regulatory Authority
FICORA introduced in 2006 a regulation on locking of properties telecommunications
rooms and later in 2012 a regulation for facilities that provide critical ICT services.
The key requirements that should be adopted on building automation rooms are:
• all doors leading to the room have are monitored by an access control system
that can provide required level of access for each operator and logs the entries
into the room
• the room is monitored by a security alarm system
• the entry door to the room is monitored by a CCTV camera
• all construction materials are fire-proof
• the doors are made of material that is reinforced
• if the room has windows, they must be covered to prevent viewing in from
outside the building
• the room must be monitored with a smoke or heat detector
• the room temperature must be monitored and an automatic alarm must be sent
to maintenance personnel when set level is reached
7.6.2 Information Security
The control system must have a personal account for each operator with passwords
they only know themselves. The user profiles shall be planned so that the operators
can only access the functions they have been trained for.
System malfunctions are monitored using a network management system. It will raise
an alarm when a connected device does not anymore respond. The monitoring function
should be separated from the built-in functions the control system software might have
since the control server is also a monitored object.
The control systems rely on backbone network that is TCP/IP. The security of the
connections need to be maintained with firewalls and network access restriction, e.g.
by limiting access to specified switch ports only.
The system should be available as a smaller scale ‘demo’ installation for proof-of-
concept requirements. The system should be capable of utilizing existing technical
documents such as the CAD –drawings and ETS or Digidim Toolbox project files.
The system should require as little maintenance as possible. It’s functionality and
security should however be maintained at a safe level.
When a central network management system is available, the following situations
should be added to the monitoring [11, 213]:
• Degraded bandwidth
• Unknown personnel access
• Unknown hosts connected to network
• Missing HMI stations
• Full network emergency: go-safe-mode
When selecting components for the automation system, the component can be
centrally managed if it supports the SNMP protocol and the vendor can provide a MIB –
file that descripes its control properties.
The interviews conducted for this thesis work has given the impression that the users
with various roles are unhappy with the options available at current lighting control
systems when the controls have been based on building automation systems. It also
seems that the lighting setups are not very advanced. In Finland, it is not at all common
that even major construction projects would have a lighting designer involved in early
stages of planning. In many cases, the pre-set scenes of lighting control system are
simply defined as “100% on, 50% on and all off” for the whole space. While it is known
that dimming the lights could potentially save energy, architectural lighting design made
in a professional way could have a positive return on investment when the luminance
levels are considered carefully.
The systems based on KNX, DALI and other network protocols are advanced and their
capabilities are not fully utilized. The skill levels of both the contractors and designers
vary and the technology selections are made based on limited information. The design
teams also would benefit from having engineers with wider background: an electrical
engineer is seldom an ICT specialist and a lighting designer may not be aware of all
the possibilities or limitations of the chosen technology.
It also seems that there is no such BMS -product in the market that would provide a
reasonable level of features for all the aspects of lighting control. Because of this, the
facilities have several overlapping control systems and that is not the ideal approach.
While a number of new vendors have entered the market with products for homes and
small offices, the larger projects would still rely on industrial HMIs that don’t provide the
The level of complexity of architectural lighting controls is not going to be easier in new
projects. A construction project should not be an IT software project. The components
of electrical automation systems are mature enough and well documented. It is not
easy to come up with a design plan that would be impossible to accomplish at the
technical level. Making the system easy to operate is an another story.
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