1. No flexibility
   When there is the need to make an immediate change for a special event or a holiday, sometimes there is barely enough time to run all over to make the adjustments to meet the event.
2. Outdoor or daylit area lighting
   When the natural lighting times change with the seasons, the timer would also need to be adjusted to match which is also troublesome.
3. One timer, one panel
   Even though there would only be one setting for the timer for any given month or season, any single timer can only be used in any single panel. In a large building, it is certain that there would be multiple panels to cover different sections of any area or floor. To match the natural lighting, the timer needs to be adjusted accordingly with the month or the season, but with so many panels, this would become too cumbersome as the building manager would have to run all over to make the adjustments.
4. Incorrect or inaccurate time
   It is recommended that a lighting control system be installed and each section would have the lights controlled by the LT3100, LT3704 or some other controller modules, the control for these modules would then be centralized on an ACS touch panel. The ACS panel would be set with the desired time schedule, the ACS would be connected to the host PC, the PC would then be able to propagate its clock time to all ACS that is connected to it.

The Role and Value of Digital Switches in the Lighting Control System of a Public Building

A digital switch is not simply a new type of high end switch, but is entirely different from a classic switch. A digital switch is able to achieve that which not possible with a classic switch.

What is a Lighting Control System?

A lighting control system is a way of optimizing the wiring for the lighting as applied to a public or commercial buildings. Digital switches connect to the lighting control panel through the digital trunk line constitute an entirely different method of wiring setup as compared with the traditional form of wiring made up of classic switches through electrical power circuits.

The Role of the Switch

No matter what type of switch, its one indispensable function is the convenience of operation that it should provide to the user.

When this switch is operated, it should tell the lights to turn on or off, thus a wall switch is made for the convenience of the user.

Evaluating a Good Switch from a Bad One

1. The closer the switch is to where the user needs it, the better the switch is at serving its purpose. The faster its feedback and the more lights that it can control, then the more convenient it is. The opposite is when the user needs to travel far then the poorer the switch is at doing its function.
2. The more straightforward  and intuitive the switch is to use, the better the switch is. On the other hand, when the user is faced with a wall of switches, then it is not obvious which switch controls which light. Especially cumbersome if several group of switches needs to be operated just to find the right one.
3. The easier it is to configure or adjust the switch to meet the partitioning of the space, the better the switch.
   In order to meet the needs of any given public or commercial space, the space often needs to be partitioned in a manner appropriate for its intended use. In the traditional method, since the lights and switch are in a one to one absolute correspondence, there is absolutely no flexibility, in order to change the layout, the wiring needs to be renovated physically, which is laborious, expensive, time consuming and disruptive to the business.

A lighting control system is used mostly for the control of the lights in public facilities, and they can either become a standalone system or a subsystem of the building automation system. In which case, why not just just the DDC for controlling the lights as well. 

The focal point of a building automation system is the control center. But in a lighting control system there can be both a centralized control and local control, in some cases, local control can even have multiple access points and even scene recall capability.

To further elaborate:

1. Local digital switches have status feedback
   This is one of the more prominent features of the local switches of a lighting control system. Having local control and scene recall is a very basic requirement of a lighting control system, this is demonstrably a feature that cannot be performed by the administrator at the control center. Lighting control is a control system that requires both local and central dual control.
2. For small scale applications, simply use digital switches
   Such applications often does not require the involvement of a computer based central control system, where one can simply use either the multiple digital switches or a touch panel as the user interface for centralizing control of all the lights. Such a setup is inexpensive, easy to implement, simple and convenient to operate.
3. For medium scale applications, one can implement a standalone central control system, and also integrate it into the BAS.
   The D-Bus lighting control system has an open Modbus protocol that can be used by the graphical control software on a host computer to interface with; of course, the BAS software can use this to interface with the D-Bus lighting control system as well.
4. For large scale applications, it is strongly recommended that one have a single centralized point of control. Otherwise, there would be far too many touch panels distributed all over to control the lights in various areas. It is further recommended that there should be a second duplicated central control in case the first one fails.
5. Cost and backup considerations
   Even if only the central control is implemented without any local controls, the cost is still much lower than that of a BAS. One should also consider that when the central control host fails, then there must be some form of backup control, on this point, it is also easier to implement this in a lighting control system and the cost is also much lower.
6. Lighting is a high voltage system
   (hardware wise it is inadequate, because of small relays, colossal engineering cost, multiple wires)
   A BAS specializes in central HVAC control and the safety system, while a lighting control system specializes in lighting control. Even though a BAS can be used for lighting control, doing so is clumsy and expensive, since each control point needs to have its own contactor and wiring, all the wiring combined will result in a mass of wires snaking from panel to panel.
   Contrast this approach with a dedicated lighting control system wherein the hardware components are designed specifically for lighting. Which results in simplified engineering work and greatly reduced costs.
   If the building does not have central HVAC, but instead uses local air conditioners such as box types or split type air conditioners, or  if they don’t have any air conditioners at all, then the BAS would be used exclusively on lighting and its strong suite would be completely wasted. In which case why not simply use a dedicated lighting control system in the first place.
7. Combining monitoring with control makes things more direct and reliable.
   The most expensive hardware portion of a BAS is the DDC, and since it is a low voltage system; every lighting load that it needs to control would be through its DO ports controlling the intermediate magnetic contactors. While the status feedback would return to the DDC through its DI ports.
   In contrast, in a dedicated lighting control system, the controller and the relay is combined together and there is no need for an external magnetic contactor,
   In a lighting control system, the load control and feedback are combined into the same unit. The wiring is more straightforward and there is no need for any separate DI ports for the feedback signal. There is also no need to perform any sort of special programming as all the logic is already built into the unit.
   In a BAS, all of these are considered as separate and extra material, panel wiring and programming costs. Of course, all of these costs is greatly reduced or obviated in a lighting control system, with the additional benefit of less space occupied.

How can one control the lighting for places such as a shopping mall or a factory floor so that they can all be turned on or off at the same time?

One should make use of magnetic contactors for their large current capacity in conjunction the LT3100. A single LT3100 has 4 channels for controlling up to 4 magnetic contactors. An ACS40 touch panel as the user control interface with its automatic scheduled control is ideal for use to turn the lights on and off from a preset schedule.

An item worth mentioning is that even though it is lighting for large areas, one should still consider having two periods of control, one should be for all the lights to remain on during business hours. While the other is for after business hours, in which only the important lights should remain on, while the rest are turned off in order to save on energy.

What types of control interface are suited for a building with many different areas, but all of which are centrally controlled?

Choice can be made based on the number of circuits for each area as follows:

1. 24 circuits or less: It is recommended that the IS45 digital switch be used; each button can be labeled and reflect the status of the lights in the each area.
2. 24 to 60 circuits: It is recommended that the ACS40 user control interface touch panel be used.
3. 60 to 120 circuits: It is recommended that the ACS50 user control interface touch panel be used.
4. More than 120 circuits: A PC with a suitable graphical software together with a user control interface touch panel. A user control interface touch panel by itself is also suitable.
5. Dedicated Control Panel: As a hotel guest room headboard control panel, or for the sales counter in commercial lighting setting.

1. The one-to-one relationship between the wall switch and the lighting circuit is completely decoupled.
   There really is no need to limit the wiring so that one switch controls only one lighting. By decoupling the switch from the lighting, the lighting can be controlled from any switch and any switch can control any lighting. The relationship between any switch or lighting is defined digitally and can be reprogrammed without physically rewiring the lighting circuits.
2. Digital switches can occupy less wall space.
   A classic wall switch has at most 3 gangs, but digital switches can have as many as 8 gangs (In the US, the situation is much worse as each switch can have only one button). Thus, more can occupy the same amount of wall space.
3. Each button can be independently assigned.
   There are multiple buttons on each digital switch and each one can be assigned to a different function independently of the others. Not only can each button be assigned to control separate circuits, they can also be assigned to control groups or patterns.
4. Greatly reduces the wiring work.
   Digital switches are wired based on a digital signal bus, even if there are lots of digital switches, the wiring is still very simple. In addition, expanding the number of switches in the future is very simply, as one only needs to extend the bus.
5. The more lighting circuits there are, the greater the amount of simplification (with scene switches).
   When a room seeks to be both stylish and energy saving, the circuit wiring becomes more elaborate, but the beneficial effect becomes even more pronounced. So even though there are more circuits, the number of digital switches can be lessened by making use of patterns; and in addition, the less complicated it becomes to operate.
   The more elegant the atmosphere for the room, the more lighting circuits there will be. In the traditional approach, not only are there more circuits and the wiring becomes quite complicated, the operator will thus be faced with a wall of switches and will have great difficulty in determining how to switch the right ones to obtain the desired scene. But if digital switches are used, a single switch can be assigned to several circuits, which greatly reduces the number of switches, and simplifies the work of the operator.
6. Reconfigurable lighting layout.
   In a commercial or public setting, being able to reconfigure the lighting layout is highly desirable when the space needs to be repartitioned for different purposes. With traditional lighting, this can only be done by physically rewiring the circuits and adding new switches is a laborious, expensive and time consuming process, not to mention the disruption it brings to the usage of the space.
   On the other hand, with digital switches, the new layout can be reprogrammed digitally, and new switches can be added anywhere near the digital bus with just a few wires.
7. For large areas, one can install multiple switches in various locations for convenience in operation.
   When the space occupied by a room is vast and there is only a single centralized control interface, the user would need to traverse long distances to control the lights. But if there are multiple digital switches spread out over several locations, then lights could be multiply accessed and the user can operate the switches nearest their work location.
8. Remote monitoring and control.
   The main benefit of centralizing control is the ability to remotely view and control the lights for the entire building. In addition, one can also add the capability for scheduled control to further improve the benefits from having a lighting control system.

Scene Lighting Control For Meeting Rooms

Each company office needs to have a meeting room, and some have showrooms as well. A meeting room serves not just as a place to exchange ideas, it is also a place to receive customers, to conduct business, make presentations and most often has the greatest impression as it is what most people outside the company will ever see. As such, the meeting room is often the most lavishly furnished and decorated room. The larger the company, the larger the meeting room. A meeting room have all sorts of needs, both big and small; and requires that the space is flexible enough to serve as a venue for all sorts of events.

Imbue With Technology

In a meeting room environment, other than the furnishing and interior decoration, the most important aspect is the different types of scene lighting needed to set the proper mood for each event. Such as a meeting, conference, presentation, negotiations and so on.

Different activities would require different combinations of lighting and usage of the projector screen. With just a small investment, the meeting room can be imbued with the sophistication of technology.

Just One Touch

One can make use of the touch panel, touch switch, mobile phone, tablets, or a combination thereof; regardless of the interface device chosen, one can recall a preset scene with the touch of a button. The scene can be any combination of lights being on or off, curtains being opened or closed, or projection screen being raised or lowered. Contrast this approach with the traditional approach of chaotically mucking around with multiple remote controls to set each and every one of the lighting and equipment individually. One touch, no fuss.

Classy But Not Expensive

Such a system is both sophisticated and classy, but it doesn’t need to be prohibitively expensive and can actually be quite affordable even for companies with a modest budget. Truly a great deal and well worth its value.

The third generation of the D-Bus lighting control system is optimized for smart energy saving control; with convenience, speed and energy saving as its core tenet have the following 8 unique features.

1. No CPU. This system is not dependent on having a central computer nor does it need a customized central processing unit; thus there is no single point of failure that can bring down the entire system.
2. Digital switches do not have an address and thus do not take away from the address pool. They are easy to configure and each of their buttons can have user provided labels.
3. It can include sensors and classic switches for use as local control.
4. This system can also control curtains, air conditioners and magnetic contactors.
5. Specialized modules. One module has failsafe switch ports and another has relay outputs specifically designed for the high inrush currents of LED lighting.
6. A mobile device or a PC can be used as the control interface when it interfaces to the system through the Internet. There is little latency for the response is fast for both the command and feedback from the system.
7. Some controllers have special energy saving logic built in and thus do not need to have custom programming, the unit needs only to be configured simply using a mobile phone or tablet.
8. Backup control for verifying the installation ,diagnosing the system during repair or maintenance.

The basic purpose of having a lighting control system for public or commercial buildings, under the premise of reducing staff manpower and simplifying user operation; one strives to achieve the dual benefits of energy savings and increasing the classiness of the lighted space.

Digital lighting controls have evolved over 20 years and can be divided into 3 generations:

1. First Generation – N+1 Lighting Control System
   1. Eliminate the one-to-one correspondence between the lighting and switch in the traditional approach to electrical wiring; and replace the electrical power wires with signal wires. Which is where the N+1 designation originated from.
   2. The relay can then be controlled from either the local switch or remotely from the centralized control.
2. Second Generation – Two Wire Bus Lighting Control System
   1. Replace the traditional switch with digital switch for both local and centralized control (the N+1 number of wires needed is now reduced to 2 wires). The lighting can be controlled from either the local switch or remotely from the centralized control. Thus, the distance can be greatly extended, and the number of circuits is also greatly expanded. The electrical circuits can be laid out more flexibly.
   2. It is possible to implement groups, patterns and scheduled forms of intelligent control.
3. Third Generation – Energy Saving Lighting Control System
   1. Incorporate energy saving sensor switches into the system. Combining centralized control, local control and movement sensors into a energy saving lighting control system.
   2. Incorporating mobile tablets and phones through the ubiquitous Internet into the lighting control system which smashes the geographical limitation of having a fixed centralized control, giving the system administrator a new level of convenience and mobility.
   3. A higher level of dimming control, not only for the purpose of saving energy but also improves the atmosphere of the space and increases the elegance and quality of the space.

DAE’s Lighting Control System

1. DAE’s lighting control system is third generation; in addition, it goes one step further and incorporates safety alarm sensors into the system; resulting in a unified lighting control system with energy saving and safety.
2. Applications for our lighting control system is divided into 4 main categories; public buildings, scene lighting for commercial spaces, smart homes and hotel guest rooms.