Since the revolutionary idea of Edison's – turn a switch on wall and the lights will come on, things have progressed. There is a lot more we can do with lights nowadays than just switch them on and off.Edison had to put up these signs saying there was a key by the wall because people were generally used to lighting luminaires with a match. Given what lighting can do these days, 100 years on, a simple switch is getting a little bit insufficient. It is time, again, to introduce a new way of controlling the light.
The fact is that now, with the right lighting tools, you are no longer limited to illuminating effects. You can actually think about how a space looks and what you do to it. So often light can define space, spatial boundaries, the periphery of our vision.
With light being such a fluid medium not only can we actually alter the shape of that boundary, the spatial envelope, but we can change it at will. No longer is it necessary to install another luminaire, or take down old ones as requirements change, with fore planning everything is possible.
In reality this is using layers of light – you can have countless layers. You might have a general layer using all the lighting to give an ambient effect... then there might be a second layer which is lighting the architectural elements, and a third layer using colour, but it's exactly what we do in architecture – we create layers.
To change between the layers we need some hardware – some kind of control panel. In the past we have ended up with a very large switch cabinet. In theatrical events there are big boxes, dimmer racks, switch gear and wires everywhere.
So where should we be going with this? Everything else in life now is networked, we talk about computer networks, the tills in the supermarket are networked, everything runs on Ethernet, LAN, wire-less LAN, Wi-Fi... abbreviations and acronyms everywhere.
What if we could just put a network together where everything belonging to a luminaire is housed inside it, everything needed to operate it; changing colours; dimming - whatever it does. Then we could just send it a signal and give it an instruction.
So that's our vision - integrated luminaires, all the hardware is built into it. Added to that it should have some ability to communicate so that we can send messages to it. We can ask questions - What can it do? What colour is it set to? Is everything working OK?
Finally we want to be able to identify the luminaires. If we are talking to devices on the network, we want to know exactly which one we're talking to.
The system we use is called DALI. This is an open standard, it's not connected to any one manufacturer. Any manufacturer can decide if they want to create a luminaire compatible with DALI and follow the rules for voltage levels, controls, and signalling. Anyone can create, even in your own home, a DALI compatible product.
The huge advantage is it strips away the industry politics over protocols, etc. Another is that you can use an ERCO luminaire in someone else's DALI control system, or use somebody else's lumi-naire in our DALI control system.
The whole concept of a controls protocol is one that is often thought of as difficult. In addition to DALI, there is also DMX that is used in theatre lighting and lots of other controls protocols. However, they all share certain parameters
There are three elements common to all controls systems or a control network. First of all a network line (the transmission cable and voltages for your instructions), then the protocol (we need a language to communicate in) and finally each element needs an identity - a name.
This particular electrical standard just uses two wires. The bus wire is simply linked to all components in the system from one to the next in an electrical 'daisy chain'. They then use the DALI lan-guage to transmit any instructions to and fro.
As the luminaires get connected, the Light Server can find out what is going on.
Installation is significantly easier than conventional 'analogue' sys-tems. Once the electrician has hung all the luminaires in the ceil-ing and connected power, all will come on. If the DALI network line has been connected too (usually in the same cable) then the Light-Server will quickly and automatically interrogate the whole network – each luminaire individually - to discover what luminaires are connected, how many and what each can do.
Electrical contractors being what they are, tend to do everything as quickly as they can and get the invoice in. But we need to know if what they have done actually works, so we use a very simple commissioning tool. This will test whether the system is correctly installed, is working and even if the correct colour lamps are installed! Then the electrical contractor can leave the site.
The development of DALI track accessories has also enabled the well-established and reliable ERCO track to be used for the operation of DALI-compatible spotlights via the Light System DALI. The track itself is unchanged – we just make different electrical con-nections.
Once installed, the ERCO Light System DALI is controlled by the Light Server, which can handle up to 64 addressable DALI devices, but by networking to other Light Servers of the same type, the sys-tem can be expanded to virtually any size. The Light Server stores system and scene data and provides the control functions.
In the ERCO Light System DALI all the ERCO luminaires are factory coded and have their own identity. We call them Light Clients. When a PC is connected with the Light Studio software, all the Clients can be identified on screen by name, image or technical specification.
Ideally, in our world, the programming of the lighting would be done by the architect or lighting designer. You do the programming and only give the user the option which of your programmed scenes they pick from a little white plate that sits on the wall - something quite familiar. What neither the architect nor the client sees is the essential brains behind it all. You do all your programming on the laptop, put all the information down into the brain (the Light Server) and you walk away. You're left with just a push-button scene selection. The day-to-day operation is by a wall-mounted control panel - ERCO Light Changer - or any other commercially available push buttons.
The Light Studio is a piece of programming software for actually creating light scenes using real language. Rather than bits and bytes and numbers and machine-code commands. Here is something that is going to do what we said at the beginning, give the control back to the designer. Now we can start lighting scenes in a more finely tuned way.
You can create scenes, you can create zones, change them for different times of the day, of the week, of the year, special events like the world cup, whatever you choose. The scenographic tools open new possibilities and new ways to think of lighting. Perhaps the greatest departure from the accepted norm - lighting scenes no longer need to be static...
Article by Tad Trylski
