When I was in about tenth grade, I lit my first rock show. It was in my high school foyer during the homecoming dance. We didn’t have any kind of portable lighting control in my school. I ended up taking down four Fresnels in the theatre and hanging them on the volley ball net stands that I “borrowed” from the gym. For control, I went to the hardware store and purchased four household rheostat dimmers and made my own 4 channel lighting control board. It was clunky, but it worked, and my first rock show was (in my mind) a smashing success. Not bad for a 15 year old kid in 1989. Oh, how far we have come since then.
The Beginning
Concert and event production has a lot to do with how technology has evolved in lighting control — much more than the theatrical world that it was born from has. If you look back to the shows of the 1970s they were lit with PAR cans, beam projectors and lots of ACLs. If you wanted moving lights, you hired in followspots and followspot operators. Control was likely coming from one of two sources. Whether it be one of the giant rheostat dimmer systems that looked like they belonged in a Frankenstein movie or a more conventional two-scene preset board, this is what was out there. Going forward, a company called Fantasee Lighting out of Detroit came up with the Cyklops in the late 1970s. This was the first automated light to be used in concert lighting, and luckily for all of us, it was far from the last. On a sales trip to Fantasee a few years ago, I got to see one of these guys. I felt like an astronomer getting to see the big bang happen. It was very cool to see how the developers of the Cyklops identified the problem of needing a cooler effect and then executing an idea. Like most early automated lights, each Cyklops had to be individually controlled. Because of the evolving complexity of shows, the single light, single controller thing had to change.
“Moving” Along
Once the lighting manufacturers figured out that they needed to be able to control more than one light at a time, each one came up with a protocol for controlling their lights. This is fine if you only want to use one manufacturer in your rig, but mixing manufacturers could prove to be problematic. Even then, you would have had one controller for your static lights and one controller for your automated lights, and those two controllers were not talking to each other. In my opinion, the people running the shows during the earlier days of automated lighting were the real deal. I tip my hat to them.
The first attempt at a unified lighting control protocol was AMX (Analog MutipleXing). AMX could control up to 192 individual control channels over one cable. This was a huge step forward, because now a lot more lights could easily be controlled from one desk. However, AMX was primarily used for dimming control, and not for controlling automated lights. Those more complex fixtures were still being controlled by proprietary controllers, like the Artisan Consoles that ran Vari*Lite fixtures, or the Compulite console that was running Telescans beginning in 1984.
Finally, in 1988, DMX (Digital MutlipleX) was standardized by USITT. This made it so that everyone was supposed to adhere to one standard of communication for entertainment lighting control. This also made it so that no matter what lighting controller you wanted to use, as long as it was outputting DMX, it could control any fixture that would take DMX input. So now we could control up to 512 channels (one universe) with one cable going from the desk to the dimmer racks or automated lights, as the case may be. When DMX first really hit the scene, very few people could imagine using all 512 channels on one stage. In fact, some manufacturers of controllers did not even offer a full universe of DMX as a standard. If you wanted more than 300 channels, it was an up charge. As time went on, controller manufacturers added additional universes of DMX to their consoles. This made it much easier to control larger lighting rigs with one controller. Each universe of DMX has its own cable running from the controller to its group of fixtures. At the same time that the controllers were able to process multiple universes of DMX, RDM (Remote Device Management) was also being developed. RDM, when fully implemented gives us the ability to not only send data to the fixtures, it gives the fixtures the ability to send information back to the controller. This way, a user could better monitor the fixtures in the rig to make sure that they were working properly, and if there was a problem, they could see it from the desk and have a better idea of how to handle it. The programmer could also change a DMX address from the controller as well. While this is pretty cool, RDM has still yet to be fully embraced by either the controller or the fixture manufacturers.
And Here We Are
While the vast majority of lighting gear still relies on DMX for getting information, DMX cabling is not always how it gets from the controller to the fixture. Ethernet communication has made sending multiple universes of DMX over one cable possible. In fact, with Art-Net III, it is possible to transmit up to 32,768 universes of DMX over one cable. That is a total of 16,777,316 channels of DMX that can be controlled by one console. At this point, the only limitation to that level of control is the processing power of the controller and available band width. Because Art-Net is a TCP/IP (Transmission Control Protocol/Internet Protocol) based control protocol, it can be run using standard Ethernet cable over fairly long distances. The basic idea is that you can run one control cable from the console all the way to your backstage area (I still recommend running a spare) to a variety of different Art-Net to DMX nodes that can translate your Art-Net signal back into DMX512A protocol that can drive any of today’s lighting instruments. However, because lighting fixture designers are getting much smarter about utilizing Art-Net more effectively, they are designing fixtures to be Art-Net native. For example, there may be an RJ45 plug sitting right next to the 5-pin DMX port allowing Art-Net to be inputted directly into the fixture. This makes operating fixtures that have a ton of DMX channels to be much more effectively utilized. A limitation that has always existed with TCP/IP protocols is that it can’t be daisy chained like standard DMX. However, if the fixture design team has taken the next step and installed an Ethernet switch into the fixture, then Art-Net daisy-chaining is possible. The Chauvet NEXUS and EPIX 2.0 products are examples of fixtures that have Ethernet switches installed and allow for Art-Net daisy chaining. Because of the extremely high amount of DMX channels that can be run over Art-Net, large-scale pixel-mapping projects are much easier to accomplish. Although controllers like the grandMA2, Avolites Titan and Sapphire series, Hog 4, and Martin Maxis having amazing pixel-mapping capabilities, using standard DMX to operate them becomes quite limiting because of cabling. As stated above, in standard DMX operation, one cable = one universe (512 channels). This means that I can only run 170 RGB pixels per universe. If they happen to be 16 bit, then that number drops to 85. So lets say that I am using a controller that has the ability to operate eight universes of DMX. I can run a total of 1,360 pixels in RGB mode. As a point of reference, a single EPIX Bar 2.0 uses a total of 480 channels in Art-Net mode. This is just 32 channels shy of a single universe of DMX. I could only run eight bars with 256 channels to spare on an eight-universe console that not too long ago would have been able to run a full-scale rock tour. Is it just me, or did the universes just get a lot smaller? On top of all of this capability, Art-Net enabled fixtures also have the inherent ability to send information back to the controller. The user can also (depending on the fixture) have the ability to log directly into the light using a built-in web server to do onboard diagnostics, color calibration, thermal monitoring and any other function that you could do at the display, and much more effectively than with RDM.
Art-Net is not the only TPC/IP based control protocol that is out there. MA-Net from MA Lighting, ETCNet from Electronic Theatre Controls (ETC), ShowNet from Strand and Kling-Net from ArKaos are a few examples of proprietary control systems that utilize TCP/IP architecture. Each one of these protocols have the ability to transmit large amounts of information over one cable. It is clear that the future is going to be controlled over an Ethernet cable.
Michael Graham is the product development manager for Chauvet Professional. He also has a background that includes design and installation of lighting systems for both entertainment and architectural lighting.
