Try to imagine what it would be like attending a concert, a live theater performance or a dance club without a coordinated light show. How would that impact the experience? With the phenomenal effects that can be achieved thanks to advancements in lighting over the past decade, it would not be nearly the same.
Ethernet is expanding as a means to communicate control signals that vary the intensity, color, timing and position of elements in theater and stage lighting systems.
Years ago, most lighting systems communicated using proprietary serial protocols. This made interoperability between different manufacturers’ equipment problematic or impossible. To remedy this situation, the lighting industry got together and agreed that one common standard digital protocol must be created.
Before we discuss the ways that Ethernet can support theater and stage lighting, let’s first take a look at applicable standards.
DMX512 is a standard for digital communication networks commonly used to control stage lighting and effects; it was originally intended as a standardized method for controlling light dimmers. Developed by the United States Institute for Theatre Technology (USITT) Engineering Commission, the DMX512 standard (for “digital multiplex with 512 pieces of information”) was created in 1986, with subsequent revisions in 1990 leading to USITT DMX512/1990.
In 1998, the Entertainment Services and Technology Association (ESTA) began a revision process to develop DMX512 as an ANSI standard. The resulting revised standard, known officially as “Entertainment Technology – USITT DMX512-A – Asynchronous Serial Digital Data Transmission Standard for Controlling Lighting Equipment and Accessories,” was approved by the American National Standards Institute (ANSI) in November 2004. It was revised again in 2008, and is the current standard known today as “E1.11 – 2008, USITT DMX512-A” (or just “DMX512-A”).
In January 2011, ESTA merged with the Professional Lighting and Sound Association (PLASA), a similar organization in the UK. The new organization, operating as PLASA, maintains all ESTA standards.
1. The Need for Higher Bandwidth
The DMX standard protocols have been a vast improvement. The lighting industry now has a tool to create coordinated effects with equipment available from a vast number of manufacturers. Advances in LED and laser systems have added even more ways for designers and technicians to be creative. A problem arose, though; the limit of 512 pieces of information sent serially using the serial DMX protocol to the now vast number of devices in an installation was insufficient.
2. Why Not Internet Protocol (IP)?
The increasing challenge of transporting large amounts of time-sensitive information has been faced by the IT industry, so why not apply that knowledge to stage lighting? The technicians in the theater and stage lighting industry realized that, with an Ethernet network – using Internet Protocol or IP connections to DMX gateways – a high-bandwidth, low-latency network could be established to support expanding requirements for complex, multifaceted theater and stage lighting shows.
Of course, to implement a structured cabling system to support this application, the recommendations in the ANSI/TIA-568 and ANSI/TIA-569 series of telecommunications standards related to 100 Ohm balanced twisted pair and optical fiber cabling would apply.
Because an Ethernet/IP network is scalable, it can be used at many different types of venues, from the largest sports stadium or performance stage on Broadway (with thousands of connected devices) to a small community theater or community college that may have just a few components to control.
Moreover, the standard means of using IP addressing and simple star topology to set up the network means that there are plenty of technical resources available. Building systems are also using IP-controlled lighting systems for exterior accent lighting. This allows the building owner to have special-effects programs for holidays and celebrations.
Same, But Different
By no means do I claim to be an expert on theater or stage lighting, but I have designed quite a few structured cabling systems for Ethernet/IP networks. Based upon my knowledge, here are a few of the differences that could impact a design specifically for theater or stage lighting:
- Cables must all be black and may require shielding
- Tactical cable may be required
- Four-pair Power over Ethernet (PoE) must be considered
- Category 6A is recommended for all new installations
- EtherCON ruggedized, lockable RJ45 connectors could be required
- OpticalCON ruggedized, lockable fiber connectors could be required
- Redundancy, including cabling and power supplies
There are industry-specific protocols used in theater and stage lighting systems that need to be taken into consideration when selecting the layer 2/3 network switches. The following are some of the most commonly seen protocols that may have to be handled by the layer 2/3 switch:
- Allen & Heath ACE™
- Audinate Dante™
- MA Lighting MANet 1&2
- QSC™ Q-LAN
- Roland® REAC
Additionally, check that the layer 2/3 switch you plan to use is ready for future audio-video bridging (AVB) upgrades.
Belden has a complete portfolio of DMX cabling for the connection from the IP to DMX gateway to lighting components. One example is the popular 9841 24 AWG cable, which is available in CM, LSZH and plenum versions. Please see our lighting cable catalog for more information.
Alfred Greiner's career has focused on the physical and network layer design and engineering requirements to support Information and Communications Technology (ICT) infrastructure which conform to North American and/or International standards. Other areas of interest are North American and International standards for electrical distribution systems for ICT, along with advancing his understanding of effective methods to regulate the environment for ICT equipment in server rooms and data centers, all with a focus on sustainability and energy efficiency. His 25 years of experience includes design/engineering of structured cabling and project management for large-scale new and renovation building projects for enterprise, government, universities and health care institutions. Many of these projects include a supporting data center space or cloud connectivity. This involved collaborating with clients, architects, engineers and IT staff as part of an architectural design team utilizing AIA, CSI, RIBA and LEED processes to design and document a comprehensive IEEE, EIA/TIA or ISO standards-based structured cabling system to support converged information technology systems and distributed wireless systems.