Last month, I talked a bit about the recently approved ACN (Architecture for Control Networks) standard. Now that you know a little more about the reasons for the new standard and some of the underlying concepts, I’m going to talk about a couple of specific pieces to the puzzle that will benefit systems large and small.
Science Insusceptible
One of the most important things to understand about ACN is that the architecture relies on existing network technologies. Put simply, ACN will allow you to control compatible devices over a computer network. Because of this, you’ll be able to customize your control networks to be as simple (or as complex) as necessary. By making use of inexpensive Ethernet cable and switches, you’ll be able to build a control network suitable for a high school theatre or an arena-bound rock show.
While some of the devices in the network will still have the XLR-style DMX512 connectors that you’re used to seeing, other devices will have 8P8C (Cat5 or Cat6) connectors on-board. In fact, some major manufacturers are already shipping products that support the approved standard. Because of the wide availability of computer networking components, signal distribution for your lighting systems will become easier to expand. Modern facilities with large amounts of built-in network patch points will allow you to get the signal easily from one area of a facility to another with minimal difficulty.
Logic So Inflexible
With the rise of media servers, huge arrays of LEDs and whatever new technology tomorrow might bring, ACN has been purposefully de-veloped to assume nothing about the control needs of the future. While this may make it sound a bit too abstract, consider that media servers and LED products are quickly filling up our output capabilities. With only about a half-dozen of the most expensive consoles on the market able to offer up more than four universes of DMX512, more and more users are seeing the limits of today’s consoles.
Hopefully, this will become a thing of the past, as more and more consoles arrive without physical DMX512 connectors on the back. DMX512 output nodes and network patch points will be added as necessary to connect the control equipment with light fixtures, media serv-ers and whatever else we can come up with. Unlike today’s protocols, it will be much easier to add on to ACN in the future.
Because of the way the standard was written, additional feature sets and protocols can be added on like Lego bricks. In fact, standards al-ready are being drafted to add new functionality to ACN. BSR E1.31 and BSR E1.33 are both DMX512-over-ACN new standards under de-velopment.
Casually Connectable
Although ACN is expected to become the standard for theatrical control in the future, there will remain a need for a simple and robust communications protocol like DMX512. Because of this, one of the first updates to ACN is being called DMX-over-ACN or Streaming ACN. Officially referred to as “BSR E1.31, lightweight streaming protocol for transport of DMX512 using ACN,” the aim of the protocol is to pro-vide a simple standard for carrying DMX512 over a network connection while maintaining full compatibility with the ACN standard.
This type of technology currently exists, and companies like Artistic Licence, Pathway, ETC and Strand offer similar products that fulfill the need for transporting DMX512 over a network. While there likely will be subtle differences between the new standard and these existing platforms, the most important reason for the new DMX-over-ACN standard is its interoperability within the ACN standard.
Alongside DMX-over-ACN will come an update to the existing RDM standard. These extensions to the DMX-over-ACN protocol will al-low for the use of the existing RDM feature set (ANSI E1.20) in a network and is “intended to be suitable for implementation in hardware with very limited resources, which is expected to be used in simpler entertainment lighting control systems.”
Yet Nothing Invincible
The key to all of this is, of course, adoption of the standard by the industry. The development of these standards is handled by the Control Protocols Working Group at ESTA, few of whom are ever thanked for their hard work — work that benefits everyone in our industry.
Along with ensuring the robust and enduring nature of these protocols, the group also works hard to make sure that the technologies are easy to adopt and have benefits for all users. While every one of these standards and protocols is discussed, debated and presented for public review, the ultimate test is adoption by the industry.
As a closing thought, the word “synchronicity” can be defined as the experience of two or more events which occur in a meaningful manner, but which are causally inexplicable to the person or persons experiencing them. As I go about my day-to-day job of shining lights at people, I am constantly thankful for the synchronicity that occurs around me. It’s, in part, because of the industry’s use of standards like these that I can do this.
For more information on the new standards discussed in this article, visit the ESTA Web site at http://www.esta.org/.
Phil Gilbert is a freelance lighting designer and programmer. You can contact (or correct) him at pgilbert@ plsn.com.
