Understanding DMX - Seasonal Entertainment

Understanding DMX
It really is that simple!
A simple, easy to use guide for understanding and using DMX
Updated 2/29/12
Introduction
The world of DMX tends to be a scary one for a lot of people. There are a lot of rumors out there
making people stay away from adding exciting DMX elements to their setup. DMX is simple, easy to use
and can really add a certain exciting element to your lighting environment.
In this document we will explain what DMX is, how easy it is to setup, what you need to control your
lights from your computer and all different things that can be accomplished from DMX. Furthermore,
we will do away with all the rumors of using DMX inside an LOR network and explain just how simple it
really is.
Sit back, pull up a chair and enjoy all the magic that is DMX!
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What is DMX?
We get told constantly that DMX is, “just for the advanced DIY’ers.” After the shock wears off,
we try to explain to people just how easy DMX really is to use. You do not need a degree or have to
understand electronics in any way to understand what DMX really is.
DMX was developed by the United States Institute of Theatre Technology (USITT) in 1986. For
years prior, theater companies had been using many different communication protocols that were not
compatible. This meant that traveling shows and theater groups may not have been able to use
different lighting elements in their show at different theaters. DMX did away with that and created a
standard to be shared throughout the stage lighting industry. What is great about DMX is how easily it
can be adapted by different industries for different lighting controllers.
When people think about DMX, they usually think of expensive, moving lighting fixtures seen on
concert stages and large productions. While DMX is used on those devices that is not what DMX is
limited too. DMX is used every day in non-theatrical interior or architectural lighting. It has been used
to control special effect devices like fog machines and lasers and most recently it has found its way into
the holiday lighting industry.
Let’s get a little complicated
DMX is a standards based RS485 protocol that uses differential signaling along with “packet
based” communication protocols. The protocol is also unidirectional, meaning data can only be sent
from a controller; no information can be returned. Because of this, the protocol does not allow for error
checking or correction within the data stream. It is for this reason that DMX is not used in life
endangering applications.
In a standard DMX setup, there are multiple DMX devices within the network. Each device
features a DMX In and a DMX Out connection port. In the DMX theater world an XLR connection is the
most commonly found way of connection between devices. From the DMX control board (i.e.; DMX
sliders, computers) a XLR cable is connected to the first DMX device into its DMX In port. Another cable
comes out of the first DMX device from the DMX Out port into the next DMX device. The wiring remains
like this throughout the setup. At times there can be a lot of “noise” within a DMX data line, so a
terminator is most commonly found on the last DMX device in the daisy chain. This setup is known as a
DMX Universe.
A DMX Universe can be made up of many different devices that all use a set amount of
channels. (More on that later) However, DMX is limited to a certain amount of channels. DMX512, as it
is commonly known, must fall within the following limits:
-
No more than 512 channels per universe
No more than 32 devices per universe
The network cannot have cabling runs of more than 3,900 feet
Once one of the above 3 rules are met, a DMX Universe is considered “full.”
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A Typical DMX Setup
In a typical DMX setup, there is a controller, known as the “master” and attached devices known
as “slaves.” The controller starts by sending the DMX data to the first device. If that device is meant to
receive the data, the light or controller interrupts the data and then passes the data onto the next
device.
Fig.1
Fig. 1 above shows what a typical theater lighting setup would look like. The DMX controller, in this case
a DMX control board, is considered the master. The three attached lighting devices are considered the
slaves. The orange lines represent the DMX data cables. In this case, the data cables are XLR cables
designed for DMX lighting devices. They have low impedance and can handle complicated DMX lighting
schemes.
Other DMX devices include DMX dimmer packs. These are lighting controllers that can use the
DMX protocol to control non-DMX lighting devices.
Fig. 2
DMX data is interrupted by the controller, which in turn controls whatever devices are attached. These
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do not necessarily need to be lighting devices, but rather elements of a display or setup that need some
sort of control.
Device Address Settings
DMX devices vary in the amount of channels they take up. They can consume as little as 1
channel or they can use all 512 channels available in the network. DMX devices do not receive a “unit
number” rather they start at an address and use the amount of channels that device is slated to use. For
example, many DMX moving lights consume 13 DMX channels. If the first light in the grouping is set to
channel 1, it would than consume 13 channels. That means that the next device in the DMX chain could
only start on channel 14. If that device took up 4 channels, which means that the next device in the
DMX chain would start on channel 19. If that device took up 81 channels, that means the next device
could only start on channel 101.
In the DMX world, there is no unit number. Many people feel as each light should take up a set
number of channels per unit. If you take the above example, people feel that the first moving light
would be unit 1, which consumes 13 channels. The next light would be unit 2, which consumes 4
channels. That is incorrect. Within a DMX network there are 512 available channels and you can use
them as you see fit.
Many DMX devices can use different amounts of channels depending on your settings. The
majority of the time this just means that the more channels you use the more precise you can be in your
movements or color arrangements. An example of this is a DMX pixel setup which would include one
controller that has the ability of two different control functions. The first setup takes all 50 pixels on the
string and gives you individual control of each of those 50 pixels. Each pixel, because they are red, green
and blue pixels, takes up 3 channels. That means that in this mode, each pixel string takes up 150
channels within your DMX network. This same controller also has the ability of making that same pixel
string into one single red, green and blue pixel string. Instead of taking up 150 channels, it now only
uses 3 channels and you no longer have individual pixel control. Another example, listed below, shows
what a standard moving head light can use as far as channel count.
Channel
1
2
3
4
5
6
7
8
9
10
11
12
13
Function
Pan
Pan Fine
Tilt
Tilt Fine
More control over device
Vector Speed (pan/tilt)
Dimmer/Strobe
Red
Green
Blue
Color Macros
Channel
1
2
3
4
5
Function
Pan
Tilt
Shutter
Color Macro
Gobo
Less control over the same
device
Vector Speed (color)
Movement Macros
Fig. 3
Gobo
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DMX and the Holiday Lighting Industry
In recent years, the holiday lighting industry has really started to incorporate DMX into their
environments. For years, there were only a few “accepted” lighting protocols on the market and a lot of
the holiday enthusiasts stuck with the commercially available products. Until recently DMX devices
could not be easily added to holiday lighting displays. However, over the last few years hardware and
software really have made it much easier to add DMX devices to your holiday lighting displays.
The most widely used and commercially available holiday lighting products come from Light-oRama. These controllers rely on a proprietary protocol developed by Light-o-Rama and do not natively
support DMX. However, recently LOR released firmware updates that allow the majority of their
controllers to “speak” in DMX. In 2011 LOR released a major update to their software suit. This update,
amongst other things, added native DMX support and all but did away with the need for the iDMX.
(More on the uses of the iDMX later). The software update added support for several different
commercial and do-it-yourself DMX dongles as well as opened support for using LOR’s already existing
RS485 adapters. This move has created many possibilities when it comes to using LOR’s software,
hardware and DMX devices within the same setup.
What’s different?
While DMX and the LOR protocol are similar, there are a few differences. Before we discussed
the fact that DMX is a unidirectional protocol. LOR’s protocol is bidirectional and supports
communication to and from the devices. LOR’s protocol also has a few speeds in which the data can be
transmitted. Another major difference is the amount of different effects that the LOR network and
controllers can produce. DMX really only supports levels of brightness as well as on and off. Fading and
special effects such as twinkle or shimmer are not natively supported within a DMX network. The final
difference between DMX and LOR’s networks is the wiring configuration. The DMX standard, set by
USITT, states that when category 5 cabling is used, the first wiring pair is where the data is transmitted
(DATA+ and DATA-). This is known as pins 1 and 2. LOR transmits their protocol over pins 4 and 5 of the
cabling. This is going to be important later on.
Effects
LOR light shows are known for dazzling effects that can be created by simply using their
software to add different effects. Many of their effects are generated within their protocol to make
lighting even easier. Such effects include fading, shimmering and twinkling. DMX does not natively
support these effects. However, controllers and different lights have built in effects that take in the data
sent to them and interrupt it into an effect. For example, the LOR twinkling effect is commonly used to
make lights look as though they are strobe lights. A DMX light usually has a strobe effect built into the
light and by varying the data sent to the light will vary the speed of the strobe. If you take a look at the
example in Fig. 3 you will notice that channel 6 of the 13 channel lighting configuration has a
Dimmer/Strobe setting. By varying the intensity on this channel you will change the speed and duration
of the strobe effect.
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The majority of the consumers do not know or want to know what the effects are and are not
supported by their DMX device. Because of this, LOR developed something known as “intelligent
channels.” The iDMX connected into an LOR network can translate the LOR effects into something that
a DMX device could understand. In theory, if you told your DMX device to “twinkle” within the
software, the iDMX would receive that command, translate it into some the DMX device could
understand and send it to the DMX device. The iDMX is limited though, having only 128 intelligent
channels available. This mean if you have 129 non-DMX effects going at once, only 128 of them would
do what they were supposed to be doing.
We noted before that in 2011 LOR released a new version of their software known as S3. This
software natively supports DMX from any computer. In the last section we discussed intelligent
channels. With native DMX support built into the software on your computer, you have an endless
amount of intelligent channels available for use. There is no longer a need to limit yourself to the 128
intelligent channels that the iDMX can produce.
More Wires?
The data transmission is the most important part of the any communications network. Ensuring
that the data gets to the device it should be communicating with is extremely important. While LOR and
DMX can both use cat-5 cabling in their networks, the data parings that they use to transmit the data
vary greatly. If you just plug a DMX device into an LOR device, or vice versa, you will not see much
happening. The wires used for an LOR network and a DMX network are as follows:
LOR Network Wiring
DMX Network Wiring
DATA+
DATA-
DATA+
DATAFig. 4
Why is this important you might ask? Simple! We also noted earlier that the LOR software suite
supports a bunch of different DMX dongles. Several of those dongles are LOR’s own USB based RS485
adapters. To get the DMX data from an LOR RS485 adapter to a DMX device, you need to create a
crossover cable that takes the LOR wiring and connects them to the DMX wiring. To help combat this
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issue, Seasonal Entertainment has released a wiring adapter that converts LOR’s wiring to DMX’s wiring
and makes connection between dongle and device extremely simple. LOR/DMX Wiring Adapter
Let’s talk about the universe
Throughout this article we have been talking about universes. A universe is a grouping of controllers
and lighting devices on one single network. In the majority of LOR shows, you have one single network
that creates a universe. However, if you want to add DMX to your LOR show, you will need to create a
new universe that handles your DMX devices. Why? We have previously talked about the differences
between LOR networks and DMX networks and because of their differences, they do not speak to each
other. (Please note that DMX firmware can be added to all LOR controllers to allow for DMX
communication. However, one of the LOR/DMX Wiring Adapters will be needed when going from an LOR
device to a DMX device, and vice versa.) To combat this, there are several available setups that can be
used to introduce DMX into and LOR setup.
The first setup we will discuss involves using the iDMX in your setup.
Fig. 5
1.
2.
3.
4.
5.
6.
Computer running the LOR Software Suite. In this case you do not need to run S3.
Speakers or radio transmitter for sound.
LOR USB RS485 adapter.
LOR controllers
Wiring pigtails for power connections
iDMX. In this particular setup the iDMX plugs into an LOR universe on one side and creates a
DMX universe on the other side. An XLR3 to Cat-5 cable adapter needs to be used to convert the
iDMX’s XLR connections to cat-5 cabling if you are not using XLR connections on your devices.
7. DMX lights and lighting controllers plug in the iDMX.
8. Rainbow Lights plug into the output ports of the Rainbow Brain.
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In the above example, the iDMX created the DMX network. The iDMX can also be connected to any of
LOR’s mp3 Show Directors. In fact, if you do not use a computer to control your show your only option
for using DMX and LOR devices together is to use the iDMX. In the above example, you do not need any
special LOR to DMX crossover cables. The iDMX interrupts LOR’s protocol and outputs the DMX
protocol.
The next example will show a setup without the iDMX.
Fig. 6
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
Computer running the LOR Software Suite. In this case you need to run S3.
Speakers or radio transmitter for sound.
LOR USB RS485 adapter.
LOR controllers.
LOR supported DMX dongle. Many are supported, in this case the Enttec Open Dongle. (see
below)
Low voltage transformer to power the Rainbow Flood – Extreme’s. XLR5 to Cat-5 adapter
needed here.
Power from transformer to Blender.
Blender for combining power and DMX into one cable. This is only used for Seasonal
Entertainment lights and may not be needed in your setup.
Waterproof extension cables. This is only used for Seasonal Entertainment lights and may not be
needed in your setup.
Rainbow Flood – Extreme’s.
Cabling to additional DMX based lights.
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In the above example, we created two different universes. The first universe was created by an LOR USB
RS485 adapter and handled all the LOR based controllers. The second universe was created by an Enttec
Open DMX dongle and handled all the DMX devices within the universe. At the time of this publication
the following adapters were supported by the LOR S3 Software Suite to create the DMX networks.
With “Raw DMX Protocol
Enttec Open DMX USB
LOR USB485
LOR USB485B
LOR USB485-ISO
With “Enttec DMX USB Pro” Protocol
Enttec DMX USB Pro
With “Lynx” Protocol
Lynx Dongle
From hardware to software
All the above information we discussed deals with setting up the hardware portion of your
setup. However, there is a software side to the setup if you are not using a Show Director and iDMX. In
terms of software, you MUST have the advanced license of the S3 Software Suite. Lower license levels
do not support DMX universes and will not produce DMX commands for your devices to understand.
To begin, you should decide on what adapter(s) you are going to use. This will be very
important later. Next, you need to plug your USB dongle in and allow the Windows operating system to
install the necessary drivers. If you are using Windows XP you may be responsible for installing the
drivers yourself. Always consult with the dongle manufacturer for the proper drivers to use. Once the
drivers have fully installed, you should start up your S3 Sequence Editor. When the editor is open you
will need to either create a new sequence or open and existing sequence. It really is not important
which one you choose, we just need to be able to access the preferences.
Once a sequence is loaded, click on Edit > Preferences > Network Preferences. The following
dialog box will open:
You will notice that all the available Light-O-Rama
Networks, DMX Universes and Additional Networks
are listed here. If you have used the LOR software
in the past, your LOR networks should already be
setup. However, this is the same location needed
to add additional LOR networks and change the
network speeds.
You will notice that 16 DMX Universes are
supported. That means that LOR supports 8192
DMX channels. Before we noted that you would
need to know what dongle you are using. That is
because the protocol the dongle uses will need to
be selected from the “Protocol” drop menus.
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Next you will need to select the adapter you have
plugged in. In our case we have two different
adapters plugged in. The first adapter is an
Enttec DMX USB Pro and the other is an LOR
USB485. Typically the adapter names do not
make much sense but we have found that the
Enttec’s always start with “EN.” On DMX
Universe 1 we want to use the Enttec adapter, so
we would select adapter “EN092697.” (Note that
your adapter names may vary)
Next it is time to select the protocol that the
software will use to interrupt the data it is
receiving. In the table above we listed which
adapters use which protocol. Here is where
that information is applied. Because we are
using the Enttec DMX USB Pro dongle we
would select that as the protocol. However, if
were using an LOR adapter or Enttec Open we
would select the “Raw DMX” protocol. If we
were using the Lynx Dongle we would select
the “Lynx” protocol.
Once you enter in your first grouping of
settings, you can than enter in how ever many
DMX universes you may have. Just select the
adapter you are using and the appropriate
protocol. Another setting you may notice is
the “DMX Listener Port.” This port should be
automatically assigned by the LOR software.
You should not have any issues with what the
software selects. However, if the port is not
automatically filled in it is best to contact an
Light-O-Rama support member.
Now your DMX network is fully setup. One nice feature of the LOR Sequence Editor is the ability to
“Control Lights” directly from the editor. However, the software does not really speak DMX. It requires
that a “listener” listen for the DMX commands and translate them. There really is nothing you need to
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do besides start the Light-O-Rama Control panel. You will notice that a DOS window will open and
display some key things.
When the LOR Comm Listener opens you will see that it searches for the adapters in universe order. It
will first open up those adapters and than accept a connection. It will do this on all the DMX universes
you setup. Notice at the top the port what the listener is “listening” too. This is what was listed in the
Network Preferences. As long as your Control Panel is open, this program will remain running. You
currently can minimize it but it cannot be closed without exiting the LOR Control Panel. The program
needs to be running in order to “Control Lights” from the sequence editor.
How much will it cost?
Many people using DMX in their holiday light setups really are doing so on a very limited budget.
The cost really can become a concern to many people. However, with all the options that LOR offers in
terms of DMX dongles, it really is becoming much more cost effective for the majority of people to add
DMX to their setup. Below is a chart we put together of the cost associated with the different dongles
that are currently supported. This seems to change often as LOR continues to support more and more
adapters, so this list could be out of date, but we will try our best to keep it updated.
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Components Needed
Enttec USB DMX Pro
XLR5 to Cat-5 adapter
Do-It-Yourself
No
Total:
Cost
$151.00
$14.99
$165.99
Enttec USB DMX Open
XLR5 to Cat-5 adapter
No
Total:
$60.00
$14.99
$74.99
LYNX Dongle Parts
LYNX Dongle PCB
LYNX Dongle Enclosure
Yes
Total:
$45.66
$6.00
$10.00
$61.66
LOR USB485
Seasonal Entertainment Adapter
No
Total:
$27.95
$10.99
$38.94
LOR USB485B
Seasonal Entertainment Adapter
No
Total:
$42.95
$10.99
$53.94
LOR USB485-ISO
Seasonal Entertainment Adapter
No
Total:
$98.95
$10.99
$109.94
Just remember that the Lynx Dongle is 100% a do-it-yourself kit. It has no warranty, it is not insured and
you are left at the mercy of the members of the DIYLightAnimation.com forums for assistance. It
sometimes can take extended amounts of time to hear back from the owner of that site. Furthermore,
should something happen to ruin or harm your devices or computers, there is no sort of protection for
the consumer in the unlikely event something should happen. Using the Enttec and LOR dongles
guarantees you support from commercially available suppliers with years of knowledge and experience
with their products. Furthermore, in the case of the LOR adapters, many people may have a spare lying
around their desk just asking to be used but if you do not, it is by far the cheapest and easiest way of
adding DMX to your setup.
The loose ends
We have spent the majority of the time talking about the use of DMX and LOR together. Don’t
forget that there are other software programs on the market today that also allow for a mix of
networks. The people of GraphXPros, Inc have created their own software suit known as Light Show
Pro. It is currently in its second version and allows users to mix a whole mix of lighting protocols. It
supports the use of DMX, LOR, d-Light, X-10, Renard, Animated Lighting and Lynx hardware. There are
many different thoughts and theories on the software however it seems that the general consensus is
that the software still has a long way to go before it is fully useable. The software editor can be slow
and difficult to navigate. It is based on the Vista Interface Styling and uses different tabs for the
selection process. We have tested and used it and while it does some exciting things it is not, at least in
our opinion, at the level that the LOR software is in terms of reliability.
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Another exciting piece of software that is out there is called xLights. This is a free, open source
piece of software that really allows the user to continue to use whatever sequencing software they are
used to using. By assigning different COM ports to do different things in xLights, you can mix a whole
host of protocols together to create dazzling light shows. There is even development of a new and
exciting sequence editor that the folks behind xLights are working on. Again, we have tested and used
the software and like it. Like we said, it is open source based and they have also teamed up with the
owner of DIYLightAnimation.com so it can become tricky to get support or answers to your problems in
a timely manner. However, if you are happy with your current software and do not want to learn
something new, xLights is a great choice for the enthusiast.
Finally, the old workhorse for the holiday lights enthusiast, Vixen. This software is tried and
tested by many thousands of people and is really loved and enjoyed by the majority of them. Once
again this software is open source based however we have found the creator to be extremely helpful
and always around when you need a question answered or a problem solved. Furthermore, Vixen 3.0 is
in the works. It is a complete redesign of the previous version 2.5 and the features that are expected to
be added are extremely promising. As the software comes out we will be sure to visit it and fully test it
and report back our findings.
Let the games begin
That’s it! You have done it! You have successfully added a DMX network (or several DMX
networks) to your LOR lighting display. Wasn’t that simple?
In all seriousness, adding the networks to your display really is simple and easy to accomplish.
There is no need to worry about expensive parts or do-it-yourself products. Let this be a lesson to
everyone that the myths that are floating around are truly just that, myths. DMX devices and products
can take your displays and lighting setups to whole new levels. Now is the time to enjoy a mix of
industry standard protocols and create a musical and lighting extravaganza unlike anything you could
have dreamed…….Entertaining the world through light and sound!
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