Designers Lighting Forum
DMX-512A FOR LED CONTROL:Getting Reacquainted With an Old/New Friend
Shoshanna A. Segal, CLD, IALD, LEED APBD+CMarch 29, 2017
Credit(s) earned on completion of this course will be reported to AIA CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.
This course is registered with AIA CESfor continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any
material of construction or any method or manner ofhandling, using, distributing, or dealing in any material or product.___________________________________________Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
LearningObjectives
1. Why a standards based system is a good idea
2. The basic organization and function of a DMX-512A System
3. How DMX-512A can be a useful tool in an architectural environment
4. Requirements and terminology for specifying DMX-512A system
At the end of the this course, participants will be able to:
Topics we will not cover today….Earl Simmons, American rapper, record producer, and actor
… or thisReebok’s proprietary foam compound used to provide cushioning and shock absorption in basketball shoes
WHAT IS IT?
• a method of digital data transmission between controllers and controlled lighting equipment and accessories, including dimmers and related equipment.
• intended to provide for interoperability at both communication and mechanical levels with controllers and receivers made by different manufacturers.
BASIC DEFINITIONS
• Original Title –• USITT DMX512 -
ASYNCHRONOUS SERIAL DIGITAL DATA TRANSMISSION STANDARD FOR CONTROLLING LIGHTING EQUIPMENT & ACCESSORIES – NOW
• ANSI E1.11-2008 (R2013) ENTERTAINMENT TECHNOLOGY
• USITT DMX512-A ASYNCHRONOUS SERIAL DIGITAL DATA TRANSMISSION STANDARD FOR CONTROLLING LIGHTING EQUIPMENT & ACCESSORIES
DMX512-ABUSDAISY CHAIN256512
BASIC HISTORY
• Developed in 1986 by USITT• Standard transferred to ESTA Technical
Standards in 1998
Why A Standard?
• Having a standard ensures that everyone using the specific technology is complying with the same set of rules. In this case that means…
Electrical Interface Standards• EIA485 (RS485)
Physical Interface Standards• 5-Pin XLR Connectors
Interface Standards• 8 pin modular or RJ45
Connectors
Topology Standards• MULTI-DROP BUS
TOPOLOGY WITH • DAISY CHANINED
NODES • ELECTRICAL
TERMINATION
BASIC DEFINITIONS
TOPOLOGY STANDARDS• An electrical scheme to carry power
or data• A bus can be Class I (Signal travels
with Line Voltage) • or Class II (Limited power, often 48V
or Less)• A bus can be rated (or limited) by
distance or cable length for signal/power – as in the 1500’ mentioned in the RP
• The rating of bus components affects the rated distance among or between components (nodes) for signal/power
• A bus can carry Digital or Analog Communication
DMX-512-A
BUSDAISY CHAIN256512
BASIC DEFINITIONSDMX-512-ABUS
DAISY CHAIN256512
TOPOLOGY STANDARDS
TOPOLOGY STANDARDS
THIS
NOT THIS
BASIC DEFINITIONS
• DMX-512-A breaks down the control process into 256 digital steps.DMX512-A
BUSDAISY CHAIN
256512
BASIC DEFINITIONS
• 512 REPRESENTS THE MAXIMUM NUMBER OF ADDRESSES OR DATA SLOTS AVAILABLE WITHIN ANY SINGLE DMX512 UNIVERSE
• EACH OF THE 32 NODES ON THE BUS CAN BE INDIVIDUALLY CONTROLLED BY SENDING INSTRUCTIONS TO EACH OF 16 ATTRIBUTES.
• 32 x 16 = 512
DMX512-ABUSDAISY CHAIN256
512
How is all of this used?
Lighting Control ComponentsAll lighting systems have essentially the same components:• User-Command/Sensor/Controller/
Dimmer/Switch• Interface - translates signal to
action• Power• Regulator-
Driver/Ballast/Transformer• Light Source/Luminaire/Light
Engine
Lighting Control ComponentsAll lighting systems have essentially the same components:• User-Command/Sensor/Controller/
Dimmer/Switch• Interface - translates signal to
action• Power• Regulator-
Driver/Ballast/Transformer• Light Source/Luminaire/Light
Engine
Lighting Control ComponentsAll lighting systems have essentially the same components:• User-Command/Sensor/Controller/
Dimmer/Switch• Interface - translates signal to
action• Power• Regulator-
Driver/Ballast/Transformer• Light Source/Luminaire/Light
Engine
Lighting Control ComponentsAll lighting systems have essentially the same components:• User-Command/Sensor/Controller/
Dimmer/Switch• Interface - translates signal to
action• Power• Regulator-
Driver/Ballast/Transformer• Light Source/Luminaire/Light
Engine
Lighting Control ComponentsAll lighting systems have essentially the same components:• User-Command/Sensor/Controller/
Dimmer/Switch• Interface - translates signal to
action• Power• Regulator-
Driver/Ballast/Transformer• Light Source/Luminaire/Light
Engine
How do we communicate with the light source?
0-10V
PHASE CONTROL
PWM
0-10v systems
• Line voltage switches the driver “on”
• Low voltage provides a control signal indicating a percentage of maximum output
• Voltage drop is an issue as the control signal is weakened as it travels
• May result in output differences along a single control run
• 0-10v is an analog control protocol and it interfaces with the LED Driver with 2 sets of wires
• Class I 120/277 line-voltage switching
• Class II ≤48v dimming control
ANSI C82.11 vs. ESTA E1.3
ANSI C82.11• CURRENT SINK• DRIVER PROVIDES CONTROL
VOLTAGE• DIMMER IS PART OF DRIVER• MAX OUTPUT AT ≥10V• MINIMUM OUTPUT AT 1V• MAY REQUIRE ADDITIONAL
“OFF”• MAX # OF DRIVERS/CONTROL
LIMITED BY DRIVER CAPACITY
ESTA E1.3• CURRENT SOURCE• CONTROL PROVIDES VOLTAGE
FOR EACH CHANNEL• DIMMERS ARE SEPARATE FROM • MAX OUTPUT AT 10V• OFF AT 0V
Phase Control Systems
• Modulates the amount of time full voltage is applied
• 120 times per second
• 2x frequency is delivered via AC (60Hz)
Forward Phase
Also called Leading Edge
Reverse PhaseAlso called Trailing Edge
Pulse Width Modulation• Controls the time-averaged
current through an LED and therefore the intensity.
• LED is turned on and off more quickly than is perceptible to the human eye. The intensity is approximately proportional to the percentage of time that the LED is on.
• Because it can control individual LED’s PWM can be used for color mixing as the relative levels of each component color can be manipulated to achieve the desired color.
Why these are non issues with DMX512-A?
Why these are non issues with DMX512-A?
DMX-512A
PROS• Stable protocol designed to
make products from different manufacturers work together; refined and reapproved for over 30 yrs.
CONS• “Old Technology”
DMX-512A
PROS• Stable protocol designed to make
products from different manufacturers work together
• Less gray area than other methods – presence of a written standard means you either comply or don’t
CONS• “Old Technology”
• Requires “special” equipment
DMX-512A
PROS• Stable protocol designed to make
products from different manufacturers work together
• Less gray area than other methods –presence of a written standard means you either comply or don’t
• Technology designed for mission critical live performance
CONS• “Old Technology”
• Requires “special” equipment
• Not every conference room needs this
DMX-512A
PROS• Stable protocol designed to make
products from different manufacturers work together
• Less gray area than other methods –presence of a written standard means you either comply or don’t
• Technology designed for mission critical live performance
• “Old school” nature of the standard means relatively few places to look when problems do arise
CONS• “Old Technology”
• Requires “special” equipment
• Not every conference room needs this
• No inherent error checking, communication is unidirectional
DMX-512A
PROS• Stable protocol designed to make
products from different manufacturers work together
• Less gray area than other methods –presence of a written standard means you either comply or don’t
• Technology designed for mission critical live performance
• “Old school” nature of the standard means relatively few places to look when problems do arise
• Wireless DMX
CONS• “Old Technology”
• Requires “special” equipment
• Not every conference room needs this
• No inherent error checking, communication is unidirectional
• “But I want wireless”
This concludes The American Institute of Architects Continuing Education Systems Course