[SML] 0-10V dimming on ETC Sensors

[David Fox]

LONG AND SLIGHTLY COMMERCIAL REPLY
"Standard" can be confusion as there are two different standard methods of accomplishing 0-10V dimming in LED fixtures these days. 
The first is Sink and the other is Source. 

In Sink, the LED driver receives a switched source of line voltage and when energized SENDS 10VDC down the Data + and Data Common lines. A device such as ETC's Response 0-10V gateway uses internal circuitry to pull the voltage down in conjunction with an incoming DMX or sACN signal. The driver measures resistance on the line and dims output to the fixture accordingly. A driver designed for 0-10 SINK is full when it measures no resistance and at its minimum output when it measures full resistance. If the data lines are open, the driver outputs full. (THIS IS A SIMPLIFIED EXPLANATION)

In Source, the LED driver receives a switched source of line voltage and control voltage via the Data+ and Data common lines. It can also use a device like ETC's Response 0-10v gateway. When the Driver is energized it LOOKS for voltage on the data lines. As it RECEIVES control voltage it will dim up from its minimum level to full. Again 10VDC is full and 0VDC is minimum level. If the data lines are open, the driver outputs minimum level. 

In answer to your question, the sensor rack can be configured to provide the switched source of power to the drivers, ( I recommend using Switched mode over Non Dim mode and setting the threshold to 1%), but can not sink or source the control voltage. 

There are multiple products on the market that can do this. I am biased, and like the ETC 0-10V Response Gateway (I know.. such a surprise right?). It supports both source and sink and it's outputs are fully addressable. 

I suspect the fixture you linked to is SINK as that is the more common of the two standards. 

Second is to remember that 0 volts is not off but the minimum level the driver produces. Off in these pieces of equipment is on loss of power not control. This has caused some confusion in the industry by people expecting that bringing them to 0 turns them off.  You can resolve some of this in the way you handle addressing and by setting profiles. 

Lastly, the percentage on the driver is based on output as measured by a full spectrum light meter not the human eye. In other words, turn the driver on to full and measure lumens. The printed percentage of that is your minimum level. This measured level is going to be different than what the human eye perceives as our eyes are developed to allow more light as it gets darker. So while a meter may read 10%, your eye will perceive about 23%.

Setting actual expectations with these can sometimes be harder than actually controlling them. 


If you have more questions, feel free to contact me directly.
David Fox
ETC
Training and Documentation Specialist
888-908-2193