# How do you make a DMX terminator?



## Thelightinggal

So, I have always wondered this, how do you make a DMX terminator? Is there a guide, or does someone here know? I want to know how to make them...thank you!


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## jstroming

Get a male 5-pin or 3-pin xlr connector, and put a 120ohm resistor (available at radio shack) between pins 2&3.


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## jstroming

PS when I say "put" I mean solder, assuming your using a solder xlr connector. that's it, nothing tricky at all.


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## chausman

This thread ([thread]15337[/thread]) has some useful links as well. 


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## Thelightinggal

OK so...if DMX is 5 pin, why would you use an xlr 3 pin, it wont fit into the DMX spot on the moving light then, right?


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## gafftapegreenia

Thelightinggal said:


> OK so...if DMX is 5 pin, why would you use an xlr 3 pin, it wont fit into the DMX spot on the moving light then, right?


 
Some older equipment, as well as modern DJ grade equipment use 3 pin connectors since pins 4 and 5 are not typically used in most DMX applications.

While you're at it, make yourself a tester too!http://www.bigclive.com/dmxtest.htm


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## Thelightinggal

gafftapegreenia said:


> Some older equipment, as well as modern DJ grade equipment use 3 pin connectors since pins 4 and 5 are not typically used in most DMX applications.


 
AH makes sense, now for another question..what are pins 4 and 5 used for when they are used? Just trying to understand as much as possible....


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## Les

Thelightinggal said:


> AH makes sense, now for another question..what are pins 4 and 5 used for when they are used? Just trying to understand as much as possible....


 
There really never has been a "standard". In the past, it has carried a "dimmer overtemp" signal other related events designed to give feedback to the board operator. In my understanding, DMX 4 & 5 have been a "free for all", except in cases where those pins carry power, which I believe is highly discouraged. 

3-pin DMX is just designed to cut the costs where they aren't being utilized. Several companies make adapters so you can use 5-pin cable for 3-pin lights and vise-versa (as long as those conductors aren't being used).


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## TimMiller

Most commonly pins 4 and 5 are for a second universe. Avolites consoles make this standard then they have an adapter that splits it out into 2 separate lines.


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## Thelightinggal

Les said:


> There really never has been a "standard". In the past, it has carried a "dimmer overtemp" signal other related events designed to give feedback to the board operator. In my understanding, DMX 4 & 5 have been a "free for all", except in cases where those pins carry power, which I believe is highly discouraged.
> 
> 3-pin DMX is just designed to cut the costs where they aren't being utilized. Several companies make adapters so you can use 5-pin cable for 3-pin lights and vise-versa (as long as those conductors aren't being used).



Thank you!! One more question for you, what is a dimmer overtemp signal?


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## Les

Generally, an LED or text signal on the display indicating that the dimmers are exceeding their maximum allowable operating temperature (usually caused by airflow restrictions at the dimmers, or a failure of the HVAC system in the dimmer room). Failure to resolve the problem could result in the dimmers auto-shutting down to prevent damage (best case scenario).

Could also indicate a fan failure in one of the dimmer racks, but usually the unit will fail to operate as a safeguard until such an event is rectified.

I hadn't heard about the second universe designation. I had always been under the impression that DMX 4 & 5 were for reporting/feedback purposes.


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## derekleffew

There's a thread on this, use the search. Pins 4&5 have never had any widespread use, and very, very likely never will, as the industry is slowly (molasses in Maine in January slowly) moving to other protocols. As for use as an additional universe, this use was specifically forbidden in the most recent revision of the standard, ANSI E1.11 2008.

As for talkback, when I posed the question earlier if anyone knew of a manufacturer that used pins 4&5, there was only one satisfactory response, which may now be obsolete. (Is ET still in business? Why does every link on http://www.etdimming.com/index.php?src= require a User Name and Password? Seems to me they don't appear to want to advertise their wares or sell anything.)

As for dimmer overtemp indication, IIRC, Berkey Colortran did use those pins for that purpose on some, but not all, systems that used CMX/D192/Dimension5. Perhaps Teatronics also? I think Strand Century made the user run another TA4 cable if one wanted overtemp indication from a CD80.


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## chausman

derekleffew said:


> As for use as an additional universe, this use was specifically forbidden in the most recent revision of the standard, ANSI E1.11 2008.


 
Do you know why it was forbidden?


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## derekleffew

More info on original topic at wiki entry Terminator, DMX.


chausman said:


> Do you know why it was forbidden?


http://www.controlbooth.com/forums/lighting-electrics/21566-dmx-5-pin-3-pin.html#post191872


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## dramatech

derekleffew said:


> (Is ET still in business? Why does every link on Entertainment Technology require a User Name and Password? Seems to me they don't appear to want to advertise their wares or sell anything.)



Derek, I don't know that I have the answer, but I have some clues that might help. ET (Entertainment Technology) was as far as I know, the first to use IGBT dimming. Some of their early products would automatically determine if the load would work better with forward switching or reverse phase switching of the sinewave.
I recently purchased one of their very early products off of ebay, I found the manual on line and downloaded it. By using IGBT technology, it does not require, and does not have choke coils or breakers. There are very complex circuit boards for each channel of dimming. Each board has it's own microprocessor and determines it's own zero crossing.
Even though it states in the manual, that it is to run on three phase power, I have it running with 4 channels on one phase and 2 channels running on a second phase of a three phase system. ( And for those of you that worry, I do have seperate neutrals running to each group of 2 dimmers.)
It states very clearly in the manual, that pins 4&5 are for feedback to it's priority controller. It goes on to explain the many functions that will be monitored.
Now what I found to be curious. The address of ET on the back of the dimmer pack is in Oregon. More recently, a company of the same name and selling the same technology is in Texas.
About 10 months ago, I purchased a single channel dimmer off of ebay that uses the same IGBT technology. It was labeled as a Strand, but when the label tape was pulled off, it was an ET unit from the Texas address.
As we know, over the recent few years, Phillips has been buying up entertainment lighting companies. Color Kinetics, Selecon, Strand and varilite were all purchased with a lot of announcments, and all of their US offices moved to Texas. I am not sure, but believe that they are in or near the old ET facilities in Texas. Also, Strand now has dimming technologies that were clearly ET developments. Although I didin't see any anouncements of purchase, I have to believe that ET is now part of the Strand division of Phillips. If that is the case, I think that I will look more seriously at Strand dimmer racks in the future, when considering a new purchase.
I know this is all a little disjointed, but might lead to what happened to ET, and explain at least one manufacture that used pins 4&5 in the past.

Tom Johnson


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## derekleffew

dramatech said:


> ...Although I didin't see any anouncements of purchase, I have to believe that ET is now part of the Strand division of Phillips. ...


I can help fill in some of those blanks. Van will no doubt fill in the rest. (It's a short but sordid history, and similar to, but much more convoluted than ColorTran, Berkey Colortran, LEE Colotran, NSI Colortran, Leviton.)

ET was originally sold only by Rosco, starting in 1995? 
The agreement ended in ? and ET was its own company. 
At some point I believe ET merged with Horizon Controls.
One of the non-working links on the ET site above is titled "Philips Completes Acquisition of Genlyte, 1.29.08.
You may recognize Genlyte as the purchaser of Vari*lite in 2002, and other semi-familiar brands such as Lightolier, Stonco, and Bronzelite.
At LDI 2008, I asked the ET booth, "Why do you have the Marquee console here, and across the aisle is Strand's Palette and LightPalette lines, both being derived from Horizon Controls?" They answered, "Honestly, we're asking ourselves that same question."
More is probably at the collab article, Memory Lighting Control Systems, History - ControlBooth , but I haven't time to check.

As for the pros and cons of dimmer, IGBT , see the thread http://www.controlbooth.com/forums/lighting-electrics/9344-sensor-vs-et-intelligent-raceway.html .


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## Lotos

derekleffew said:


> I can help fill in some of those blanks. Van will no doubt fill in the rest. (It's a short but sordid history, and similar to, but much more convoluted than ColorTran, Berkey Colortran, LEE Colotran, NSI Colortran, Leviton.)
> 
> ET was originally sold only by Rosco, starting in 1995?
> The agreement ended in ? and ET was its own company.
> At some point I believe ET merged with Horizon Controls.
> One of the non-working links on the ET site above is titled "Philips Completes Acquisition of Genlyte, 1.29.08.
> You may recognize Genlyte as the purchaser of Vari*lite in 2002, and other semi-familiar brands such as Lightolier, Stonco, and Bronzelite.
> At LDI 2008, I asked the ET booth, "Why do you have the Marquee console here, and across the aisle is Strand's Palette and LightPalette lines, both being derived from Horizon Controls?" They answered, "Honestly, we're asking ourselves that same question."
> More is probably at the collab article, Memory Lighting Control Systems, History - ControlBooth , but I haven't time to check.
> 
> As for the pros and cons of dimmer, IGBT , see the thread http://www.controlbooth.com/forums/lighting-electrics/9344-sensor-vs-et-intelligent-raceway.html .


 
I had to dig through my email to find the press release... But I believe that ET and Horizon Controls are now de-merged...
Acuity Brands, Inc. - Investor Relations - News Release


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## DaveySimps

As someone with install of over 400 ET dimmers and running Horizon, I can tell you that they split a long time ago. I recently had occasions to contact Horizon tech support after the recent sale, they are no longer providing support at all. I believe ET dimmers are no longer available. I have recently had to have 2 repaired. After an 11 week turn around, they came back with a return address with a Strand contact.

~Dave


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## Van

DaveySimps said:


> As someone with install of over 400 ET dimmers and running Horizon, I can tell you that they split a long time ago. I recently had occasions to contact Horizon tech support after the recent sale, they are no longer providing support at all. I believe ET dimmers are no longer available. I have recently had to have 2 repaired. After an 11 week turn around, they came back with a return address with a Strand contact.
> 
> ~Dave


 It's been a whiloe since I was in contact with any of the folks at ET. I was an ET feild tech for several years, specificallyt for Horizon and Vista control systems and for all forms of IPS < Intelligent Power Systems> Dimmers. They did have a couple of addresses in Portland. It's possible tht if you have dims with and "Front St. " address I might have assembled them. After The Phillips / Genlyte deal I lost track of Gordon. I should probably email him just to stay in touch. Gordon Pearlman who was the president / owner of ET seemed to keep moving around with the company. When they merged with Rosco, he kept the company here. When Genlyte bought them they wanted the whole kit and kaboodle in Texas. < No, Thank you. I do not wish to move there again.> After that I would occasionally see Gordon at ART functions and he would cryptically say things were really cooking at Genlyte. That's all I really know. 
Except that is important to remeber that Gordon and his team invented the first Memory board, and he developed DMX. < or the original standard> 
It has changed somewhat over the years. I would have to go back and dble check my manuals but my recollection was that the over temp signal was not carrried on 4/5, as gordon wrote the protocol and his protocol said 4/5 weren't used..... But it's been a long time and I've been laminating all morning.....


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## danhr

Here's a link with a neat DMX tester/terminator. It's cheap to make (so you can make several) and cool to watch! I keep one on a lanyard with my homemade gamchecks and also on the end of the DMX chain to verify operation. 
Make a DMX tester.


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## gafftapegreenia

Is a combined tester/terminator, with a 120 ohm resistor, as well as two LED's, across pins 2 and 3, still as effective as a stand alone 120 ohm terminator?


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## icewolf08

gafftapegreenia said:


> Is a combined tester/terminator, with a 120 ohm resistor, as well as two LED's, across pins 2 and 3, still as effective as a stand alone 120 ohm terminator?


 
Indeed it is. As long as you have that resistor it will function as a terminator.


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## gafftapegreenia

Thanks, its just something thats been tuggin' at the back of my mind for a while.


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## derekleffew

Van said:


> ... Except that is important to remember that Gordon and his team invented the first Memory board, and he developed DMX. < or the original standard>...


I don't mean to make light of Mr. Pearlman's achievements, but both of these statements are highly debatable. Read _The Speed of Light_, by Linda Essig, in which she interviews Gordon and many other luminairies of our industry (some of whom are CB members ).

EDIT: On the SML, Mitch Hefter writes that Entertainment Technology (ET) is alive and well, but currently concentrating on control of architectural lighting rather than stage/studio. It makes sense--Philips doesn't need a bunch of companies all doing the same thing and thus competing with one-another. No word as to why their website is fubar.


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## Jakob B.

To make a 4-Pin DMX Terminator, do you still solder the 120 Ohm resistor between pins 2 &3? I want to make some for our Rosco I-Cues.


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## GreyWyvern

Jakob B. said:


> To make a 4-Pin DMX Terminator, do you still solder the 120 Ohm resistor between pins 2 &3? I want to make some for our Rosco I-Cues.


Yes, that is correct.


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## icewolf08

Jakob B. said:


> To make a 4-Pin DMX Terminator, do you still solder the 120 Ohm resistor between pins 2 &3? I want to make some for our Rosco I-Cues.


But really, with 4-pin devices you should have a return run to the PSU from the output of the last device in the chain. This not only provides termination for the DMX, but also helps maintain the correct operating voltage for the devices.


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## coldnorth57

Alway rember to loop your 4 pin back to powersupply


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## BobHealey

coldnorth57 said:


> Alway rember to loop your 4 pin back to powersupply



That assumes the power supply both supports and has the connectors to do so.


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