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DMX Adapters; Another 5 pin to 3 pin DMX question

Discussion in 'Lighting and Electrics' started by RichMoore, Jul 15, 2008.

  1. RichMoore

    RichMoore Member

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    I have seen in previous posts regarding 5 pin to 3 pin DMX conversion questions, to just use the first 3 pins on the 5 pin to connect to the 3 pins of the XLR connector, since the 4th and 5th pins were vacant or not used at all.

    Since my in-house DMX uses all 5 pins of the connector and the cable is 2 twisted pairs with braided shield, how would I connect to the 3 pin connector? I have tried using only one of the twisted pairs with no luck. I am thinking that I need to use the positives of each pair and the negatives of each pair to connect to pins 3 and 2 with the shield still on pin 1.

    Does that make sense? Has anyone else done this? Am I way off base? What is the solution?
     
  2. waynehoskins

    waynehoskins Active Member

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    Both pairs are a differential RS-485 serial data channel. You can't common them to each other.

    Data Channel 1 is the one that's used for outbound control data. That's pins 2 and 3 (2 data complement, 3 data true) .. backwards from the audio wiring convention.

    What are you trying to hook up to what? It's possible (nay, probable) that the 3-pin device isn't DMX.
     
  3. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    By "in-house DMX," to what are you referring? The cabling? All DMX512A-compliant devices only use pins 1,2,3 of the 5pin XLR. All devices using 3pin XLR to carry DMX, while technically non-compliant, should have no issues provided the adapters are wired one-to-one. Note that early Martin gear (i.e., PAL-1200s) and a few others required pins 2&3 to be swapped.

    Here is the current DMX standard: ANSI E1.11 - 2004, and here is a link to adapters I have found useful: Audiopile.net.
    [​IMG]

    What are you trying to control, and with what?
     
    Last edited: Aug 14, 2010
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  4. ishboo

    ishboo Active Member

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    I have a 5-pin DMX-512 board and a couple devices that are 3-pin. I picked up a couple adapters on ebay for about $3/ea and haven't had a single problem since.
     
  5. TimMiller

    TimMiller Well-Known Member

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    In many installed they will wire up pin's 4 & 5 but they are not physically used. Using turn arounds will not cause any problems.
     
    Last edited: Jul 16, 2008
  6. porkchop

    porkchop Well-Known Member

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    I have to agree with Derek totally. In theory (although as mentioned it's against the standard) all you need is pins 1-3. Your house wiring may be 5 wire but as far as you board's output is concerned pins 4 and 5 are basically vacant of useful information. There are exceptions to this, the pyro I work with uses what we call "true 5 pin DMX" that is 5 wire cable that sends two sets of information so as to provide error checking (or something like that haven't truly looked into it), but as far as the standard is concerned that is not really DMX, that's an offshoot that uses some similar equipment. If you're using modern lighting gear that takes 3 pin information it shouldn't matter that you actually have 5 pins in your house system.
     
  7. RichMoore

    RichMoore Member

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    A bit more info and hopefully clarification on my issue.

    I am running a Strand 520i....into which, I wrote the attributes of the new fixtures into the fixture library....red, attribute 14...green, attribute 15...blue, attribute 16....

    My DMX cabling is 2 twisted pairs with braided shielding soldered to pins 1 thru 5 on 5 pin connectors....

    All DMX signal goes through Path Port/ethernet....

    I have been provided with 7 LED Par type units which have 3 pin DMX input and output connections....

    I have been provided with 3 pin male & female connectors and with 5 pin male and female connectors, along with cable that is 2 twisted shielded pairs...

    I am fabricating cables to daisy chain the LED units in order to control the color output of the fixtures....

    I have taken a short 5pin DMX cable and cut it, so that I have a male with a short length of 2 twisted shielded pairs and a female with a short length of 2 twisted pairs....

    I soldered into the1, 2, and 3 pins of 3 pin connectors the twisted pair and the shield that are connected to the 1, 2, and 3 pins of the 5 pin connectors....

    I then connected the 5 pin male into the PathPort output and connected the 3 pin female into the LED 64unit DMX input....then I connected the 3 pin male into the LED 64unit DMX output and inserted a DMX terminator into the 5 pin female...

    Using the rotary controls on the 520i, I was able to only control the red output of the fixture, and that went from red to black.

    I am presuming that the simple way around this issue is to try the store bought 5 to 3 converters, but seeing as how I am an old poot, I know there must be another way, although not quite so simple.

    Any ideas or not so simple solutions?

    Thanks,

    Rich Moore
    Technical Coordinator
    Performing Arts Center
    Texas A&M--Corpus Christi
    Corpus Christi, Texas
     
  8. waynehoskins

    waynehoskins Active Member

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    Me believes your problem is not in the adapter. If you were able to control anything about the fixture, there's data getting to it, and it's just RS-485, so if it was able to make out anything of the control signal, then it's probably good.

    Methinks your problem is either in the fixture addressing or the library in the board.
     
  9. RichMoore

    RichMoore Member

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    Thanks for the response Wayne.

    I will revisit the fixture library and double check what I have written.

    I am now wondering about the dip switches on the back of the LED 64units. I may have inadvertently juxtaposed the #10 switch with the #1 switch. I will give that a shot also.

    Thanks again,

    Rich
     
  10. JD

    JD Well-Known Member

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    Also check for dyslexia !

    More than once I have ended up with 2 & 3 reversed even though I was positive I did it right! When the dmx is reversed, you get some odd behavior, not quite dead, but nothing like normal.
     
  11. Banquo

    Banquo Member

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    I ran into this problem with some Abstract Twister4's, before the pins were swapped only one of the three available fixture attributes worked.

    If your fixture library and addressing checks out, it could be that you need to do this for your LED Pars. If you can identify the make and model, you should be able to find a pdf manual that shows the correct pin out.
     
  12. RichMoore

    RichMoore Member

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    I think that my original issue is solved.

    waynehoskins was correct, in that the problem was in the addressing of the fixtures.

    I found the Sabre Technology Dip Switch Calculator and used it and now all is well. I don't recall whether or not someone turned me onto this site or not, but here it is and it works like a champ.

    Sabre Technology - Dip switch calculator

    I am using my 5 pin to 3 pin cable that I cobbled together to get the DMX signal into the first fixture and then daisy chaining 3 pin to 3 pin putting the fixtures together.

    Thanks for all of the help and ideas.

    Rich
     
  13. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    For times when a computer and/or the Internet is not available, (hey, it could happen,:rolleyes:) I've found this chart to be valuable. Although it says Martin Atomic Strobe, it will work for almost everything, except High End gear and a few minor others. And I had it first, before Chauvet!
     
  14. w3st0n21

    w3st0n21 Active Member

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    DMX adapters

    Hey guys,
    how do i make an adapter to go from 5 pin (m) to 3 pin (f)? i have the connectors, so i just need to know what pin numbers go to what wires and what not.

    thanks
     
  15. abbyt

    abbyt Member

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    Re: DMX adapters

    On both connectors=
    Pin 1 = Pin 1
    Pin 2 = Pin 2
    Pin 3 = Pin 3

    I have seen pins 4 and and 5 handled two ways. I've seen the wires completely disconnected and capped off (with a piece of heat sink) on both ends (the way I recommend) and I have also seen them left connected at the 5 pin side, and disconnected only on the 3 pin side.

    Whether it is the 5 pin or 3 pin connectors, the pins should be numbered. Remember if you're wiring a male to a female (or vice-versa) the connectors are a mirror image of each other.

    DMX Pinout standard is as follows:
    1= Common
    2= Data -
    3= Data +
    4= Unused (sometimes has wire connected, sometimes not- depends on who made the cable)
    5= Unused (sometimes has wire connected, sometimes not- depends on who made the cable)

    Is that the info you were looking for?
     
  16. w3st0n21

    w3st0n21 Active Member

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    Re: DMX adapters

    exactly! thank you very much
     
  17. derekleffew

    derekleffew Resident Curmudgeon Senior Team Premium Member

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    The three posts immediately above have been merged into this thread, from one originally titled "DMX Adapters." For iPhone/iPod Touch owners, there are a couple of dipswitch calculators at the iTunes Store. My favorite of these is iSwitchDMX, by Mike Zinman (and his PocketLD app is excellent, second only to my Excel Photometric Workbook ;). Amazingly, the two agree on almost all calculations :)).
     
    Last edited: Feb 11, 2009
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  18. JD

    JD Well-Known Member

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    I think the 3 to 5 questions are eternal because what you see flies against common sense!

    Warning: The following is non-standard and stuff only JD likes to do!

    I like the double pair cable because you can actually make break-out cables and use the other pair to run com to the stage, or as a second Universe. (Here come the digs!) Oh well, just me. Of course four channel snake cable is the best! Audio snake cable is made from multi-channel shielded pair data cable and has the 120 ohm impedance DMX likes. (Check out the Belden catalog.)

    Use the "Reply" button to post your digs ;)
     
  19. iLightTheStage

    iLightTheStage Active Member

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    And for when there's a computer but no internet, this program has a dip switch calculator too:
    Paul Pelletier - LD Calculator
     
  20. lieperjp

    lieperjp Well-Known Member

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    Could 3-pin cable be run to a 5-pin connector? (I mean, Pin 4-5 don't do anything anyway...) This is for a wall mounted DMX out box.

    If not, please explain?
     
    Last edited: Feb 11, 2009

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