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    Robert452
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LED Lighting

Our theatre is running 96 channels to a SENSOR 48 dimmer rack. ALL lamps are incandescent. Snooping around I found a DMX512 outlet "Y" 'd to the dimmer racks line so for my education I bought an inexpensive LED light. I'm well read on DMX512 lines, addressing, protocols etc.

Question; If I program my new LED dimmer's 1st channel address to, say 101, I'll need to send it (and some subsequent addresses) an 8 bit code. On the board it's normal to select a channel and enter a % for an incandescent. So how do I address my LED's code needs? Is it a case of back converting the % figure to 8 bits?  

Parents
  • Are you running Express / Expression? What LED fixture are you using? When you say the LED is 8-bts, do you mean it is an 8-Channel LED?

    Regarding your DMX: please confirm you have a 1-In 5-out opto-splitter? (a box of some kind that is splitting the DMS line)
  • in reply to mmeskill
    Running Expression 3. Using a dirt cheap 'DualFire 18 LED Par Light'. "B bits" refers to the DMX512 data bits sent to the device with the appropriate address (DIM#) on that universe. My cheapo is a 7 channel device (takes up 7 CH on board). Each CH can take a values of 0-255 or a sub range within that. Ref the splitter. Yes - it is a professionally installed splitter.
  • in reply to Robert452
    Yeah, I think he was asking about the splitter because the way you described it made it sound like a splitter cable — something you never want to use in DMX chains.
  • in reply to Aaron Martin
    Oh heavens forbid! I traced my neighbor poor TV reception to a spliced TV cable! His reply to my gasp of horror was "Well, I wanted to run two TV's!" Being deeply into digital comms (W4JPA) I actually had nightmares of his SWR ratio visiting me at night.

    As soon as the theatre quietens down I'm going to sneak in with the LED and try it out. I know the book goes on about "Personalities" but I'm pretty sure for starters I can merely address the 1st and subsequent CH#'s, fire some numbers & to watch the action.
Reply
  • in reply to Aaron Martin
    Oh heavens forbid! I traced my neighbor poor TV reception to a spliced TV cable! His reply to my gasp of horror was "Well, I wanted to run two TV's!" Being deeply into digital comms (W4JPA) I actually had nightmares of his SWR ratio visiting me at night.

    As soon as the theatre quietens down I'm going to sneak in with the LED and try it out. I know the book goes on about "Personalities" but I'm pretty sure for starters I can merely address the 1st and subsequent CH#'s, fire some numbers & to watch the action.
Children
  • in reply to Robert452
    If desired, you could build a fixture personality for it in the offline editor.
  • in reply to Aaron Martin
    Now that's a good idea. I bought a USB 3.5" floppy drive to be able to Tx stuff but the wretched thing didn't work and I sent it back. I'll download that program tonight. Just hung a couple more spots and having my lunch using a back stage amplifier to blast out my music. Being totally alone in a theatre is kinda cool.
  • in reply to Aaron Martin
    Well - I got Freestyler and built a profile for this cheapo LED and had the thing up'n running at home in no time. Great DMX lesson. But alas the trip to the theatre with it was a bust. We have 3 universes leaving the board although we only connect to a single SENSOR 48 Dimmer rack. An outlet on the wall says DMX Port 2 but looks like it's "Y" 'd (Optically isolated) to the 1st universe. But setting dimmers and channels to say 128 and my gizmo to 121 then sending 50% to CH 6 and 7 (which worked fine in Freestyle) didn't do a thing! I would give my eye teeth to know who/how this wiring was run.

    And really weird; On the console, I can set # of dimmers to say 1536 (512 x 3) fine but can ONLY set # of CH's to < 400 ! My idea was to use an address > 512 to see if that outlet really was in the 2nd universe. I thought I was getting pretty good at this stuff but now stalled. Pity because I wanted to buy a couple more LED's for some special effects in "Joseph and the . . . . coat" coming up. Thinking cap time.
  • in reply to Robert452
    Email me your venues name and full address and I’ll see if I can find the wiring diagrams for how the DMX was (at least) originally wired. mmeskill@etcconnect.com
  • in reply to mmeskill
    Based on the submittal / field service drawings (I need to find the ‘as built to confirm):
    3 DMX inputs in the Booth.
    DMX 1 to the Sensor Rack
    DMX 2 to the Stage on a plate with RFU
    DMX 3 to the House
    Based on this, DMX 2 from the board should be wired directly to the DMX 2 output on the stage. Try to remove any external splitter and plug directly to the Output and see if that works.
    Also, I was a little unclear on your addressing. DMX Port 2 from the board would be dimmer 513 in patch; DMX 3 output would be dimmer 1025 in patch; Soooo Dimmer 513 will output from Port 2 as DMX 1. Try patching dimmer 513 to channel 101; 514 to channel 102; 515 to channel 103 and so on for the number of channels your fixtures needs. On the fixture end set your DMX start address to 1.
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