Wireless DMX issue or Leviton Dimmer Pack Issue?

[techdirector2127]

Good morning,

In my smaller space, I have 3 Leviton D4DMX with 4 conventionals on each of them. From there I use the DMX out to daisy chain 4 LED lights. The manual says that I should be able to daisy chain up to 32 of these dimmer packs together, does this mean that I can only have 36 DMX channels per unit? Every time I try to add anything else to this chain I lose control of the entire electric to the point where I had to forgo I had to daisy chain two of my electrics together to get them to work because the dimmer pack refused to respond to wireless DMX. I also found that channeling everything chronologically helped too. Is there anything anyone sees that I can try to simply make sure that my system works when I need to use it?

 

[DrewE]

32 dimmer packs times four channels per pack is 128 channels maximum in a chain, by my math, for only these dimmers. Moving/LED lights of course consume varying numbers of channels. The limit is the number of physical devices on the DMX bus, not the number of logical channels they respond to (aside from the overall 512 channel maximum of DMX512, of course).

I would guess you may have a cabling or termination issue. Are you using proper DMX cables (and not, say, microphone cables)? Is only the last item in the chain terminated, no more and no less and no others? Are the moving lights and dimmer packs all properly set to DMX operation and not some other mode they may support?

 

[microstar]

The number 32 applies to devices (dimmer packs, LED fixtures, etc.) or stated another way DMX receivers or unit loads in the daisy chain and has no relationship to the number of channels. You could have (theoretically) 32 devices of 16 channels each (512) or 16 devices of 32 channels each (512) for example. Not all receivers count as one unit load; they could be 1/4 of a unit load depending on their circuitry, so you could have even more than 32 devices.

 

[BillConnerFASTC]

I think you could have 32 devices each with 512 channels, if you don't need discreet control of every channel on every device. Just trying to show these are technically separate, though control function usually requires thinking about both.

 

[dbaxter]

Can we please test our understanding to try to better help? Is it the case you have 3 Levitron dimmers and 4 LED lights daisy chained together with the wireless receiver at one end of the chain and a terminator at the other? The dimmer packs are addressed (for example) as 1, 5, and 9 and the LEDs (let's say they are 5 channel instruments) at 13, 18, 23, and 28? That would be as close together as possible. Most folks spread them out a bit.

Edit: Left out 13 at first - sorry I can't count.

 

[microstar]

I think you could have 32 devices each with 512 channels, if you don't need discreet control of every channel on every device. Just trying to show these are technically separate, though control function usually requires thinking about both.

Well of course you are correct. I was unnecessarily limiting myself to only one universe (because that's all I've ever needed to use!)

 

[derekleffew]

(because that's all I've ever needed to use!)

512 oughtta be enuf for anybody!

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...That would be as close together as possible. Most folks spread them out a bit.

I take exception to "most". No functional reason to do so. Good people on both sides.

 

[BillConnerFASTC]

Well of course you are correct. I was unnecessarily limiting myself to only one universe (because that's all I've ever needed to use!)

One universe. You can set every device to start at 1 on first universe. I just wanted the concept of the number of devices is a power limit of DMX drivers (and that may unfortunately open the whole unit, half unit, etc. discussion) and not related to the 512 addresses noted.

 

[dbaxter]

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I take exception to "most". No functional reason to do so. Good people on both sides.

I only do it so that the addresses for colors come out the same for multiple instruments - e.g. 4 LEDs, my reds are at 140,150,160,170; greens at 141,151,161,171; etc. Just easier for me.

 

[FMEng]

There should be two terminators in the system, one at the DMX transmitter, assuming it is at the end of a cable, and there needs to be another terminator at the end of the DMX daisy chain fed by the receiver. In other words, a terminator goes at the end of every physical cable.

 

[Chris Pflieger]

There should be two terminators in the system, one at the DMX transmitter, assuming it is at the end of a cable, and there needs to be another terminator at the end of the DMX daisy chain fed by the receiver. In other words, a terminator goes at the end of every physical cable.

Oh. wait. thinking....

Oh yeah - I've got several "devices" that can transmit and act as a master; those don't have termination like a console.

Looks like I need to make some female terminators.

 

[microstar]

There should be two terminators in the system, one at the DMX transmitter, assuming it is at the end of a cable, and there needs to be another terminator at the end of the DMX daisy chain fed by the receiver. In other words, a terminator goes at the end of every physical cable.

Perhaps I am being confused by the wording above, but according to Adam Bennette's "Recommended Practice for DMX512", the terminator is fitted "at the end of the cable furthest from the transmitter". He also says "... as DMX512 systems are invariably used with the transmitter (i.e. the console) at one end of the line it is only necessary to fit termination at the far end."
He emphasizes with the underlined statement (page 12):
"It is recommended that all DMX512 systems are built with the console at one end of the line ad the terminator at the other end."
There shouldn't be any need for female terminators.

 

[RonHebbard]

Oh. wait. thinking....

Oh yeah - I've got several "devices" that can transmit and act as a master; those don't have termination like a console.

Looks like I need to make some female terminators.

@Chris Pflieger O.K. just as long as you're not making any female impersonators.
Toodleoo!
Ron Hebbard

 

[Chris Pflieger]

Perhaps I am being confused by the wording above, but according to Adam Bennette's "Recommended Practice for DMX512", the terminator is fitted "at the end of the cable furthest from the transmitter". He also says "... as DMX512 systems are invariably used with the transmitter (i.e. the console) at one end of the line it is only necessary to fit termination at the far end."
He emphasizes with the underlined statement (page 12):
"It is recommended that all DMX512 systems are built with the console at one end of the line ad the terminator at the other end."
There shouldn't be any need for female terminators.

If you don't have a console - you have four fixtures, and put one in "master mode", two terminators will be required.

I also use the DFi units from Chauvet DJ. That unit can be set as a xmitter, and a slave in a DMX line, or it can be a receiver and function as a master. I highly doubt there's an EOL resistor that switches on depending on the mode.

 

[FMEng]

Yes, that's tricky language, but let me try to clarify. In my earlier post, I was referring to the wireless, RF transmitter. Mr. Bennette is referring to the circuit driving the cable at the console DMX output as the "transmitter." I think line driver would be better words than transmitter.

The console has a driver and the RF receiver has a driver. A terminator needs to go on every cable daisy chain at the far end from the line drivers. The system, as described, needs two terminations.