General DMX Questions

[CLD Kevin]

Hello all….I have a few questions about DMX. I’m waiting for the new DMX adapter, but until I see some documentation of it…I guess my questions are directly at the iDMX. Hopefully all applies.



1. Do I need a special DMX splitter if I want to send the signal in different directions? It would be easier to split than to run 1 single cable.

2. Is there a limit to how many devices I can use on 1 single run (up to 512 chs)

3. What distance will the DMX signal travel?

4. Does the DMX signal get regenerated every time it hits a device? I will be using a lot of those little 3Ch DMX modules from RayWu.

5. Does the LOR DMX adapter/controller (new or iDMX) come with the 3 pin adapter for the signal? I think it’s call XLR adapter?

6. The current iDMX has 128 intelligent channels. Does these mean only these 128 will twinkle, shimmer, fade, ect and the remaining is either on/off? Do I need to change any setting for these channels or will it do it automatically?



Thanks

[bisquit476]

Best thing to do is go to Mark's website, download his DMX primer and read it, it'll explain alot.

http://www.woodinvillewonderland.com/howto.htm

[CLD Kevin]

OK. I downloaded and read it…twice. It doesn’t mention anything about the splitter nor the distance. I have a smaller front yard, so I don’t think the distance will be an issue.

It did state that each LOR DMX Network / Universe “Generally allows 32 different fixtures”. I’m using 40 different DMX ch3 modules to feed RGB lights. Will I need 2 DMX Networks even though I’m only using 120 channels (40 modules x 3chs = 120chs)?

[Dr. Jones]

Cracker wrote:

Hello all….I have a few questions about DMX. I’m waiting for the new DMX adapter, but until I see some documentation of it…I guess my questions are directly at the iDMX. Hopefully all applies.



1. Do I need a special DMX splitter if I want to send the signal in different directions? It would be easier to split than to run 1 single cable. yes a splitter would be needed, or you can use wireless.

2. Is there a limit to how many devices I can use on 1 single run (up to 512 chs) per USITT DMX512A standard - 32devices although more can be used based upon the load the chipset puts on the data stream (stick to 32, its safer)

3. What distance will the DMX signal travel? depends on what method of transmission is used. on a single dmx 120ohm cable- 1000feet. Dmx can also be translated into TCP/IP standard, thus greatly increasing the distance. Also DMX can also be sent wirelessly for several hundred yards. there are still many more methods.

4. Does the DMX signal get regenerated every time it hits a device? I will be using a lot of those little 3Ch DMX modules from RayWu. Not all devices re-send the data, most just take a load off of the original signal

5. Does the LOR DMX adapter/controller (new or iDMX) come with the 3 pin adapter for the signal? I think it’s call XLR adapter? the iDMX has a 5pin DMX output

6. The current iDMX has 128 intelligent channels. Does these mean only these 128 will twinkle, shimmer, fade, ect and the remaining is either on/off? Do I need to change any setting for these channels or will it do it automatically? The current iDMX will only fade, shimmer, etc 128 channels at a time. you can fade, shimmer, etc all of the channels, the first 128 that are programmed will be intelligent until their command is complete and will return the ability to be intelligent to the next group



Thanks

hope that helps a little

[Dr. Jones]

Cracker wrote:

OK. I downloaded and read it…twice. It doesn’t mention anything about the splitter nor the distance. I have a smaller front yard, so I don’t think the distance will be an issue.

It did state that each LOR DMX Network / Universe “Generally allows 32 different fixtures”. I’m using 40 different DMX ch3 modules to feed RGB lights. Will I need 2 DMX Networks even though I’m only using 120 channels (40 modules x 3chs = 120chs)?

If you use a powered splitter, you can run all devices on one universe of dmx

[Ken Benedict]

You should be able to handle all of your devices in one DMX loop. If you HAVE to split the signal, use a DMX Distro (splitter) that's made for it. Search Ebay for ENTTEC D-Split. Don't use an audio splitter.

Also, the current iDMX will support a native 512 channels. That's what I'm using to drive the lighting display at the California State Fair. Handles LED PAR 64s, moving mirror DJ units, fog machine, variable speed fog dispersion fan and 3600 watt theatre dimmers. Works perfectly.

The 128 channel limit is for the older firmware, before version 1.41 so just set the iDMX base address to something not on a "10" boundry. See the documentation for the iDMX for details and good luck.

[Dr. Jones]

Ken Benedict wrote:

Also, the current iDMX will support a native 512 channels. That's what I'm using to drive the lighting display at the California State Fair. Handles LED PAR 64s, moving mirror DJ units, fog machine, variable speed fog dispersion fan and 3600 watt theatre dimmers. Works perfectly.

The 128 channel limit is for the older firmware, before version 1.41 so just set the iDMX base address to something not on a "10" boundry. See the documentation for the iDMX for details and good luck.

Ken,

The old limit was 256 channels (16 controllers x16 channels) -this was when running LOR 1.4+. This changed to all 512 with S2. The 128 limit is the current amount of intelligent channels or Ichans. An intelligent channel has the ability to do specialized commands i.e fade shimmer, etc. For example - if you tried crossfading 256 channels at the same time, the first 128 will fade in the allotted time where as the remaining 128 will jump to the new level.

Dan - please correct me if I am wrong, but I don't believe LOR has increased the Ichans on the iDMX.

[CLD Kevin]

Thanks Dr Jones and Ken for the helpful answers.

As for the splitter, I will get the ENTTEC. I only need it to split 2 ways. It sounds like I can run all 40 RGB devices in one universe so that is good news.

Also for question #5, per LOR docs it’s shows it as a XLR3…3 pin adapter and not 5. http://www.lightorama.com/PDF/iDMX-1000.pdf



I’m guessing the iDMX doesn’t come with an XLR3 female adapter. Because my DMX 3ch modules for the RGB lights are just open wires...can I purchase a standard XLR3 cable, cut one end off and connect the wires to a cable to extend to my devices? Or is there already a cable that has XLR3 on one end and open on the other?

I found these on ebay...would they work? http://cgi.ebay.com/4pcs-XLR-3ways-Female-Straight-Cable-Plug-Connecor-/200624114197?pt=LH_DefaultDomain_0&hash=item2eb6210a15


Let me try to explain what I would like to do. Use an 18awg 4-wire cable as my "Main DMX" cable and run next to all DMX Ch3 modules (I have 1000ft of this cable so I would like to use it if possible). I want to inject power onto the same cable so 2 wires for the 12v power and 2 wires for the DMX signal. Then 'T' off the power and DMX signal to each device from the "Main DMX" cable. I know there is also a ground wire on the iDMX, but do I really need this ground for my application? I will only be using these small DMX 3ch modules...for RGB lights and Rainbow Floods. No crazy, bandwidth hog, moving DMX devices.

Kevin

[Dr. Jones]

Cracker wrote:

Thanks Dr Jones and Ken for the helpful answers.

As for the splitter, I will get the ENTTEC. I only need it to split 2 ways. It sounds like I can run all 40 RGB devices in one universe so that is good news.

Also for question #5, per LOR docs it’s shows it as a XLR3…3 pin adapter and not 5. http://www.lightorama.com/PDF/iDMX-1000.pdf

Kevin - you are correct, I checked my spare and iot is 3pin (I have modified all of mine to 5pin)


I’m guessing the iDMX doesn’t come with an XLR3 female adapter. Because my DMX 3ch modules for the RGB lights are just open wires...can I purchase a standard XLR3 cable, cut one end off and connect the wires to a cable to extend to my devices? Or is there already a cable that has XLR3 on one end and open on the other?

Yes you sure can - as long as it is DMX cable and not audio cable

I found these on ebay...would they work? http://cgi.ebay.com/4pcs-XLR-3ways-Female-Straight-Cable-Plug-Connecor-/200624114197?pt=LH_DefaultDomain_0&hash=item2eb6210a15

Sure - I personally prefer Neutrik connectors (NC3FX and NC3MX)


Let me try to explain what I would like to do. Use an 18awg 4-wire cable as my "Main DMX" cable and run next to all DMX Ch3 modules (I have 1000ft of this cable so I would like to use it if possible). I want to inject power onto the same cable so 2 wires for the 12v power and 2 wires for the DMX signal. Then 'T' off the power and DMX signal to each device from the "Main DMX" cable. I know there is also a ground wire on the iDMX, but do I really need this ground for my application? I will only be using these small DMX 3ch modules...for RGB lights and Rainbow Floods. No crazy, bandwidth hog, moving DMX devices.

Please dont -you are about to open up a can, DMX should always be run on 120ohm cable. You can use a an xlr connector and wire to run both data and power. Professionally - scroller cable sends data and power down the same wire and uses a 4pin connector (the shield/ground/drain is connected to the connector body) Otherwise 6 and 7 pin or RJ45 connectors can be used

edit- clarification

[CLD Kevin]

Dr. Jones wrote:

Cracker wrote:

Let me try to explain what I would like to do. Use an 18awg 4-wire cable as my "Main DMX" cable and run next to all DMX Ch3 modules (I have 1000ft of this cable so I would like to use it if possible). I want to inject power onto the same cable so 2 wires for the 12v power and 2 wires for the DMX signal. Then 'T' off the power and DMX signal to each device from the "Main DMX" cable. I know there is also a ground wire on the iDMX, but do I really need this ground for my application? I will only be using these small DMX 3ch modules...for RGB lights and Rainbow Floods. No crazy, bandwidth hog, moving DMX devices.

Please dont -you are about to open up a can, DMX should always be run on 120ohm cable. You can use a an xlr connector and wire to run both data and power. Professionally - scroller cable sends data and power down the same wire and uses a 4pin connector (the shield/ground/drain is connected to the connector body) Otherwise 6 and 7 pin or RJ45 connectors can be used

edit- clarification

I guess I need to go a different route with my DMX cabling. I want to keep both power and the DMX signal on the same cable. Just need to figure out which cable would best fix my needs.

[zman]

Cracker, all the answers are here. But I will hope to clear up some things:

1. Generally 32 devices. RS485 has a 32 unique device limit. Some of the newer drivers will support more devices. You can slave a ton if you have the power. Meaning, more than one device has the same Base Address.
1.a If you have a powered splitter, each "branch" can have 32 unique devices.

2. Your DMX cables are for comms only. Power is separate. There are products, (LOR and others) that use PLC. This is designed to be used this way within the LOR environment. DMX512A only allows for RDM within the protocol, no power that I am aware of.
2a. If you are using RGB modules, and running 5v/12V, then yes, power is run in that ribbon cable. Look at David Moores Holiday Coro.com site. He has a great 4 part RGB video series that will explain these devices, the power and comms requirement. It is worth the hour to watch the videos.

3. Ichans (Intelligent channels) are unique to DMX LOR. I have no idea what they will do for S3 when they go to native DMX. These channels are a use as needed. Meaning 128 channels can be dimming, twinkling, shimmering at a time. Once the effect if finished, it is freed up. If more than that get the call, I have no idea what will happen, but it most likely won't be pretty. At your RGB count above keeps you under the limit. The big issue I see is when channels fade at the end of a sequence with the music. There are cheaper solutions for a Splitter than commercial. Look at the DIY, DIYLA, or Aussie Christmas site for a do it yourself version that will be a LOT less. Any other DMX channel that is on or off, or set at a value does not require an Ichan, so they run at the same time.

4. The iDMX is a 3 pin XLR. 5. Cabling is like religion. It is what you believe, and how you act. You can use DMX cables as Dr. Jones pointed out which are designed (and shielded) for DMX signals. Some use Mic cable, not optimum, but works. A LOT use just CAT5. Again it is acceptable as part of the ESTA DMX512A, but you have to worry about power noise. I would not run that near any power cables.

5. Each branch can be up to 4000', again if powered. A terminator would be required on the end of each branch.

[CLD Kevin]

zman wrote:

Cracker, all the answers are here. But I will hope to clear up some things:

1. Generally 32 devices. RS485 has a 32 unique device limit. Some of the newer drivers will support more devices. You can slave a ton if you have the power. Meaning, more than one device has the same Base Address.
1.a If you have a powered splitter, each "branch" can have 32 unique devices.

2. Your DMX cables are for comms only. Power is separate. There are products, (LOR and others) that use PLC. This is designed to be used this way within the LOR environment. DMX512A only allows for RDM within the protocol, no power that I am aware of.
2a. If you are using RGB modules, and running 5v/12V, then yes, power is run in that ribbon cable. Look at David Moores Holiday Coro.com site. He has a great 4 part RGB video series that will explain these devices, the power and comms requirement. It is worth the hour to watch the videos.

3. Ichans (Intelligent channels) are unique to DMX LOR. I have no idea what they will do for S3 when they go to native DMX. These channels are a use as needed. Meaning 128 channels can be dimming, twinkling, shimmering at a time. Once the effect if finished, it is freed up. If more than that get the call, I have no idea what will happen, but it most likely won't be pretty. At your RGB count above keeps you under the limit. The big issue I see is when channels fade at the end of a sequence with the music. There are cheaper solutions for a Splitter than commercial. Look at the DIY, DIYLA, or Aussie Christmas site for a do it yourself version that will be a LOT less. Any other DMX channel that is on or off, or set at a value does not require an Ichan, so they run at the same time.

4. The iDMX is a 3 pin XLR. 5. Cabling is like religion. It is what you believe, and how you act. You can use DMX cables as Dr. Jones pointed out which are designed (and shielded) for DMX signals. Some use Mic cable, not optimum, but works. A LOT use just CAT5. Again it is acceptable as part of the ESTA DMX512A, but you have to worry about power noise. I would not run that near any power cables.

5. Each branch can be up to 4000', again if powered. A terminator would be required on the end of each branch.

Thanks all for the clarification. Its good to know that if I use a power DMX splitter, that I can get 32 unique devices per "branch". My 40 devices should work on one universe as long as I use a power splitter. I check out the DIY splitter and looks like a nice unit. I’ll have to contact RJ for the board.

I have watch David's videos before…several times. I guess I misunderstood the wiring cable requirements for DMX. It didn't really state it in his videos, but after more research...as you stated, a lot use CAT5. Maybe not the best method, but does work. My bad for not clearly understanding this because I just started buying material which not will not work.

I'm using the same DMX 3ch modules and RGB modules as David used for his CoroStars...although I’m using for other props. He was able to inject power and send the DMX signal on the same CAT5 cable for up to 10 stars, but not to exceed 20ft between each star per his instructions.

http://www.holidaycoro.com/docs/CoroStar%20Assembly%20Instructions.pdf

This will work for my requirements although I would like to have some type of plug at each connection so it would be easy to put together, replace bad modules and take apart for storage...but that’s me just being meticulous.

David used one pair for the DMX signal and the other 3 pairs for power. You stated not to mix the DMX signal and power cable together or near. Is the power you referring to 120VAC power? Is 12VDC acceptable...or should I say will work?



Kevin

[zman]

Kevin, with 12VDC you will not have to much to worry about in terms of interference. Yes, it is the 120V that causes problems.

Look at David's RGB Ball instructions. In that he discusses using CAT5 and CAT5 splitters. Something like that may give you the modularity it sounds like you are looking for.

[CLD Kevin]

I have a couple more questions to add...



1. Do I still need a DMX terminator if my line (Universe) ends at a fixture or in my case...3CH DMX Module? Or only use a terminator if the line is open at the end? Info on DMX terminator:
http://www.thedmxwiki.com/definitions/dmx_terminator



2. I used DMoore instructions for his RGB Ball. I’m using Cat5 cable to control and power RGB modules. The DMX signal is on 1 & 2 and the power & ground on the rest. If I’m using the iDMX for the controller, do I need to use this XLR to RJ45 adapter from here: http://www.productionadvantageonline.com/Control-Adapters-Terminators/XLRJ45-3M.aspx

Or the one sold from LOR? This was discussed on another post http://forums.lightorama.com/forum75/27496.html but the Rainbow Brian was used for the controller.



Kevin

[Steven]

Cracker wrote:

1. Do I still need a DMX terminator if my line (Universe) ends at a fixture or in my case...3CH DMX Module? Or only use a terminator if the line is open at the end?

Yes, you need a DMX terminator. It's possible that a DMX fixture may include a optional built-in terminator, but I would think that would only be the case if the fixture had only a single DMX socket or a clearly-labeled switch. Why would you have a line that is open at the end anyway?

2. ... do I need to use this XLR to RJ45 adapter from here: http://www.productionadvantageonline.com/Control-Adapters-Terminators/XLRJ45-3M.aspx

Yes. That's the one you need.

Or the one sold from LOR? This was discussed on another post http://forums.lightorama.com/forum75/27496.html

No. As I mentioned in that thread, the LOR XLR-to-RJ45 adapter is only used to connect a LOR controller to a DMX universe. Few of us will do that because we are mostly using LOR software and it makes much more sense to put the LOR controller on the LOR network.