# DMX splitting

#### DavidJones

##### Well-Known Member
Janell's stuff is great.
From Chauvet Pro, we have the RDM Splitter 8, which can act as a 2x4 or 1x8 splitter for DMX and RDM. street price is about $429. Unless you know you need a bunch of splits of the same universe, I'd go with one or two NET-X II. I feel the days of running DMX cable over long distances are over. For the price of running one universe over DMX, you can pull a CAT6 a have thousands of universes. Cat6 probably costs less per foot than DMX now as well. Switch in the booth, or maybe the dimmer room. Cat 6 to a bunch of locations, drop a Net-X In in/near the foh positions, and another on/above the stage, and distribute from there. The Net-x are great sACN nodes, and splitters. The only downside would be not being able to configure them from the console like you can with ETC nodes. But that is the same with any console once you leave the manufactures specific product line. The Net-X does have a decent web interface where you can configure and name outputs and load settings, etc. What I don't like about the ETC NET3 nodes, is the inability to configure the outputs locally from the node, you have to use a desk or computer. On the Net-x you can configure it from the front panel. #### BillConnerFASTC ##### Well-Known Member Unless you know you need a bunch of splits of the same universe, I'd go with one or two NET-X II. I feel the days of running DMX cable over long distances are over. For the price of running one universe over DMX, you can pull a CAT6 a have thousands of universes. Cat6 probably costs less per foot than DMX now as well. Switch in the booth, or maybe the dimmer room. Cat 6 to a bunch of locations, drop a Net-X In in/near the foh positions, and another on/above the stage, and distribute from there. The Net-x are great sACN nodes, and splitters. The only downside would be not being able to configure them from the console like you can with ETC nodes. But that is the same with any console once you leave the manufactures specific product line. The Net-X does have a decent web interface where you can configure and name outputs and load settings, etc. What I don't like about the ETC NET3 nodes, is the inability to configure the outputs locally from the node, you have to use a desk or computer. On the Net-x you can configure it from the front panel. I believe ETCs new Mk2 series is fully configurable at the node, as well as on console. #### Massey28694 ##### Active Member We have a lot of splitting options! Our 124 splitter has 4 outputs, and is DMX/RDM compatible. MSRP is$433, and all of our products come with a 5 year warranty. Additionally, if you're looking at having long runs of cable where you're worried about the validity of the signal, you can plonk a DMXDECELERATOR in the middle of the run. (MSRP $210) It receives, re-times, and re-broadcasts the signal, and boosts the signal for your longer cable runs. It's also a handy thing to have just in case some of the fixtures your building chooses down the line (with budget constraints) don't play nice with DMX timing requirements. Thanks @jflleenor... just for my education, what would you consider to be a "long" cable run? Thanks again for your thoughts! #### Jay Ashworth ##### Well-Known Member It's good you put in a pullstring. It is twice the length of the pull, right? (If not, use it to pull in another one that is, and then recycle it.) #### BillConnerFASTC ##### Well-Known Member Massey - I believe 1000 feet is usual good practice - that's device to device including patch cords if any. Technically I think you can go further. A splitter restarts the 1000'. #### Massey28694 ##### Active Member Have spent the afternoon researching gateways, spitters, and the such, and my head is spinning! A few questions: we would like to be able to use RDM on our new Element 2. ETC manual says in order to use RDM, the console must be attached to a Net3 or Response gateway. I'm planning multiple "splits", so does this mean only the FIRST split would have to be an ETC gateway or all my splits? I hear loud and clear the benefits of using the best equipment I can afford and I am very much with the idea of longterm stability in our little system. But keeping in mind we have a small system, dmx cabling of maybe 360' including future potential patch cables. I do not want my lights going out in the middle of a show, but can I get away with maybe my first split being the ETC gateway (if required), and then 3 other dmx distributors (or I guess dmx/rdm distributors) leading to the other main lighting locations? Does anyone have realtime experience with Enttec splitters? What what I see online, they are pretty decent and offer a nice alternative for those of us without a Lexus budget. Changing gears just a bit, I know it would be best to have relays to control my 120v power to devices. I am totally nuts to think I can use dmx controlled power modules (not ETC relays, as much as I would like to have them) to control actual device power, or even these wifi power switches, like Wemo. ?? Brain is smoking, time for a break! Appreciate you all more than you know! Thanks guys. #### BillConnerFASTC ##### Well-Known Member There are plenty of dmx controlled relays. ETCs foundry mini panel is under$800 for 8 circuits. If you can do without dmx control, at least til you build an interface, there are lots of relay panels.

The only reason imho to use the ColorSource relay is the wireless DMX distro that comes with. Plug and play.

#### SteveB

##### Well-Known Member
For relays, just pay attention to the need for a real “air-gap” style relay that mechanically opens the circuit. The Color Source relay is one such item. Some so-called “relays” are only a solid state device that sets the switch into a so-called “non-dim” mode, allowing full voltage under most conditions, but is not a real mechanical style switch. The solid state models are often similar to SCR dimmers set into full on state. It’s not the same.

As to RDM. I have mixed feelings and experiences with it. To make good use, all your splitters need to be RDM capable. Then you would want all the fixtures to be RDM as well. On my system which has a lot of ETC LED gear as well as some Elation movers, the Elation are not RDM compliant. Thus I have to pay attention to which nodes are sending DMX to Elation gear and shut off RDM. Else the gear can exhibit all kinds of weird behavior. Thus I tend to just not use RDM at all and just find other ways to get addressing to the fixtures.

#### jfleenor

##### Well-Known Member
Thanks @jflleenor... just for my education, what would you consider to be a "long" cable run? Thanks again for your thoughts!
As has been mentioned, 1000' is considered the longest length of a single continuous stretch of cable you'd want to run before worrying about the niceness of the signal. There are a couple pages on our website, looked in my signature, that can explain it a bit better.

Happy Sunday night!

#### Massey28694

##### Active Member
For relays, just pay attention to the need for a real “air-gap” style relay that mechanically opens the circuit. The Color Source relay is one such item. Some so-called “relays” are only a solid state device that sets the switch into a so-called “non-dim” mode, allowing full voltage under most conditions, but is not a real mechanical style switch. The solid state models are often similar to SCR dimmers set into full on state. It’s not the same.

As to RDM. I have mixed feelings and experiences with it. To make good use, all your splitters need to be RDM capable. Then you would want all the fixtures to be RDM as well. On my system which has a lot of ETC LED gear as well as some Elation movers, the Elation are not RDM compliant. Thus I have to pay attention to which nodes are sending DMX to Elation gear and shut off RDM. Else the gear can exhibit all kinds of weird behavior. Thus I tend to just not use RDM at all and just find other ways to get addressing to the fixtures.
Sounds like RDM could be a problem. After learning more about it, I have been looking at dmx/rdm splitters. But do I understand correctly that if an instrument is NOT RDM, I may need a separate comm line to talk to the non-RDM instruments, otherwise I may be in for some surprising behavior? Sounds like I should maybe forget RDM for the moment. What capabilities do I lose by not having RDM?

#### SteveB

##### Well-Known Member
Without RDM, for RDM compliant fixtures, you loose the ability to set address and various modes from the ground. Yes, you may have to turn off RDM for a show if using non-compliant fixtures, but you need it for set up.

Try https://www.learnstagelighting.com/what-is-rdm-and-why-does-it-matter-to-me/ for more.
I wouldn't phrase it as soundling likes its essential. It isn't. More like very useful at times.

Here's what we experienced in load-ins of medium size rigs with 150-200 LED's and ML's. The practical application is I would hang and power all (or parts) of my system a well as connect up via DMX distribution (ETC Gateways in my case) all the equipment that needs DMX.

If I am using RDM I might not need to pre-configure the DMX address for any of the gear. That can save a chunk of time as when you pre-set addresses, you have to have local power and the requisite paperwork as to what the Address needs to be and where the fixture is to hang in the plot. We accomplish this by using Lightwright to pre-assign addressing to fixtures, then print labels to stick on the fixture (usually a Lustr or D60 yoke) that have the address as well as channels, position and unit number, so this part isn't too onerous IF you can get at the gear prior to hang, or at least can access prior to flying the rig.

If every fixture is RDM compliant (the ETC gear is) I could view that entire rig of equipment on screen on my Ion console. The console does NOT tell me where each and every unit is located but does provide the ability to "flash" intensity for fixtures. Thus and assuming the fixture is in sight of the console, you can see the fixtures and then patch to the appropriate console channel (using ETC speak). If you cannot see the fixture, you might need somebody on radio who can observe the fixtures, possibly with the plot to verify the fixture and call back the channel number (or however you choose to do this) so you can patch it (as far as I can determine, you cannot view the RDM info in any app on a tablet, or on a RRFU. You could potentially use a laptop in Client mode and try that, I haven't tried this).

In this (very particular) scenario we have not found RDM to be that helpful as it requires at least 2 (console conversant) crew to work IN THE THEATRE, during the load-in process. We find it easier to pre-address and label and then dump the Lightwright patch direct to console as an import. And as well I still have to go back to verify that whatever Gateways might be sending DMX to devices to set that gateway to RDM Off so as not not induce flicker on non-compliat fixtures. . That then loses some of the functionality RDM provides for any compatible fixtures getting DMX on that gateway.

YMMV

#### BillConnerFASTC

##### Well-Known Member
And as well I still have to go back to verify that whatever Gateways might be sending DMX to devices to set that gateway to RDM Off so as not not induce flicker on non-compliant fixtures. . That then loses some of the functionality RDM provides for any compatible fixtures getting DMX on that gateway.
But for set up, you can still use the RDM for those fixtures that are compliant on that gateway, correct? You only have to turn it off for the event. And RDM is of minimal value during the event, correct?

It also sounds like you strip and rehang for every show. If fixtures stay in the air and are maybe or maybe not repurposed for different events, would it be more useful? And I guess you could leave fixtures "permanently" addressed but it does seem some lose their settings from time to time.

If you have architectural lights on DMX, its really nice to be able to address from afar, since they are spread around and don't have as friendly of user interfaces usually.

Massey28694

#### SteveB

##### Well-Known Member
But for set up, you can still use the RDM for those fixtures that are compliant on that gateway, correct? You only have to turn it off for the event. And RDM is of minimal value during the event, correct?

It also sounds like you strip and rehang for every show. If fixtures stay in the air and are maybe or maybe not repurposed for different events, would it be more useful? And I guess you could leave fixtures "permanently" addressed but it does seem some lose their settings from time to time.

If you have architectural lights on DMX, its really nice to be able to address from afar, since they are spread around and don't have as friendly of user interfaces usually.
As noted, using RDM when you cannot see a whole lot of the rig to Flash On, means a somewhat slower process to get it patched. Plus a 2nd crew to call out info. In some respects its easier to pre-assign, then set addresses on the rig once powered, as you can have multiple people doing this, IF THEY PAY ATTENTION !. But this is the rub, that electricians these days need to have this skill set, so we make use of it when we can. And the with a patch done on a data import, it’s really then just a channel check.

We finally, finally are leaving a catwalk and box boom rep plot in place. The addressing and power assignments for these don’t change, this I’ve no need to deal with these units, RDM ready or not.

I somewhat hope others will contribute to this discussion as to how they HAVE found RDM useful. I’d like to learn some tricks as well.