# DMX over Ethernet



## Shawncfer (Jul 19, 2010)

Okay.. So I just got hired at this brand new high school to hang and focus a basic lighting plot for them for the new school year. Btw, lt me start by venting here. This school has an Eos in the mainstage and an Ion in the black box. 250 dimmers in the mainstage, 50 on the FOH catwalk, and two side ...... dont know the term for it but like rooms on the side walls to hang lights from. 6 High end moving lights (not exactly sure what kind) and all their rigging is motorized. Oh, and a Hydraulic Orchestra Pit.  Man, I wish I went to that high school :neutral:

Anyways. So I've always heard of DMX over Etheret but I've never seen it in action. Until now. It turns out this school runs Dmx over Ethernet. So I need some help here; I have a couple questions.

First, if theres one Ethernet output from the board, then how are there so many outputs everywhere? I mean, I see all these outputs saying "Lighting Network" with an Ethernet output which runs to this little box and then has a DMX output. So how do they get the Ethernet to run to all those places?

Second, how do you address the fixtures? I mean, on moving lights I've worked with, that address only goes from 1-512. But what if I want more than that? I know that with DMX512 I would address it as 1 and then if it came out of the second Universe it's address would be 513... So this throws me off a little bit. 

Oh, and theres something called SmartSwitch by etc... the hell is that? 

Here are a couple pictures I took. I don't know if they're of anything having to do with this, but mabe you can help


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## ajb (Jul 19, 2010)

> First, if theres one Ethernet output from the board, then how are there so many outputs everywhere?


 You use an ethernet switch, which is the bluish device in your second picture with all of the cat5 cables plugged into it. The black panel below it that all of those cables go to is a patch panel, where the fixed building wiring meets the flexible device wiring. An ethernet hub is to ethernet what an optosplitter is for DMX, except bidirectional. Any data that comes into any one port gets repeated on all of the other ports. Hubs are not often used these days, since they just blast data every which way, so usually switches are used instead. A switch is smarter than a hub, in that when it receives traffic on one port, it knows which port(s) are connected to device(s) that should receive that traffic, and repeats the traffic only on that port(s).


> Second, how do you address the fixtures? I mean, on moving lights I've worked with, that address only goes from 1-512. But what if I want more than that? I know that with DMX512 I would address it as 1 and then if it came out of the second Universe it's address would be 513... So this throws me off a little bit.



If you're using a native DMX device, you address it to somewhere in that 1-512 range, and then plug it into some sort of ethernet-DMX bridge. That bridge device will be addressed so that the console can talk to it on the network, and can be configured to translate, say console addresses 513-1024, or 1025-1536, into DMX addresses 1-512 and send that data along to whatever DMX devices are connected to it. In this way, any number of DMX-ethernet nodes can translate any range of console addresses to a 'standard' range of 512 DMX addresses. Simple arithmetic will tell you that if you want to talk to a device that is at DMX address 13 on the node that is handling console addresses 1025-1536, you would need to use channel 1024+13 = 1037 on the console. Multiple nodes can also be set to handle the same console address range if you want to keep things simpler.


> Oh, and theres something called SmartSwitch by etc... the hell is that?



http://www.etcconnect.com/product.overview.aspx?ID=20056

Essentially DMX (or SmartLink, or. . .) controlled non-dim circuits, for things that you want to turn on and off but do not want to dim.


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## Les (Jul 19, 2010)

Shawncfer said:


> and two side ...... dont know the term for it but like rooms on the side walls to hang lights from.



I hear them called box booms or just 'booms' more often or not. Occasionally, someone will call them 'boxes' and I've also heard them referred to as alcoves, or coves for short. I call them alcoves personally, because it sounds nice and it's easy to say.

Schools like these are nice to work in, but you have to wonder, what do the students do when they have to work in a real-world venue with 1/4 the inventory and technology that is 20 years past its prime? They freeze up, that's what they do.

Tax dollars hard at work!


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## Shawncfer (Jul 19, 2010)

Les said:


> Schools like these are nice to work in, but you have to wonder, what do the students do when they have to work in a real-world venue with 1/4 the inventory and technology that is 20 years past its prime? They freeze up, that's what they do.
> 
> Tax dollars hard at work!



I Completely agree! I think it's important for kids to learn to work with all this technology and learn how to use all this new stuff. But at the same time I think it's important for kids to learn older equipment as well. I mean, something as basic as a counter balance fly system. I mean, it's not that hard to learn to use, but what will kids to if they go to a college or work in the industry professionaly and someone asks them to fly something up? They won't know what to do!


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## Shawncfer (Jul 19, 2010)

ajb said:


> If you're using a native DMX device, you address it to somewhere in that 1-512 range, and then plug it into some sort of ethernet-DMX bridge. That bridge device will be addressed so that the console can talk to it on the network, and can be configured to translate, say console addresses 513-1024, or 1025-1536, into DMX addresses 1-512 and send that data along to whatever DMX devices are connected to it. In this way, any number of DMX-ethernet nodes can translate any range of console addresses to a 'standard' range of 512 DMX addresses. Simple arithmetic will tell you that if you want to talk to a device that is at DMX address 13 on the node that is handling console addresses 1025-1536, you would need to use channel 1024+13 = 1037 on the console. Multiple nodes can also be set to handle the same console address range if you want to keep things simpler.


 
Oh okay. So I can change a node if I want to be whatever range I desire correct?

Now another thing. Theres a couple places with the ethernet out like in that one picture but its not hooked up to a node. And they gave us a couple extra nodes. So Im sure we could put them where the ethernet out is if we want. But I noticed the extra nodes came with a cd that says instalation cd.. Do I have to hook it up to a computer or something? or do I just plug it in and go?

And as far as the smartswitch, I though that was what the R20 modules were for??? On and off but no dim. Why do you need the smart switch?


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## Les (Jul 19, 2010)

Shawncfer said:


> I Completely agree! I think it's important for kids to learn to work with all this technology and learn how to use all this new stuff. But at the same time I think it's important for kids to learn older equipment as well. I mean, something as basic as a counter balance fly system. I mean, it's not that hard to learn to use, but what will kids to if they go to a college or work in the industry professionaly and someone asks them to fly something up? They won't know what to do!



You have a valid point. Back when I was in high school, we had a fresh renovation (completed half way through my Freshman year) with motorized battens. It was great not having to worry about adding and removing weights whenever we'd do a new hang, but the kids at the cross town rival school were way ahead of us in educational regards because they had a counterweight system. Their school was relatively new, having been built in the '90's. Our technology and overall space was better, but they learned more rigging fundamentals than we did. Sure, there's always college, but some people don't go to college and instead choose to go straight in to the field. In their case, it would be nice to have learned the basics in high school rather than out on the job where time is money.

Hydraulic orchestra pits are nice, but are they necessary in a high school where it will only get used a couple times a year?


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## Lightingguy32 (Jul 19, 2010)

FYI, the ethernet switch you have is cisco, you may want to look into having all of your dedicated lighting network ports programmed such that they only give/accept connection(s) to the lighting equipment and not to computers if someone comes by and unplugs one of the ports. Where is the switch located, as they age, the fans get a little loud(er) and if it's back stage on a wall, it won't be any fun because almost anyone will hear it


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## millamber (Jul 19, 2010)

Shawncfer said:


> Oh okay. So I can change a node if I want to be whatever range I desire correct?



Correct. From the photo, you are using a Net3 network, so do do this you would use Gateway Configuration Editor (see below)


> Now another thing. Theres a couple places with the ethernet out like in that one picture but its not hooked up to a node. And they gave us a couple extra nodes. So Im sure we could put them where the ethernet out is if we want. But I noticed the extra nodes came with a cd that says instalation cd.. Do I have to hook it up to a computer or something? or do I just plug it in and go?



If your factory turn on person setup your gateways(nodes) when the system was commisioned then you may be able to plug and play. If not, or if you want to change the start address of the gateway, you'll have to use Gateway Configuration Editor or GCE. The CD that comes with the extra gateways should have it on there, or the latest version is available from ETC's website. By using a computer on the network, you will be able to see all the gateways in use in the system and be able to set their start addresses as well as several other things.


> And as far as the smartswitch, I though that was what the R20 modules were for??? On and off but no dim. Why do you need the smart switch?



The Smartswitch is there to give you a large number of relays controllable by dmx. Yes, an R20 will do a similar job, but it is only 2 circuits per module, and you'd have to sacrifice a slot in your Sensor rack. The smartswitch allows for up to 48 relays per panel. Not to mention that it is less expensive than the equivalent number of R20 modules.


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## Shawncfer (Jul 19, 2010)

millamber said:


> If not, or if you want to change the start address of the gateway, you'll have to use Gateway Configuration Editor or GCE. The CD that comes with the extra gateways should have it on there, or the latest version is available from ETC's website. By using a computer on the network, you will be able to see all the gateways in use in the system and be able to set their start addresses as well as several other things.


 
Okay, so I just get a regular computer, pop in the cd, and I plug it into the system and I can change the start addresses, names, and other stuff like that? Where do I plug my computer into?


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## starksk (Jul 19, 2010)

Shawncfer said:


> Okay, so I just get a regular computer, pop in the cd, and I plug it into the system and I can change the start addresses, names, and other stuff like that? Where do I plug my computer into?


 
You only need the CD to install GCE. After that, it will run from your hard drive.

You can connect your computer to any one of the Ethernet ports labeled Lighting Network. You will need to configure your computer to be in the correct IP scheme to match your lighting network and be able to communicate with the devices online.

The ETC standard IP scheme is a 10.101.x.x network, but it is possible that your system is configured differently.

I recommend that you start by setting your computer to have a static IP address of 10.101.1.101. You will also need to set the subnet mask to 255.255.0.0 and your computer's default gateway to 10.101.1.1. 

Once you are connected and online, you will be able to see your network devices in GCE and be able to configure them as you need.


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## Shawncfer (Jul 19, 2010)

starksk said:


> You only need the CD to install GCE. After that, it will run from your hard drive.
> 
> You can connect your computer to any one of the Ethernet ports labeled Lighting Network. You will need to configure your computer to be in the correct IP scheme to match your lighting network and be able to communicate with the devices online.
> 
> ...



Is this something you need a pc for or is mac okay?


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## starksk (Jul 19, 2010)

Shawncfer said:


> Is this something you need a pc for or is mac okay?


 
GCE is a PC based application.


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## ship (Jul 19, 2010)

On the other hand, it’s possible to use Cat.5E cable for DMX cable. This especially in an architectural setting for the wiring. The twists in the wire cancels out the need for shielding - though I wouldn’t say loom a Cat.5E cable into a feeder cable line. Been known to work for a few years now. Simply use this cable instead of DMX cable. Not as rugged - the off the shelf Cat.5E cable, but suitable if in an installation.

Other Cat.5E types of production cable with heavy duty jackets are on the market on the other hand such as used with many RJ-45 type devices for feeding data inside racks or to some newer types of lights. Such cable can also be used for DMX - though the extra not-used conductors be sure to not just cut back, but heat shrink cap off or any play in the cable could cause shorting between pins the same as extra conductors in a DMX/XLR cable can cause gremlens in a system when not used and get to float about inside of a plug. 

Of these above Cat.5E production cables, a caution... some brands of cable don’t get along with Grand MA consoles. Just had to scrap like 2,000' of a cheaper brand because they don’t work properly. Work fine on most other consoles... just something about the Grand MA. that these cables don’t work well with.

Didn’t find the link but TMB has recently done some research into the use of their Cat.5 ProCable version with the use of it for data and Clear Com. Very expensive cable and adaptors to do it, but gotta say that it does work. Currently play testing like a 100' siamese Cat.5 data snake - the second on cable on the line is a spare so far. The fan-outs for data work without problems so far. And testing their multi-pair Cat.5 with our 37pin Socapex multi-pin standard for six channels of true DMX and two channels for Clear Com. Despise the 37pin Socapex plug, but given hundreds of them in use, I’m stuck with using them. The multi-pair Cat.5 snake has been in use for a few months now and been on a few shows without a problem. Pinology I had to figure out for myself but it works in using three Cat.5 pairs for data and the fourth for Clear Com. 

TMB does have a PDF for pinology on their products and it’s useful and interesting. Did a short search for it on their web page but didn’t find it. One should follow or at least base off of it if doing Cat.5 cable for DMX. The above four pair Cat.5 snake with my Soco ends is 400' long. Works without a problem so far. Clear Com and DMX are different than Cat.5 with a 300' limit. 

Still play testing both but so far it seems like I’ll be switching out to this concept with time over more normal - in my case, 8 to 16 pair digital grade multi-pair snakes made for the sound industry for use as DMX snakes. They work but also don’t last as long with wear and tear. Tend to hog tail themselves also when loomed with a 8/5 SO cable for instance. The “Bullet Proof” Pro-Cable lines of cable are expensive but often really good. TBA how “good” the four pair Cat.5 snake or Siamese cable with very expensive fan-in and fan-out will be for cost effectiveness. Lasts a few years without having to fix, paid for themselves in cost. Anyway, what I’m currently play testing and germain to the subject I think.

Sub note, on the 300' spools of sub-grade production quality Cat.5 cable which don't work with Grand MA consoles... much of it was recycled, some given away and I took a length of it for use at home on the work lap top. Got this wireless tunnel to my work computer and in connectiong to it a bad wireless connection to the upstairs wireless network - between cement floors and metal doors on a lower floor, in signal strength between the upper story network and my "office" or Man-Zone as it were It frequently knocks me off the internet given weather conditions or what ever and I cannot connect to the tunnel at all. Concept is I'll run the Cat.5 to this computer so I can access what I need to from my work compuer again and or have a strong wired plugged in signal for the net. (This post was already lost once in posting...) Ah' a good hard line connection.. just gotta crawl up into the ceiling and feed it in something I'm not looking forward to.


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## Shawncfer (Jul 19, 2010)

ship said:


> On the other hand, it’s possible to use Cat.5E cable for DMX cable.


 
What the!!! Cat.5E???

What is that?!? I mean, I look at is as ethernet cable, not Cat.5E or Cat 3... someone help me out!


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## ship (Jul 20, 2010)

Replace for your purposes Cat.5, Cat.5E or Cat.6 cable designations for your Ethernet description. Less technical but would help perhaps in understanding the statement.

Kind of like extension cord verses 12/3 SJOOW cable. One is a broad term, the other specic to what it is.


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## starksk (Jul 20, 2010)

Shawncfer said:


> What the!!! Cat.5E???
> 
> What is that?!? I mean, I look at is as ethernet cable, not Cat.5E or Cat 3... someone help me out!



See: Template:UTP Cable Standards - Wikipedia, the free encyclopedia

The category (Cat.) refers primarily to the speed of transmission and amount of data the wire can handle.

Ship's post refers (slightly off topic) to the use of Category 5e or better wire to run hardline DMX. Your previous questions refer more to the protocols used to continuously transmit packets of lighting control data (EDMX, sACN, etc...). While your installation might use Cat. 5e cable in the wall for your hardline DMX, you likely will not have to worry about it if it was properly installed.


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## Shawncfer (Jul 20, 2010)

Okay, So what kinda of cable SHOULD be installed already vs. what ship is talking about?


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## starksk (Jul 20, 2010)

Shawncfer said:


> Okay, So what kinda of cable SHOULD be installed already vs. what ship is talking about?


 
Cat 5e and up is acceptable for installation. We recommend Belden 9729 (or equivalent) for DMX because it is shielded and more robust that Cat 5, but in installation where it is run in *Grounded* conduit, you are not likely to see performance loss assuming it is properly terminated.


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## Shawncfer (Jul 20, 2010)

So the kind of ethernet cable used for instalations like that and stuff I could also use for my computers at home???

Oh and another question.. How come when ever I hook up a multiparamater fixture from a dmx wall output I have to terminate it at the end, but when Im not using the wall output it doesnt have to be terminated???


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## ajb (Jul 20, 2010)

Shawncfer said:


> So the kind of ethernet cable used for instalations like that and stuff I could also use for my computers at home???



An ethernet cable is an ethernet cable*, it will work in your ethernet lighting network just as well as in your ethernet home computing network.

Did you mean to ask if you could use the kind of _DMX_ cable that's used for installations for your computers?

If so, more like the other way round. Belden 9729 and such tend to be two-pair shielded twisted pair, ethernet uses 4-pair Category 5, 5E, or 6 twisted pair (usually unshielded, but it can be shielded in particularly noisy environments). The Category indicates some electrical aspects of the cable, such as the characteristic impedance and rate of twist in the pairs. Cat 5/5E are 'close enough' to DMX cable in these respects to work, but IIRC Cat 6 is not recommended. So since each DMX network only needs one twisted pair plus common, you can pack up to three DMX signals into one piece of 4-pair 5/5E if you use one of the pairs as a shared common and the other three pairs for one DMX universe each. 10Mbit and 100Mbit ethernet use only two twisted pairs, so you could actually fit them on a two-pair DMX cable, but performance will suffer since even 10Mb ethernet runs at 20Mbaud, as opposed to DMX's 250Kbaud (in other words, ethernet uses much more rapid signalling that makes it more sensitive to cabling and other factors). 1000Mbit ethernet uses a full four pairs, and will have even greater issues if you attempt to use it over improper cable. 


> Oh and another question.. How come when ever I hook up a multiparamater fixture from a dmx wall output I have to terminate it at the end, but when Im not using the wall output it doesnt have to be terminated???


 The end of a DMX chain furthest from the signal source (whether that source is a console, optosplitter, or ethernet-DMX node) should be terminated to prevent signal reflections from confusing any receiving device on that chain. If there is no receiving device present, there is nothing to get confused, so there's no need for a terminator.

---------------
* This is disingenuous. There are dozens of standards for the physical layer of Ethernet with transmission speeds from 5 Megabit up to 100 Gigabit, and the cables used range from coax to fiber optic. Usually when we say "ethernet cable", we mean a 4-pair Category 5, 5E, or 6 UTP cable with 8P8C (aka RJ45) connectors since that's what's required for the most common forms of ethernet that an end-user of any sort will encounter.


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## jowens (Jul 20, 2010)

Les said:


> You have a valid point. Back when I was in high school, we had a fresh renovation (completed half way through my Freshman year) with motorized battens. It was great not having to worry about adding and removing weights whenever we'd do a new hang, but the kids at the cross town rival school were way ahead of us in educational regards because they had a counterweight system. Their school was relatively new, having been built in the '90's. Our technology and overall space was better, but they learned more rigging fundamentals than we did. Sure, there's always college, but some people don't go to college and instead choose to go straight in to the field. In their case, it would be nice to have learned the basics in high school rather than out on the job where time is money.
> 
> Hydraulic orchestra pits are nice, but are they necessary in a high school where it will only get used a couple times a year?


 
I tend to disagree. While the building I teach in has some great stuff, it is certainly not spectacular in its backstage capabilities (i.e. no motorized battens, no motorized pit, etc. etc.). The thought that a public school should not be progressive when given the opportunity is unfortunate, and not what the schools need.
I work hard to spend our limited budget to improve our space, just as many of us do, here on CB. If given the opportunity to offer my students and community a substantial upgrade and more of a space to be proud of, you bet I'd lobby to get every last thing (dollar) I could.
If a student comes out of a school only with the knowledge of how to operate their single piece of equipment, the teacher failed. What I love about teaching theater and theater tech is helping kids to become problem solvers, regardless of the equipment at hand. So many other places in the school teach kids to get 'the right answer' in the 'prescribed algorithm.' My kids learn concepts that will guide them regardless of the system used.

You can't fault a student whose community made an investment in their theater (often times, big jobs like this come in the form of community votes on a bond issue) and then tell him he should have worked on _regressive_ equipment. It really just sounds like jealousy. Often times public schools work to get new materials, infrastructure, computers, facilities, etc. so that their students are prepared for the future. One of the largest 'non-educator' complaint about education is about how our kids aren't prepared for the future. I think it's more of a problem solving issue. So, if a teacher with an aging system doesn't give opportunities to problem solve, their student is no better off than that of a teacher with a state of the art system with the same teaching methodologies.

So are the advanced technologies appropriate in high school? Of course; more of the question, however, is how are teachers working with kids to help them get a thorough understanding of what they're using and maybe what they're not using.

~Joe


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## epimetheus (Jul 20, 2010)

starksk said:


> Cat 5e and up is acceptable for installation. We recommend Belden 9729 (or equivalent) for DMX because it is shielded and more robust that Cat 5, but in installation where it is run in conduit, you are not likely to see performance loss assuming it is properly terminated.


 
Slightly off-topic, but why do you guys recommend 9729 (100ohm impedance, foil shield) verses something like 9842 (120ohm impedance, braided shield)? The 9842 is true RS-485 cable; it's the de facto standard for RS-485 runs in industrial installations.


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## millamber (Jul 20, 2010)

Shawncfer said:


> What the!!! Cat.5E???
> 
> What is that?!? I mean, I look at is as ethernet cable, not Cat.5E or Cat 3... someone help me out!


 
OK, so in as simple a form as I can make it (forgive me if I cover things you already know)...

DMX is based off of one host (console) sending data down a cable to other devices, which receive it in a daisy chain fashion. In one chain you can control up to 32 devices across 512 channels. this is known as a universe of DMX. The signal can be routed by an opto-splitter which takes in DMX and makes a number of new chains, while still holding to the same universe. A console will have anywhere from 1-4 universes onboard, depending on brand.

Ethernet protocol, by contrast, is more in the system layout than in what is connected to it. You can have ethernet jacks (RJ45) spaced all around the room. These jacks don't have a defined purpose like a DMX in connector would. They can change depending on what you plug into them. All that the jacks do is give you a way to get onto the network. They are, if you will, the bus stops where data gets onto or off of the network.

The ethernet cable (either Cat 5, Cat 5E, or Cat 6) connected to the backside of the jacks goes back to an equipment rack where it terminates into a patch panel. The patch panel then uses jumper network cables to connect to a network switch. The switch is sort of like Air Traffic Control, taking information in from one source and routing it to the proper source elsewhere in the system. It understands who is who by remembering (or assigning) IP addresses to all connected devices. An IP address is a ID tag for devices.

So, since the network simply routs information from one place to the next, all of the wiring is done in a Star type topology. All the information is sent to the switch which then sends it back out the appropriate line. That information can be any type of protocol really, allowing multiple users to talk to their particular devices, regardless of signal type. This is what ACN is, an Advanced Control Network that uses an ethernet backbone. In your case you are sending DMX information over that network.

The console is sitting directly on the network, sending channel information to the network. To get the ACN signal back to DMX, you would go through a gateway, basically a transformer that changes one type of signal into another. The gateways can be configured to start outputting DMX at any address. From there, it is DMX again, with fixtures daisy chaining off the chain. So your start address of the moving light can be 1-512 and the gateway can be configured to be any control channel, allowing you to control fixtures without having to worry about universes..

That is the basics, I'll fill in more after lunch if there are questions.


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## Les (Jul 20, 2010)

jowens said:


> I tend to disagree. While the building I teach in has some great stuff, it is certainly not spectacular in its backstage capabilities (i.e. no motorized battens, no motorized pit, etc. etc.). The thought that a public school should not be progressive when given the opportunity is unfortunate, and not what the schools need.
> I work hard to spend our limited budget to improve our space, just as many of us do, here on CB. If given the opportunity to offer my students and community a substantial upgrade and more of a space to be proud of, you bet I'd lobby to get every last thing (dollar) I could.
> If a student comes out of a school only with the knowledge of how to operate their single piece of equipment, the teacher failed. What I love about teaching theater and theater tech is helping kids to become problem solvers, regardless of the equipment at hand. So many other places in the school teach kids to get 'the right answer' in the 'prescribed algorithm.' My kids learn concepts that will guide them regardless of the system used.
> 
> ...



True, *a lot* of it hinges on the way the system is implemented and taught.

It's still a little sad though when someone knows how to program movers on an Ion, yet can't run a 2-scene preset on the fly. Not saying everyone needs to learn a preset, etc, but that sometimes the "latest and greatest" sometimes aren't the best teaching tools. Though preset boards are obsolete, they are still likely to rear their ugly head for years in to the future. Oh and it's not jealousy. I graduated high school (with a $9m performing arts space) years ago. These days I work in all kinds of venues, from ratty community theatres to multi-million dollar complexes. I totally agree with your philosophy, I just don't think a high school needs a ton of movers, etc.

I think the best way high school students can educate themselves if they're really serious about their art is to volunteer at a local community theatre over the summer. Truly excelling at what you do means having a knowledge base which is vast and flexible.


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## derekleffew (Jul 20, 2010)

millamber said:


> ...The Smartswitch is there to give you a large number of relays controllable by dmx. Yes, an R20 will do a similar job, but it is only 2 circuits per module, and you'd have to sacrifice a slot in your Sensor rack. The smartswitch allows for up to 48 relays per panel. Not to mention that it is less expensive than the equivalent number of R20 modules.


The other advantage of the SmartSwitch is that it can be used to provide the 208V that some MLs require, while the R20 is only 120V. Another use is to control 277V fluorescent lighting circuits.


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## jstandfast (Jul 20, 2010)

With regard to Vortek systems and their like in public schools; it's useful to bear the legal system in mind. The idea that systems like this do not involve teenagers throwing stage weights around @ great height ( or being under others who are ) is mighty attactive to administators who have to worry about liability issues.


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## fredthe (Jul 20, 2010)

jstandfast said:


> With regard to Vortek systems and their like in public schools; it's useful to bear the legal system in mind. The idea that systems like this do not involve teenagers throwing stage weights around @ great height ( or being under others who are ) is mighty attactive to administators who have to worry about liability issues.


There are two other reasons that I've seen for these types of systems in schools... there is less structural load than a counterweight system, and they are ADA compliant.


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## starksk (Jul 20, 2010)

epimetheus said:


> Slightly off-topic, but why do you guys recommend 9729 (100ohm impedance, foil shield) verses something like 9842 (120ohm impedance, braided shield)? The 9842 is true RS-485 cable; it's the de facto standard for RS-485 runs in industrial installations.



From the true geniuses (including CB Member DavidNorth):

> Each 9729 pair has an individual drain wire(for the common) and foil shield. Because of the drain wire and foil shield, it is much easier to dress and terminate than braided shielded cable. With a braid, you can either cut it off and solder on a drain wire or unbraid it down to a small portion of the shield. Both consule time and cause frustration.


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## Shawncfer (Jul 20, 2010)

millamber said:


> The console is sitting directly on the network, sending channel information to the network.


 
Okay, so on the picture I posted originally where theres the blue thing with all the ethernet cables going out of it (btw whats that thing called again?) theres two etherenets plugged in at the end seperate from all the others. I think those two would be the two light boards correct? (one black box one main stage). And so if the light boards are just in the same network, then theoretically I could move those ethernet cables around and it wouldn't matter because it's still on the same network correct? And also going by that, The ethernet outs that connect to the gateways which turn it into dmx, could I also plug my lightboard into the same ethernet input and it would still work because it's still on the network? Or are there special ethernet inputs for the lightboard? And seperate ones for DMX devices?

And that answers one question. I just don't understand whats so special about cat5 or cat5e or cat6.

Today I noticed that there wass one of the outputs (or inputs?) of ethernet labeled "Lighting Network" that the company hadn't quite screwed into the wall yet. So I tooke a look at the cabled attatched and it says CAT6... Then, we also recied a box from the company th a bunch of extensions, twofers, and other crap, including ethernet cable. But that ethernet was labeled CAT5e.. So is that okay?


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## ajb (Jul 20, 2010)

Shawncfer said:


> the blue thing with all the ethernet cables going out of it (btw whats that thing called again?)



Dude. . . that was answered in this very thread. The answer was on the page where you typed this post. Hint: it was very close to the top of the thread.


> theres two etherenets plugged in at the end seperate from all the others. I think those two would be the two light boards correct? (one black box one main stage).



Could be. If they aren't labeled you could unplug them and see what happens. 


> And so if the light boards are just in the same network, then theoretically I could move those ethernet cables around and it wouldn't matter because it's still on the same network correct? And also going by that, The ethernet outs that connect to the gateways which turn it into dmx, could I also plug my lightboard into the same ethernet input and it would still work because it's still on the network? Or are there special ethernet inputs for the lightboard? And seperate ones for DMX devices?



Depends on how the blue thing is configured--some ports on it might be set up to behave differently, or be disabled entirely if they aren't needed. Probably all the ports are active and operating normally, though.


> And that answers one question. I just don't understand whats so special about cat5 or cat5e or cat6.



What's special about it is that the explosion of computer networking has made Ethernet infrastructure cheap and ubiquitous. Just about any electrical contractor knows how to install it or someone he can sub it to. There are tons of products out there that make it cheap and easy to implement on devices like dimmers and lighting consoles. And it can carry far and away more data than DMX ever could, more reliably. This ubiquity has also encouraged other products to take advantage of it, so for example if you have a big video element in a show, you can unpatch a couple of those UTP runs and use them to carry video if you wanted (with the right adapters). Or you use them with various other products in lieu of a massive audio snake from the stage to the booth. And you can do all of this on the same thoroughly standardized, inexpensive infrastructure with a huge degree of flexibility and room for expansion. 


> So I tooke a look at the cabled attatched and it says CAT6... Then, we also recied a box from the company th a bunch of extensions, twofers, and other crap, including ethernet cable. But that ethernet was labeled CAT5e.. So is that okay?



It's fine. Cat6 is preferred for higher speed Ethernet (1Gb+), but 5 and 5E will be just fine for up to 1Gb. It's common to spec up infrastructure cabling beyond what is currently required since it's so expensive to replace down the line. If you find yourselves needing 10Gb in a few years, it's easy to throw away that 5E patch cord and replace it with Cat6, and replace that blue thing with a shiny new 10Gb blue thing. . .it would be MUCH more expensive if you had to replace all of the fixed wiring, so the Cat6 is basically just a bit of future proofing.


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