Can't remember exactly, but it might be either ETC RFU cable (I think that's 6 pin XLR), or possibly Sensor to Console Link cable. Not sure why you would have Link cable in anything over 20ft, which would be sufficiant to go from a booth wall plate to a console, as generally it's hard wired to the racks. Might be for a touring system that wanted the Link system operational.
Could also be a 2 channel com system cable. Telex has 6 pin on all of there 2 channel packs.
The loop hole to the standard was that the manufactuers could put 3 pin on and call it DMX if they supplied an adapter, so people just put on the 3 pin and forgot about supplying the adapter. The real deal was that production houses did not want to stock an extra cable when they had plenty of 3 pin connectors and cable laying around.... even though hardly any of it was meant for data.To be excruciatingly precise, the ONLY cable that is truly dmx is 5 pin twisted pair shielded. This according to the USITT standard updated a couple years ago.
4 pin scroller cable is not dmx, although it is used in lighting. As is 3 pin xlr, and perhaps 6 or 7 pin. Or cinch-jones. And all the others. Theoretically, 3 conductor extension cords could carry dmx data. So while it is possible that any cable carries a dmx signal it is not truly dmx standard unless it is 5 pin xlr twisted pair shielded cable.
Doesn't the RFU have 6 pins but one pin is a center pin? I haven't have an ETC RFU for a few years so I can't really remember. I also remember the ETC link cable having a center pin or two. I do know that you can plug the DMX cable into the RFU output on ETC consoles, that tripped me up a few times when I let someone else run the DMX...Should anyone ever need to order 6pin XLR plugs and connectors, be aware there are two pin configurations, and they are not compatible with each other. One has the pins arranged symmetrically, the other does not. I believe the ETC RFU (Expression family) uses the non-symmetrical, and Telex and CLearCom use the symmetrical, but I might have that backwards.
The biggest disadvantage to DMX is that it works like a boss shouting orders who doesn't listen to anyone! If someone doesn't hear him right, they go out and do the wrong thing! (Thus BAD for Pyro.) Technically, this is known as "error check" which DMX does not have. As far as the extra pins go, people who write standards like to allow for things that sometimes don't happen. Ethernet has 8 pin connectors, and 8 conductor cabling but only uses 4 wires. So, some have adopted a 3 pin system with DMX and it works fine if you are using all 3 pin fixtures. Others have used the second pair for a second DMX universe, doubling the amount of channels it can handle. But it was said before. The standard is 5 pin, and anyone who uses the extras to do something like feed power is no longer on the standard, and probably asking for trouble!
Though wireless is nice, it is kind of moot since you need to run power to the fixtures anyway, though I suppose we do have W-DMX...What do we think about the possibility of ACN and data in general being delivered wirelessly inside a venue? No need to connect anything besides power. I see the clear advantages of wires over wireless whenever possible, but I think it'd be an interesting idea. This one is pretty stupid, but what if data and power were integrated into a single connector? That would be kinda weird...
Yeah, many people have tried power and data in the same cable for several different applications.
Whats going to kill people with ACN is the fact that you can't daisy chain but have to do a point to point for each fixture. Couple that with the 300' limitation and there are going to be some issues. Fiber snakes will become the norm simply because they will have to. I HIGHLY encourage anyone who is wanting to get into any type of technical theatre to go get their CCNA. I should have mine (took the class, never had the time to take the test.... or I am just lazy.. you pick). I can not tell you how much having that class has helped me. When these networks get larger data systems are going to have to grow. I see in the future a gigabit fibre backbone going to each truss breaaking out into cisco switches that will take copper to the fixture. Ethercon connectors on everything... yadda yadda yadda.It's been touched on but not really clearly... The original purpose for those two extra pins was for information from the device to be returned back to the console. There are a few applications where this is going on right now but EXTREMELY limited.
As for the future of DMX. It is on the way out BUT it will be VERY slow. ACN and Ethernet based control is coming very soon. While we wait for ACN to be fully adopted we are in a period of proprietary ethernet languages. New Consoles have been coming out with both ethernet and DMX jacks for a year or two... I believe EOS is the first to ONLY have ethernet jacks (right?) I'm not sure what intelligent gear has ethernet jacks just yet but it won't be long until it all does. There are a lot of advantages to the user of ethernet based control, #1 being the cable is far cheaper.
My new theater is Strand based so it will "talk" Strand's proprietary ethernet language from the console to the dimmers and back. The Strand language goes out over the ethernet system of the theater to the DMX nodes. The nodes translate it into DMX and from there it's DMX cable to my gear. In the future my console and dimmers will be upgraded to speak ACN If I am able to purchase gear that speaks ACN there will be no need for the nodes, or the expensive DMX cable. Everything will speak ACN and connect via ethernet cable.
To me, the best part of the future is RDM. With RDM we will no longer need to set DMX addresses. The gear will identify itself to the network and talk back to the console. You'll be able to plug in a bunch of gear hit a button and it will all find itself in the network. Much like plugging in a USB device to your computer today.
When will we all have ACN? About the time Charc retires. ACN and RDM are realities that will be implemented soon. The technology is here and the manufacturers just have to go through the process of implementing it. However the question is, can your theater afford to switch when your DMX system is working just fine? Yeah that's what I thought. My guess is in about 5 years the vast majority of new purchased gear will no longer be DMX based. Gradually as systems go down ACN will replace DMX. So it'll take a good 15-20 years until most of us make the switch to ACN. Then it'll be another 15-20 years after that until the "cinch jones" club (little community theaters, schools, and churches) give up their ancient gear and upgrade to ACN equipment. DMX is dead technology... but she's going to take a REALLY long time to die so get used to her.