ETC Sensor Installation Racks

rochem

Well-Known Member
Just a simple question here. At my school we have two Sensor Installation Racks in the Dimmer Room off SR. Keeping in mind that these are permanently installed racks and not touring racks, is it possible to plug a DMX line directly into the racks, to go into a small console on deck to use for focusing? The DMX line from the rack to the booth is run through the walls somewhere up to a port in the booth. Is the DMX connection at the rack something that can just be unplugged, or is it somehow internally located within the rack? Hope that makes sense.
 
Short answer:
Nope, you can't...at least not in the way I imagine you want to accomplish this.

Long answer:
The DMX wiring going into (and out of) the rack or racks is "hardwired" into the rack itself and not terminated to an internal 5 pin DMX receptacle that you likely could easily repurpose.

If another input receptacle wasn't installed when the system was designed and installed into your space....and *depending on your system specifics*, it may be possible to install another DMX input jack and run an install-spec DMX cable into the rack for this purpose...but that would be something a qualified person would need to assist you with because of the terminations and possible configuration changes to your processor/system.

Abby
 
Short answer:
Nope, you can't...at least not in the way I imagine you want to accomplish this.

Long answer:
The DMX wiring going into (and out of) the rack or racks is "hardwired" into the rack itself and not terminated to an internal 5 pin DMX receptacle that you likely could easily repurpose.

If another input receptacle wasn't installed when the system was designed and installed into your space....and *depending on your system specifics*, it may be possible to install another DMX input jack and run an install-spec DMX cable into the rack for this purpose...but that would be something a qualified person would need to assist you with because of the terminations and possible configuration changes to your processor/system.

Abby

Yea, that's unfortunately the answer I was expecting to hear. This isn't so critical that I would call in a qualified person to do, it would just be a nice convenience. Thanks for the quick reply.
 
Why couldn't you just add a 5-pin XLR male and female pair in line with the existing cable?
/mike

Well, first of all, the OP said that the data lines into the rack are in conduit, so adding a connector would be hard. Also, splitting your primary run to your dimmers is probably not the best idea. It only takes one time of forgetting to plug it back together or one dumb person to unplug it during a show to ruin a production.
 
Sensor CEM's have two DMX inputs. If the second input is not being used, it could be done. It would just be a matter of installing the jack and cabling it back.
 
YOU WOULD NEED AN ELECTRICIAN FOR THIS, but one idea is to break into the conduit, and add a two-port DMX hub (IN-IN-OUT). The one port is permanently running back to the booth, the other is open for on-stage work, and the OUT runs to the rack(s). The only big issues are breaking the conduit line (hopefully it is surface run) and locating the hub (make sure it can't be easily tampered with, maybe locate it in an oversize electric box). Again, this may be more trouble than it is worth, but it is an idea.
 
If your going to go through the trouble of chopping thru a conduit, your gonna need to pull new line anyhow because it probably wont be long enough to tail out to a splitter (unless the installer included extra loops at the ends), so you might as well just pull in a few more DMX lines, maybe a 2nd universe, and put the splitter in the booth instead, so you can always have a dmx lineout to the stage?
 
At the Pageant we have three different locations that we run lights from. The first is at the back of the loge, where we run lights during rehearsals. The second is off stage left where we run lights for focusing. The third is up on the mezzanine level off stage left. We used to simply re-patch the dmx depending on where we were running lights. A few years back I reconfigured our dmx so that all three dmx lines from our control locations were permanently run in conduit to a dmx combiner unit. This allows us to put the light board wherever we need it without having to re-patch the lines. However, dmx combiners are not cheap, so whether this is a viable solution in your situation is debatable. Given the expense, this solution would probably work best as part of a wholesale reconfiguring of your school theatre's dmx setup.
 
On our stage we have a jack for the RFU, which to my knowledge nobody that uses the theatre knows that it exists. My question is could that be used to expand to other dimmers or lights or is just for focusing? The board is an Expression, which I have used a little but not often. Most times we go in we disconnect the board and use ours.
 
On our stage we have a jack for the RFU, which to my knowledge nobody that uses the theatre knows that it exists. My question is could that be used to expand to other dimmers or lights or is just for focusing? The board is an Expression, which I have used a little but not often. Most times we go in we disconnect the board and use ours.

I don't know what the protocol is for RfU-Console communications, but it is just used to send control signals to the board, and the board processes the control signal and outputs DMX to your racks. Easiest solution for bringing the board to the stage is to run a DMX cable to the booth(or other DMX input location).
 
If you have an ETC board that is relatively modern, grab your iPod touch and use that. Heck of a lot less expensive than all the other methods, or find the RFU for your board, and use that. Saves you the hassle of moving the board.
 
On our stage we have a jack for the RFU, which to my knowledge nobody that uses the theatre knows that it exists. My question is could that be used to expand to other dimmers or lights or is just for focusing? The board is an Expression, which I have used a little but not often. Most times we go in we disconnect the board and use ours.

In all likelihood, the jack for the RFU is a 7 pin XLR (can't remember the ETC wired RFU pin config. ?), but in any case, it's not a 5 pin DMX connection. At the console end is a similar port that probably has a cable connecting to the console RFU port. In theory, you can get 5 pin to 7 pin XLR adapters made that would allow you to use the RFU cable already running in the system, as a DMX line. That gets you the 2nd or 3rd port off the Expression to use as DMX on the deck. Kirk Stark or somebody else at ETC can confirm, but I believe the RFU cable is DMX compliant, though generally not used for that type of data connection. And as a thought - will a 5 pin DMX connector plug into a wired RFU port, whatever the pin configuration ?.

You could also do a connection that sends DMX data up the now-disconnected-from-the-Expression RFU cable, and send DMX back down the DMX line that you disconnect from the existing console to send DMX to the dimmers -IF there was no other DMX port into the dimmers on deck.

This is not at all a typical method of operation and one I would usually not recommend to a facility operating without a technician in charge that understands the way the system(s) function. It is only a work around to use un-used in the wall cables.

SB
 
If you have an ETC board that is relatively modern, grab your iPod touch and use that. Heck of a lot less expensive than all the other methods, or find the RFU for your board, and use that. Saves you the hassle of moving the board.

To expand. It needs to be an Eos, Ion, Element, Congo or Congo Jr console in order to have a WiFi connection that an iPod can talk to. You will need a WiFi router and the knowledge to get it working on the console, as well as the $50 ETC iRFR application.

SB
 
For pinouts and cable specs for Express(ion) and Obsession wired units, see the ETC wiki entry RFU. As SteveB said, it's possible to use the in-wall RFU wiring as an in or out, you'd just need to build the appropriate adaptors. Don't wire anything to pin 6, as that one carries voltage.


Note to ETC wiki authors: The following is confusing,
Note that there are two variants of six pin XLR, one of which - "Switchcraft Type" - is symmetrical, the other of which - "Neutrik Type" is not symmetrical. It is important to ensure you use the correct type if repairing an RFU or making an extension cable.
RFUs use the "Switchcraft Type" XLR.

As it says the RFU uses the Switchcraft, gray-insert, "symmetrical" pin configuration; yet the diagram,
proxy.php


shows the non-symmetrical, black-insert, "Neutrik" configuration.
 
Quote:
Originally Posted by shiben
If you have an ETC board that is relatively modern, grab your iPod touch and use that. Heck of a lot less expensive than all the other methods, or find the RFU for your board, and use that. Saves you the hassle of moving the board.

To expand. It needs to be an Eos, Ion, Element, Congo or Congo Jr console in order to have a WiFi connection that an iPod can talk to. You will need a WiFi router and the knowledge to get it working on the console, as well as the $50 ETC iRFR application.
Yes, one of those. I dont recall if the OP has one of those or not, but if they do, 50 bucks is probably going to be cheaper than most of the other options, especially if we are talking about cutting open a wall and putting in a DMX splitter and whatnot, even getting an iPod touch and the app would probably be cheaper. However, if that is not the case, turning around the RFU cable is going to be the best option. 2 new wall mount 5 pin XLR jacks, 1x 2 foot DMX cable, 1x 30 foot DMX cable for on stage, and a soldering iron and your in business. I actually checked on this, and at least our old RFU line is DMX compliant, so yours might be too.
 
If you have an ETC board that is relatively modern, grab your iPod touch and use that. Heck of a lot less expensive than all the other methods, or find the RFU for your board, and use that. Saves you the hassle of moving the board.

Nope. The venue I was referring to was my high school, and we're currently running an Express 48/96, so no WiFi. We also don't have a RFR, as one didn't come with the console and we've never needed one enough to justify the cost. Similarly, anything requiring a certified electrician is basically over where I can go with it - if there was a simple plug-and-play solution that I could do in 30 seconds that would be perfect, but since it's not it looks like we're just gonna have to live with running back and forth from the booth.
 
Okay, it seems that this thread took a slight detour into the world of "just because you can, doesn't mean you should..."

Kirk Starks or somebody else at ETC can confirm, but I believe the RFU cable is DMX compliant, though generally not used for that type of data connection.

If the wire was pulled according to ETC Spec (Belden 9728 or approved equal), the only difference with the RFU cable would be the extra set of conductors and shielding. Technically, RFU uses the same type of underlying data protocol (RS-485) that DMX uses, so data transmission down the pairs would not be a problem.

One thing to remember is to make sure that the adapter is wired correctly.
Don't wire anything to pin 6, as that one carries voltage.
You would actually want to make sure that you do more than that and make sure that you wire on a shared twisted pair.
...will a 5 pin DMX connector plug into a wired RFU port, whatever the pin configuration?
Some 5 pin connectors do fit in the RFU ports supplied by ETC. However connecting DMX straight into a RFU port will split the Data+ and Data- onto different sets of twisted pairs.
You would want to wire pins 2 and 3 of the DMX connector to pins 2 and 1 respectively of the RFU connector.
The next problem that comes into play is the common/shield. In DMX, the shield is a part of the specified cable and is wired to Pin 1. In RFU, the common is specified as a seperate conductor. That seperate conductor, like the +12VDC line, doesn't need to follow the rules of a daisy chain topology, it only needs to be connected together. While it is uncommon to home run those conductors while daisy chaining everything else, it has happened in the past. What that means: you may get flickering or unusual behavior connecting the shield of DMX to the common of RFU. Therefore, you may wish to connect it to either pin 3 or 4 of the RFU connector to maintain the daisy chain.

Which ever way that you choose, be consistant.

You could also do a connection that sends DMX data up the now-disconnected-from-the-Expression RFU cable, and send DMX back down the DMX line that you disconnect from the existing console to send DMX to the dimmers -IF there was no other DMX port into the dimmers on deck.

This would be the preferred method of this type of jury-rigging of the system as, with the properly built adapters, it would allow you to transmit DMX to your dimmer rack from the stage, force you to disconnect the Expression from the RFU line reducing chances of RFU voltage being directed to the DMX line (and thus into the dimmer rack), and make it unlikely that someone would leave it this way accidentally for a show or other time you needed to use the Expression in its home location.

However, if that is not the case, turning around the RFU cable is going to be the best option. 2 new wall mount 5 pin XLR jacks, 1x 2 foot DMX cable, 1x 30 foot DMX cable for on stage, and a soldering iron and your in business.
I would only recommend this if you:
A. are never going to use your RFU again anywhere in your system (except maybe directly connected to your console), and
B. you know the wiring layout of your RFU runs to know where the actual start and stop of the daisy chain is, and
C. you change all of the connectors to the appropriate connector type (one output, the rest as inputs)

This is not at all a typical method of operation and one I would usually not recommend to a facility operating without a technician in charge that [fully] understands the way the system(s) function. It is only a work around to use un-used in the wall cables.
Emphasis added for agreement.

And finally, after my novel of a response, Derek:
Note to ETC wiki authors: The following is confusing...
I'll take a look at that soon, but as it is a open wiki, if you happen to find a less confusing picture, feel free to post it ;)
 
Sorry for confusing the thread. The OP wanted to tap into his Sensor dimmers. I have a theatre that I am doing a fairly complex show where I will be adding about 80 additional lights. That means I will need to add dimmers and wondered about jumping in through the RFU jack. I didn't want to move the board. I'll just run a cable down from the board, not a problem.
 

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