# Cat 5 for DMX in the wall wiring



## Johnparmalee (Oct 19, 2009)

Greetings, John here, lights and backdrop guy for Faithbridge in Spring (NW Houston), TX

Will Cat 5 work for in the wall wiring for DMX? I understand the 120 ohm situation. I can't find the impedance and for sure understand the no mic cable situation.
If not Cat 5 in the wall what is a good cable to put in the wall?

JP


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## Esoteric (Oct 19, 2009)

I use CAT5 for all my permanent installs where there not going to be a lot of electrical interference.

Mike


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## derekleffew (Oct 19, 2009)

Category 5 cable is an excellent alternative to traditional DMX cable for in-wall applications (provided it is inside conduit) and the practice is actually recommended in Nick Mobsby's book, _Practical DMX_. 

See also ANSI E1.27-2 - 2009:Entertainment Technology - Recommended Practice for Permanently Installed Control Cables for Use with ANSI E1.11 (DMX512-A) and USITT DMX512/1990 Products from ESTA's Technical Standards Program.


Outside the wall and for Portable Control Cables? Not so much. Some reasons: Most RJ-45 connectors are delicate and not designed for repeated mating cycles, 22 AWG solid cable is fragile, and kinks easily when coiled. Most A/V companies that use long runs of it for video purposes test it before every use. There's no cost-benefit to shielded, stranded, ruggedized UTP cable over say a Belden 9842 (pdf). From Belden's document:

> A third cable alternative is Category cables, such as Category 5e, or 6. These are most often UTP, unshielded twisted pairs. Their impedance (100Ω) puts them reasonably close to the 120Ω of RS-485. Further, while they can run DMX-512 today, there is a lot of work being done to use the Ethernet® networking protocol for DMX-512. That would mean that Category data cables installed today to run DMX-512 could also run Ethernet tomorrow. It also means that the same cable type could be used for both Ethernet and DMX-512 applications. There are dozens and dozens of UTP Category cables that might be considered for DMX-512.


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## Johnparmalee (Oct 19, 2009)

Thanks 

JP 
Faithbridge


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## STEVETERRY (Oct 19, 2009)

Johnparmalee said:


> Thanks
> 
> JP
> Faithbridge



Don't forget that category cables with solid conductors can only be reliably terminated into insulation-displacement (vampire tap) wiring devices intended for the purpose. 

Don't strip the cable and terminate to compression screw terminals, crimps or solder joints--that will cause big reliability issues!

ST


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## derekleffew (Oct 19, 2009)

STEVETERRY said:


> Don't strip the cable and terminate to compression screw terminals, crimps or solder joints--that will cause big reliability issues!


The dickens you say? Works fine with every phone jack in my house. What about P-nuts?


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## JD (Oct 19, 2009)

Cat 5 is 8 conductors in four pairs. When using it for DMX, one pair is connected to pins 2 & 3. If you are using 5 pin DMX, the second pair should go to pins 4 & 5. The other two pairs (all 4 wires) should all go to pin 1. Keep your polarity consistent. Never parallel a pair! Only one wire each on pins 2,3,4,5. If you one of those crazy rebels using 3 pin, all unused wires should go to pin 1. 

When used in building wiring, the conduit itself serves as a shield. Never run it in a conduit that contains building power! 

Now, on to the "Opinion" section  :

1) The Cat line should be the ONLY wire in the conduit. 

2) You may have problems finding XLR wall mount connectors with insulation displacement terminals. I have not run into issues using the solder type connectors. Just remember, you are making a connection that runs at RF frequencies, workmanship is important. 

3) Now, my most controversial point: Outside of the wall, don't use Cat cable. Not only is it fragile, it's not shielded. This post will probably be followed by a half dozen posts from people who have no problem with it. I'm glad for them! I, however, will never do it.


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## Esoteric (Oct 19, 2009)

I am with you JD. I only use the recommended Belkin cable outside of walls (unless I run in conduit then I will use CAT5 even outside the wall).

Mike


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## STEVETERRY (Oct 19, 2009)

derekleffew said:


> The dickens you say? Works fine with every phone jack in my house. What about P-nuts?



How lucky do you feel? 

When there's an unplanned blackout, I'll give the audience your number. Oh wait, your phone might not be working due to broken wires. 

Seriously, the problem is with stripping the Cat5 without nicking it, making it subject to future fracture. Might work, might not. Why take the chance? Be conservative. The audience will like you for it.

FYI, ETC makes a CAT5 insulation displacement XLR-5 wall mount, and perhaps others do as well.


ST


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## cdub260 (Oct 19, 2009)

STEVETERRY said:


> The audience will like you for it.



But I don't want the audience to like me. As a matter of fact, most of the time I don't want them to even know I exist.


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## fredthe (Oct 19, 2009)

derekleffew said:


> Outside the wall and for Portable Control Cables? Not so much. Some reasons: Most RJ-45 connectors are delicate and not designed for repeated mating cycles, 22 AWG solid cable is fragile, and kinks easily when coiled.


There's always Belden 1305A Belden Featured Product
Stranded, and I'm told it can be driven over without damage.
Of course, it's not cheap, either.

-Fred


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## renegadeblack (Oct 20, 2009)

We have one run of CAT5 outside of the wall, and that's to use a Leviton 1000 as an RFU... in other words... nothing high stakes.


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## JD (Oct 20, 2009)

fredthe said:


> Of course, it's not cheap, either.



Of course, neither is standard DMX! Looks like good cable. Seen it listed before but never tried any. Again, the shielding issue is the thing for me.


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## fredthe (Oct 20, 2009)

JD said:


> ...it's not shielded. This post will probably be followed by a half dozen posts from people who have no problem with it. I'm glad for them! I, however, will never do it.


OK, I'll bite...

In my experience, both with DMX in fairly simple setups, and with RS-485 in high noise environments, unless your practice is to wrap your DMX cable around one leg of your 400A feed, or to *not terminate your DMX*, then the shielding isn't necessary.

Now, I will agree, in situations with marginal connections or unterminated connections, the shielding *may *afford you some additional level of reliability.

-Fred


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## tcahall (Oct 20, 2009)

I generally agree with the above. One note, sheilding is great as long as shield continuity is maintained throughout the system and correctly installed AT EVERY POINT in the network. One open shield point or a ground loop through your system can make life real exciting on the test set.

Tim


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## FMEng (Oct 21, 2009)

STEVETERRY said:


> Don't forget that category cables with solid conductors can only be reliably terminated into insulation-displacement (vampire tap) wiring devices intended for the purpose.
> 
> Don't strip the cable and terminate to compression screw terminals, crimps or solder joints--that will cause big reliability issues!
> 
> ST



I beg to differ. It's not the type of wire, it is the workmanship of the termination that counts. Use the wrong strippers, or make a cold solder joint, then yes it will be unreliable. Done properly, any of the methods mentioned above will work long after we're dead and gone.

By the same token, I can make a very unreliable RJ-45 termination by simply using plugs designed for stranded wire on solid conductors. The clear RJ-45s are ONLY for use on stranded wire. Smoke colored ones are designed for solid conductors. Pick the wrong one and all bets are off about it working without intermittent problems. This seems to be a well kept secret. I often see the connectors used on the wrong kind of cable with disastrous results.


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## fredthe (Oct 21, 2009)

FMEng said:


> By the same token, I can make a very unreliable RJ-45 termination by simply using plugs designed for stranded wire on solid conductors. The clear RJ-45s are ONLY for use on stranded wire. Smoke colored ones are designed for solid conductors.


That's the first I've ever heard of smoke color connectors being the only ones for solid conductors. Can you point to a standard or a reference for this?

-Fred


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## mrb (Oct 21, 2009)

the smoke colored connectors must be specific to a manufacturer. I have clear ones for solid wire (three prongs to pierce the conductors insulation -these are the best kind)

I agree about this being a well kept secret. I constantly come across people who are convinced theyre god's gift to network wiring using the wrong crimps


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## JD (Oct 21, 2009)

Insulation displacement connectors and RJ45s were adopted by telecom companies because they are incredibly reliable with very little training needed making them perfect for use in wiring the nation's phone system! However, what works in one industry may not work well in others. Generally, you don't have to worry about connectors being run over repeatedly by hand trucks, or plugged and unplugged 10,000 times when working with phone equipment. In the entertainment industry, you can almost bet on that treatment! (thus the love of the metal covered XLR connector.) Telecom stuff works great in the wall, but not out where the humans are romping about.


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## GT3 (Oct 23, 2009)

this is all interest stuff because i'm fitting out DMX cable runs with stranded cat5e STP (shielded twisted pair) for an Auditorium on metal cable trays along side other audio and video cables so i hope it all works out all right but have been told by others who have done it and it does works well. The cat5e STP is about double the price of standard cat5e. 
Cheers, GT


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## derekleffew (Oct 23, 2009)

JD said:


> Cat 5 is 8 conductors in four pairs. When using it for DMX, one pair is connected to pins 2 & 3. If you are using 5 pin DMX, the second pair should go to pins 4 & 5. The other two pairs (all 4 wires) should all go to pin 1. Keep your polarity consistent. Never parallel a pair! Only one wire each on pins 2,3,4,5. If you one of those crazy rebels using 3 pin, all unused wires should go to pin 1.


There are many "standard" pinouts. I believe below is the most common, and the one specified by ANSI E1.27-2 - 2009:Entertainment Technology - Recommended Practice for Permanently Installed Control Cables for Use with ANSI E1.11 (DMX512-A) and USITT DMX512/1990 Products .

Pathway Connectivity Inc. - Cat5 Pinout for DMX.
1. Data 1+
2. Data 1-
3. Data 2+
4. Not Assigned
5. Not Assigned
6. Data 2-
7. Data Link Common (0V) for Data 1
8. Data Link Common (0V) for Data 2


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## Jay Ashworth (Dec 16, 2016)

FMEng said:


> I beg to differ. It's not the type of wire, it is the workmanship of the termination that counts. Use the wrong strippers, or make a cold solder joint, then yes it will be unreliable. Done properly, any of the methods mentioned above will work long after we're dead and gone.
> 
> By the same token, I can make a very unreliable RJ-45 termination by simply using plugs designed for stranded wire on solid conductors. The clear RJ-45s are ONLY for use on stranded wire. Smoke colored ones are designed for solid conductors. Pick the wrong one and all bets are off about it working without intermittent problems. This seems to be a well kept secret. I often see the connectors used on the wrong kind of cable with disastrous results.



Just to cloud the issue... 

My vendors have all used clear for solid-wire icecubes -- the ones where the IDC tines go along the conductor. Stranded-wire icecubes, where the tines go across the conductor, were the smoke colored ones.


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## microstar (Dec 18, 2016)

Pathway makes XLR DMX wall plates with IDC or RJ45 terminations. Amphenol makes the AC#MIB 3pin XLR cable connector with IDC termination.


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## VRommel (Dec 19, 2016)

microstar said:


> View attachment 14150
> 
> Pathway makes XLR DMX wall plates with IDC or RJ45 terminations. Amphenol makes the AC#MIB 3pin XLR cable connector with IDC termination.



Good Morning!

Yes, we do offer DMX512 wall plates with IDC termination for "category" wire. We also offer IDC termination for our rack-mount repeater and gateway products as well as for our DIN-mount interface, splitter and gateway modules.

I say this becasue we all need to keep in mind that if we are wiring to a DMX512 wall plate, that signal necessarily has to come from somewhere and the terminations there are of no less importance to system integritry than at the wall plate.

Our view of the future is that widespread use of "category" wire (solid and/or stranded) is here to stay so let's all be careful out there.

Best Regards,
Pathway Connectivity


Van Rommel
Director Business Development


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## Jay Ashworth (Dec 19, 2016)

So, do you also offer matching drop cords, with molded 8p8c plugs on one end, and 3- or 5-pin XLR's on the other? The "how do I terminate 22AWG copper to both an XLR and a modular" problem has merely moved outside the wall, not gone away...


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## VRommel (Dec 19, 2016)

Jay Ashworth said:


> So, do you also offer matching drop cords, with molded 8p8c plugs on one end, and 3- or 5-pin XLR's on the other? The "how do I terminate 22AWG copper to both an XLR and a modular" problem has merely moved outside the wall, not gone away...


Hi Jay:

No, we don't include drop chords of any type in our catalog.

We have seen a number of good products on the market that convert RJ45 to XLR5 and visa versa. 

Generally speaking, our position is that best practice is to keep the use of "category" wire inside the wall ( well maybe at the patch panel as well) and use the more robust jacketed shielded twisted pair cables fitted with XLR5 outside the wall. That best practice is going to be under assault as more and more fixture manufacturers move away from XLR5 and migrate to RJ45.

Best Regards,
Pathway Connectivity

Van Rommel
Director Business Development


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## Jay Ashworth (Dec 19, 2016)

Well, I don't disagree with that, but that leaves you with a solution that endusers *cannot* implement: terminating 18AWG stranded into an 8p8c.

As vendors start to put 8p8c jacks on gear for DMX, the problem will devolve to "what's the industry standard pinout", but for the nonce...


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## VRommel (Dec 19, 2016)

Jay Ashworth said:


> Well, I don't disagree with that, but that leaves you with a solution that endusers *cannot* implement: terminating 18AWG stranded into an 8p8c.
> 
> As vendors start to put 8p8c jacks on gear for DMX, the problem will devolve to "what's the industry standard pinout", but for the nonce...



Hi Jay:

There is an industry standard pinout. ANSI E1.27.2

This is my own personal opinion: When good adapters are available - and good adapters are available and more are coming to the market every day - use them to augment high quality manufactured cablling solutions when the rig requires.

Best,

Van


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## BillConnerFASTC (Dec 19, 2016)

OK - this confused me. In the wall - category wiring and terminations for it. Out of the wall, but also including the DMX receptacles that are in a wall plate for user use, XLR5. Where is the adapter normally needed?

(The only place I'm familiar with are the ETC products that have the RJ45 DMX in and out as an option or standard - I think just the ColorSource fixtures - options - or S-4WRD - only RJ45. I wish the relays were available RJ45, so an adapter was not needed if going that route.)


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## Jay Ashworth (Dec 19, 2016)

Sorry, Bill, I was distracted. We aren't talking about Walmount ethercon's, we're talking about wall mount 5 pins and I missed it.


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## sk8rsdad (Dec 19, 2016)

Some vendors, particularly in the LED architectural market but increasingly more of the low-cost LED providers are coming with RJ45 instead of XLR connectors. I guess they shave a few pennies off the price that way.


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## BillConnerFASTC (Dec 19, 2016)

sk8rsdad said:


> Some vendors, particularly in the LED architectural market but increasingly more of the low-cost LED providers are coming with RJ45 instead of XLR connectors. I guess they shave a few pennies off the price that way.



I have no problem with the RJ45 where it's not going to be changed much or at all - like architectural - and I believe in a substantial portion of the high schools where it's set and forgotten for the most part. At under a dollar for an RJ45 patch cord and in the $10-20 range for DMX, more for ethercon I think, not hard to see why. And it use to be there might be a half dozen or dozen DMX cords - now might be hundreds. Also, in the field, I trust most electricians today to be able to make cat5 terminations, less confident of their ability to terminate on a XLR5.

Long ways from 0-10 and cinch jones.


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## Brentgi (Dec 20, 2016)

JD said:


> 1) The Cat line should be the ONLY wire in the conduit.



But can you run more that one cat line in the conduit and still be good?


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## microstar (Dec 20, 2016)

Brentgi said:


> But can you run more that one cat line in the conduit and still be good?


You can run as many as you can stuff in there. I don't think there is a % fill rule as with electrical wiring.Within reason of course.


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## BillConnerFASTC (Dec 20, 2016)

Interesting thread given the time spanned. I have been using cat5 for DMX in the wall, and run above ceilings or through roof structure not in conduit (plenum rated of course). 

Today I've been discussing the basic RJ45 patch cord for daisy chaining LEDs in a high school which is unlikely to change much ever.

Of course the more I think about it, I rarely put DMX in the walls - almost always net and DMX nodes. I think this wraps back to Van's DMX for the last mile theory.


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## RonHebbard (Dec 21, 2016)

VRommel said:


> Hi Jay:
> 
> No, we don't include drop chords of any type in our catalog.
> 
> ...


The "drop chords" you refer to are more than likely drop cords without the "h" in there. 
Possibly you'll edit this for posterity in which case this post could be deleted.
Toodleoo!
Ron Hebbard.


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## BillConnerFASTC (Dec 21, 2016)

RonHebbard said:


> The "drop chords" you refer to are more than likely drop cords without the "h" in there.
> Possibly you'll edit this for posterity in which case this post could be deleted.
> Toodleoo!
> Ron Hebbard.


Kind of amusing we have a Canadian as grammar cop. Eh?


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## RonHebbard (Dec 21, 2016)

BillConnerFASTC said:


> Kind of amusing we have a Canadian as grammar cop. Eh?


Yeah but at least I've been working hard on my spellings on the forum. You've no idea how difficult it is for me to leave the 'u' out of words like color and favorite, etcetera. Sometimes I forget and have to go back and edit a post to 'incorrect' my spelling. Who knows, perhaps "chords" was in reference to something musical or structural and I missed the connection.
Toodleoo!
Ron Hebbard.


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