DMX cables

[Gerry]

Just bought some, described as, "QTX Light-DMX Professional Lighting cable" 3 pin XLR cables.

Wiring is connected so pin 2 (Data-) is Red and Pin 3 (Data+) White. Isn't it conventional to have them connected the other way around?

I know in practice it doesn't matter as long as the M and F ends are connected the same.

At the F end Ground is, correctly, connected to Pin 1 but also to the shell.

I thought I read somewhere that the shell should not be connected to Pin 1/ Ground.

Cheers

Gerry

[timsabre]

Just bought some, described as, "QTX Light-DMX Professional Lighting cable" 3 pin XLR cables.

Wiring is connected so pin 2 (Data-) is Red and Pin 3 (Data+) White. Isn't it conventional to have them connected the other way around?

I know in practice it doesn't matter as long as the M and F ends are connected the same.

At the F end Ground is, correctly, connected to Pin 1 but also to the shell.

I thought I read somewhere that the shell should not be connected to Pin 1/ Ground.

Cheers

Gerry

 

I would say that's the standard colour code for audio, if there is such a thing.

In my opinion the shell should not be connected to pin 1 to avoid earthing weirdnesses.

[Shez]

Shell should never be connected to any pin. A lot of trouble that way lies.

[sandall]

The only way to get consistent core colouring is to buy a reel of cable & make up your own leads. A lot of Chinese made-up cables have Pin-1 connected to one or both shells - that's what side-cutters were invented for. This is also a good moment to check that both XLRs are actually wired the same way round, bearing in mind that they probably weren't soldered by the same person!

[Gerry]

Thanks all for confirming my suspicions.

I shall email the supplier to inform them that the QTX branded DMX cables, that they sell, do not comply, in particular the Ground to shell connection, with the recommended standards.

As I live in Spain it is a bit of a hassle to send them back to the supplier in the UK. Far easier to inspect each one and a quick snip or two with side cutters should sort them out. I'll probably swap the Red and White wires around so they match all my other DMC leads, most of which I made up myself.

I was feeling lazy and decided to buy some pre made leads. :(

Cheers

Gerry

[sunray]

Thanks all for confirming my suspicions.I shall email the supplier to inform them that the QTX branded DMX cables, that they sell, do not comply, in particular the Ground to shell connection, with the recommended standards.<br />As I live in Spain it is a bit of a hassle to send them back to the supplier in the UK. Far easier to inspect each one and a quick snip or two with side cutters should sort them out. I'll probably swap the Red and White wires around so they match all my other DMC leads, most of which I made up myself.<br />I was feeling lazy and decided to buy some pre made leads. Gerry

I wouldn't bother rewiring them, My main use is sound and have cables with wildly varying colour schemes from various sources. I even have a 12way multicore with pin2 red/pin3 blue for 8 lines  and pin2 blue/pin3 red for the 4 returns. Just check they are the same both ends and live with it after isolating the shells.

[Brian]

I shall email the supplier to inform them that the QTX branded DMX cables, that they sell, do not comply, in particular the Ground to shell connection, with the recommended standards.

 

Wasn't there a post in the last year or so where someone had bought some DMX cables from a major UK supplier and the same thing (pin 1 to shell) had happened?

[bruce]

 

Wasn't there a post in the last year or so where someone had bought some DMX cables from a major UK supplier and the same thing (pin 1 to shell) had happened?

 

 

that would be this one http://www.blue-room.org.uk/index.php?showtopic=69893

[sandall]

. I even have a 12way multicore with pin2 red/pin3 blue for 8 lines and pin2 blue/pin3 red for the 4 returns. Just check they are the same both ends and live with it after isolating the shells.

Me too - I only noticed when making up adaptors with the spare tails left after butchering one of these multicores for an install.

[bruce]

Fortunately, electrons are colour-blind....

[Gerry]

Agree Electrons are colour blind but I find it convenient to have all my cables following the same convention.

If I need to replace a connector, or chop up a long lead into shorter ones, I don't have to dismantle the other end connector to see which the convention was used.

Cheers

Gerry

[sunray]

Agree Electrons are colour blind but I find it convenient to have all my cables following the same convention.If I need to replace a connector, or chop up a long lead into shorter ones, I don't have to dismantle the other end connector to see which the convention was used. Gerry

Then what happens when you run out of ideal colours in the plethora of combinations out there?

 

I always have both ends open when making cables and of course test during manufacturer and after final assembly.

 

. I even have a 12way multicore with pin2 red/pin3 blue for 8 lines  and pin2 blue/pin3 red for the 4 returns. Just check they are the same both ends and live with it after isolating the shells.

Me too - I only noticed when making up adaptors with the spare tails left after butchering one of these multicores for an install.

Touché. I used a stage snake for an install and chopped 2metres off the 'mixer end', the chopped cable was terminated into a patch panel and found the variation during testing. Most of the 'ends' were then used for patch leads.

[david.elsbury]

It really doesn’t matter.