Wireless DMX HELP!!

[cvhstech]

Hello,

Has anyone, or does anyone have an opinion on the Made in China Wireless DMX Sticks? Specifically the ones you find on amazon? How reliable are these? And for a high school would you recommend them?

Thanks!

 

[LightingGuy89]

I've used the Blizzard Lighting wiCICLE and had some great success.. I've even wired them to batteries with some voltage transformers and had a fully wireless, DMX controlled relay for some practical lights that fly and track on stage.

Amazon.com: Blizzard Lighting wiCICLEs | 2.4 GHz Wireless DMX Interface (wiCICLE Skywire Reciever): MP3 Players & Accessories


-B

 

[microstar]

I've had great success with the Sirs-e anyDMX units. You can buy them on the Sirs-e eBay store much cheaper than their website. Made in China but waranteed by Sirs-e in Texas.

 

[MiltonDavis]

It may work for your application. Always remember: you get what you pay for...

 

[Galen]

Are these functionally the same as using an ethernet to dmx adapter and a wireless router?

Sent from my KFSOWI using Tapatalk

 

[bishopthomas]

I would never use a wireless DMX device that did not do FHSS. If you're stuck on one channel there is much more opportunity to get stepped on. I have a pair of City Theatrical Show Babies and a set of W-DMX Micro units. Neither system has failed me once. They may cost a little more than the Chinese options but when my entire show relies on it I'm not worried about a couple hundred bucks.

 

[bishopthomas]

Are these functionally the same as using an ethernet to dmx adapter and a wireless router?

No. Different protocol.

 

[TuckerD]

No. Different protocol.

Actually I think the answer is yes. Functionally these are the same. You are transmitting DMX signal wirelessly from one location to another. However there are some very significant differences between the two implementations, form factor being a major one that comes to mind.

I'm not sure that @Galen has the right idea about the DMX over wifi implementation though. A DMX to RJ-45 connector (like the one pictured in the link at the bottom) could not be plugged into any old wifi "router" and used to sent DMX to a wifi receiver. For that you need to move up into another protocol like ACN or ETC Net 3 (Which is based on ACN). However, I have never set up an ACN network before though so I'm not exactly sure how that would work.

https://eventhorizon-srv.com/ecomme...oduct_images/event_horizon/RJ45-MX-CAT5-1.jpg

EDIT: Corrected link

 

[Jay Ashworth]

Correct: that is a Layer 0 adapter: it connects one type of copper wire to another; no protocol handling.

Just cause it's 8p8c modular (<pedant>RJ-45 is a *very specific*, and almost never seen, analog telephone interface using such connectors, specified by AT&T in Part 68</pedant>), doesn't mean it's Ethernet.

 

[Jay Ashworth]

And, for the record, I'm pretty sure you want a transformer adapter to run DMX over Cat5/6; the characteristic impedance will be different, the DC resistance will be higher, and the interconductor capacitance will probably be higher too; at DMX rates, this stuff starts to matter.

And yes, Ethernet is much faster, *but that's the cabling it's line drivers and receivers are matched to*.

 

[TuckerD]

Jay, I agree with you 100%. To clarify my post, I was not suggesting that such an adapter be built. I don't think it's a good idea. I really like to go by the books and I am not really a fan of the three pin DMX either.

 

[Jay Ashworth]

Well, FWIW, you *can* build 'real' DMX cable out of A3M connectors; there is a slight bump in the impedance, but nothing like using the wrong cable; I know someone who has 3-pin cables that are properly constructed.

It's just that you run the *risk* of using the wrong wire.

If you want to be covered, bring adapters.

 

[RedGreenBlue132]

A $50 DMX cable is always going to be more reliable than even a $650 wireless system. The most reliable form of wireless DMX probably would be ArtNet over WiFi. Unless you don't have to worry about lag time or interference. If had shows ruined by regular wireless dmx, I was using ADJ Wiflex and lost control of my lights when interference from either the 6 wireless mics or WiFi cause it to stop working.

 

[TuckerD]

Since we are talking about DMX cables.

My recommendation is to build your own. You can usually save a few bucks and depending on your use you can use stranded cat 5 cable.

 

[derekleffew]

And, for the record, I'm pretty sure you want a transformer adapter to run DMX over Cat5/6; the characteristic impedance will be different, the DC resistance will be higher, and the interconductor capacitance will probably be higher too; at DMX rates, this stuff starts to matter. ...

No transformer required, see the PLASA TSP document.


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[Jay Ashworth]

I saw it..., but I'm not sure I'm buying it yet. ;-)

Sent from my SPH-L720

 

[microstar]

Installations run straight (non-network) DMX over Cat5e all the time. See the book "Practical DMX" by Nick Mobsby, http://www.pathwayconnect.com/content/view/91/26/ from the Pathway website, and others. It is often not shielded due to the twisted pairs. RJ45 patch panels are often used as routing devices.

 

[Jay Ashworth]

It is always not shielded, cause ethernet cable isn't. STP has a markedly different impedance and capacitance. IIRC.

Sent from my SPH-L720

 

[Jay Ashworth]

And, also by way if rebuttal, installations run DMX over 3 pin Audio cable all the time, too. That doesn't necessarily mean that they are operating within the actual specification.

I'm by no means an EE, but everybody who talks about this, including PLASA, seems to be hand waving the actual numbers.

Sent from my SPH-L720

 

[TuckerD]

There is no official document published by PLASA supporting the use of 3 pin XLR cables. Does it happen? Yes, of course. Personally I don't think it should. People should either use the standards or come together and push for a change. I would not support a change in the standard because I think that separating these cables avoids confusion. I have worked on a number of setups that have faults because of the use of three pin cable as DMX cable. Most of the time the people who set these networks up don't realize that as the length of your network increases so does your chance of faults. They usually only by one length of cable, too long, because "What's the problem, it's the same cable that you use for a mic".

ANSI E1.11 Section 7.1.1 through 7.1.2 states the following:

7.1.1 Required connector
Equipment in this category shall use 5-pin XLR connectors with the physical pinout of the 5-pin XLR in
accordance with Table 3.

Table 3 -

[Omitted in this quote]

7.1.2 Concession for use of an alternate connector (NCC DMX512-A)

A concession to use an alternate connector is available only when it is physically impossible to mount a 5-
pin XLR connector on the product. In such cases all the following additional requirements shall be met :

1) The alternate connector shall not be any type of XLR connector.
2) The alternate connector shall not be any type of IEC 60603-7 8-position modular connector
except as allowed in clause 7.3.
3) Provided that all other requirements of this Standard are met, in addition to the declaration in
the equipment manual, the alternate connector shall be marked as NCC DMX512-A (Not
Connector Compatible). If such a marking is not physically possible at the connector, an
appropriate marking shall be made elsewhere on the equipment. The pin numbering on the
alternate connector should match numbering for the standard 5-Pin XLR connector.
4) The manufacturer shall make available an adapter with the appropriate connections to a
standard 5-pin XLR connector for all DMX512 ports included in the alternate connector.
5) The Enhanced Functionality, if applicable, and ground/isolation declarations shall continue to
be declared for each DMX512 port.

This means that the three pin connector can not be used on a cable that claims to be complaint to ANSI E1.11 or E1.27 for the transport of DMX signal.

As far as the actual cable that the connectors are attached you should refer to ANSI E1.27 - 1 and ANSI E1.27 - 2. I will summarize them here but all documents mentioned in this post are available for free here. The first of the two standards covers cable for use in portable applications. "Portable" is typically taken to mean "on the road" where the cable will me moved, coiled, bent, or plugged and unplugged frequently. Section 4.3 says:

Portable DMX512 cables shall use twisted pair conductors. Conductors shall be of stranded construction ... Shielding shall be on individual pairs or overall shielding of pairs, or both. The portable cable itself shall be flexible and rugged enough for the repeated coiling and uncoiling to which it will be subjected.

ANSI E1.27 - 2 covers cable construction standards for permanent installation. The only major difference between this standard and the previous is that the standard for permanent applications allows for the use of cables specified as EIA Category 5 or higher. The change to allow for category 5 or higher cable happened after the PLASA Control Protocols Working Group published a report detailing the testing done to compare Cat 5 cable to the EIA-485 cable specified previously. The report was published in October of 2000. All parts of the report can be found here and the summery of the report can be found here (pdf).

I'm not trying to through the book at someone and criticize them personally for the use of 3 pin XLR but I am trying to clear up what the standards actually say and provide some useful links.

At the end of the day the curtain has to open and that sometimes means you have to cut a corner. Each of the standards mentioned contain a subsection labeled "Compliance" in section 1 which states

Compliance with this Standard is strictly voluntary and the responsibility of the manufacturer. Disclosures and
identification or other claims of compliance do not constitute certification or approval by PLASA.

As a TD, LD, Product Engineer, or Manufacturer you have to decide what the right thing to do is right now. If it's possible to follow the standard you should, but if you need to re-terminate that last DMX cable 30 minutes before the show starts and all you have are 3 pin connectors and it will work, then I would say that you should use the three pin connector.

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For anyone who is looking for supplies to build cables that match these specifications I have been able to source some components from distributors that I trust.

http://www.amazon.com/dp/B0085X62Z6/?tag=controlbooth-20 ($150)

Female 5 pin XLR
Male 5 pin XLR