F16v4 with DMX

[xdandev91x]

Thank you to all last year who got me through my first show!

Looking to scale up this year and redesign a few things. I've started looking into DMX and all the cool things which can be done with it. I am keen on adding moving heads, fog, snow and bubble machines eventually.

My understanding of DMX use in reference to the Falcon boards:
- DMX devices are daisy chained via DMX in and DMX out ports on each accessory. Terminate the end of the chain using a Terminator.
- I understand that there are multiple DMX cable ends (3 pin xlr, 5 pin xlr, rj45). I don't understand how the different standards interact or their implications (see below).
- DMX devices use 'channel's' to delineate and control functions (e.g. Channel 1 is pan, channel 2 to tilt, channel 3 is slow pan etc.)
- Different DMX devices may have different amounts of channels required, depending upon its functions.
- I have a maximum of 512 channels on one daisy chain, between 32 devices.
- Forum posts recommend halving to 16 devices to avoid issues.
- Don't use microphone cables even if it technically works for small distances.

My questions:
- How do the different standards of DMX work together?
- Can I use 3 pin, 5 pin or Rj45 port DMX accessories together on the Falcon DMX output? If yes, does this mean I just need to buy converters (or DIY an RJ45 cable to XLR end) as the cable ends go to different DMX device standards (i.e. Falcon (rj45) to 3pin xlr moving head to 5pin xlr smoke machine to 5pin xlr terminator)
- Some DMX devices explicitly mention DMX512 compatibility. Are these the only DMX devices I can use with Falcon boards or does this literally imply it simply has an RJ45 input in / out?
- Are there any other gotchas I should know before I buy these DMX devices?

Thanks peeps!

 

[Skymaster]

Thank you to all last year who got me through my first show!

Looking to scale up this year and redesign a few things. I've started looking into DMX and all the cool things which can be done with it. I am keen on adding moving heads, fog, snow and bubble machines eventually.

My understanding of DMX use in reference to the Falcon boards:
- DMX devices are daisy chained via DMX in and DMX out ports on each accessory. Terminate the end of the chain using a Terminator.

Correct

- I understand that there are multiple DMX cable ends (3 pin xlr, 5 pin xlr, rj45). I don't understand how the different standards interact or their implications (see below).

3 pin XLR is expressly prohibited by the DMX standard, but seems to be used commonly. The pinout of a 5 pin connector is 1- Ground, 2- Negative Data, 3- Positive Data. Three pin XLRs typically follow this as well.
The 8p8c connector is wired with pins 1 & 2 positive and negative data, and pins 7 & 8 ground.
You can just wire from one connector to another keeping the polarity consistent.

- DMX devices use 'channel's' to delineate and control functions (e.g. Channel 1 is pan, channel 2 to tilt, channel 3 is slow pan etc.)
- Different DMX devices may have different amounts of channels required, depending upon its functions.
- I have a maximum of 512 channels on one daisy chain, between 32 devices.
- Don't use microphone cables even if it technically works for small distances.

All correct.
On the last point, it should be 110-120 ohm data cable, 2 core twisted and shielded. CAT5 is also suitable, with a slightly lower impedence (100 ohm) so reflections are minimised.
The termination resistor should also match this, and be p[laced across the positive and negative data pair.

- Forum posts recommend halving to 16 devices to avoid issues.

This depends on cables, devices, etc.
Correct. It should be 110-120 ohm data cable, 2 core twisted and shielded. CAT5 is also suitable, with a slightly lower impedence (100 ohm) so reflections are minimised.
The termination resistor should also match this, and be p[laced across the positive and negative data pair.

My questions:
- How do the different standards of DMX work together?
- Can I use 3 pin, 5 pin or Rj45 port DMX accessories together on the Falcon DMX output? If yes, does this mean I just need to buy converters (or DIY an RJ45 cable to XLR end) as the cable ends go to different DMX device standards (i.e. Falcon (rj45) to 3pin xlr moving head to 5pin xlr smoke machine to 5pin xlr terminator)

Yes. Just wire the cables. There are no differences electrically, just the mechanical connector.

- Some DMX devices explicitly mention DMX512 compatibility. Are these the only DMX devices I can use with Falcon boards or does this literally imply it simply has an RJ45 input in / out?

USITT DMX512/1990 is the name of the the standard with a revision being DMX512a in 2008. This relates to the protocol and signalling. All DMX gear "should" operate correctly. The 8p8c connector was added in the 2008 revision of the DMX standard to be a suitable connector.
It complicates things on a Falcon as there are 3 different uses for 8p8c connectors, being the Ethernet, DMX and Smart Receiver ports, none of which are protocol or electrically compatible.

- Are there any other gotchas I should know before I buy these DMX devices?

Thanks peeps!

 

[merryoncherry]

As a person who likes to "wing it", I would add the following.

DMX is essentially a broadcast, and each device has a channel selector, so you can plug things on the chain in any order. (You probably knew that, but just making sure... It's great because you can rearrange cables at the last minute and everything still works.)

DMX data rate is very low at 250kbit/s, and the signaling is pretty robust electrically by design, but on the other hand it is an old spec designed to be run in an old way (being 40 years old) and with modern stuff it can be mostly implemented quite cheaply and often is, with a few cents worth of stuff... the timing is usually replicated well but some of the other electrical characteristics may not be, often for the better but occasionally for the worse.

Long way of saying, in practice, you shouldn't have any trouble but you might. I brought all my DMX stuff (20+ PARs) to the same cafetorium once and was very glad I had an isolator/amplifier/splitter device in hand, or it would not have worked. Another thing to keep in mind is you can just get another DMX controller (doesn't have to be a full F16 or anything) and split your network up.

Having a test device handy has saved me a lot of time. I think F-test does this, but I don't have one. I do have a little DMX board with 30 LEDs on it and both kinds of connectors, that has been really useful.

Lastly, about bubbles, I was told to use the remote on the machine rather than DMX control, and I am glad I followed that advice... otherwise a lot of bubbles would have been wasted when nobody was around, and when people were around there sometimes wouldn't have been bubbles.

 

[Skymaster]

Having a test device handy has saved me a lot of time. I think F-test does this, but I don't have one.

The F-Test will both read DMX and generate it.

 

[xdandev91x]

Correct

3 pin XLR is expressly prohibited by the DMX standard, but seems to be used commonly. The pinout of a 5 pin connector is 1- Ground, 2- Negative Data, 3- Positive Data. Three pin XLRs typically follow this as well.
The 8p8c connector is wired with pins 1 & 2 positive and negative data, and pins 7 & 8 ground.
You can just wire from one connector to another keeping the polarity consistent.


All correct.
On the last point, it should be 110-120 ohm data cable, 2 core twisted and shielded. CAT5 is also suitable, with a slightly lower impedence (100 ohm) so reflections are minimised.
The termination resistor should also match this, and be p[laced across the positive and negative data pair.


This depends on cables, devices, etc.
Correct. It should be 110-120 ohm data cable, 2 core twisted and shielded. CAT5 is also suitable, with a slightly lower impedence (100 ohm) so reflections are minimised.
The termination resistor should also match this, and be p[laced across the positive and negative data pair.


Yes. Just wire the cables. There are no differences electrically, just the mechanical connector.


USITT DMX512/1990 is the name of the the standard with a revision being DMX512a in 2008. This relates to the protocol and signalling. All DMX gear "should" operate correctly. The 8p8c connector was added in the 2008 revision of the DMX standard to be a suitable connector.
It complicates things on a Falcon as there are 3 different uses for 8p8c connectors, being the Ethernet, DMX and Smart Receiver ports, none of which are protocol or electrically compatible.

Thank you heaps for the prompt response and fantastic detail throughout. Genuinely appreciated. I guess this weekend I'll be much poorer as I commit to a few DMX device purchases and start testing now!

 

[xdandev91x]

As a person who likes to "wing it", I would add the following.

DMX is essentially a broadcast, and each device has a channel selector, so you can plug things on the chain in any order. (You probably knew that, but just making sure... It's great because you can rearrange cables at the last minute and everything still works.)

DMX data rate is very low at 250kbit/s, and the signaling is pretty robust electrically by design, but on the other hand it is an old spec designed to be run in an old way (being 40 years old) and with modern stuff it can be mostly implemented quite cheaply and often is, with a few cents worth of stuff... the timing is usually replicated well but some of the other electrical characteristics may not be, often for the better but occasionally for the worse.

Long way of saying, in practice, you shouldn't have any trouble but you might. I brought all my DMX stuff (20+ PARs) to the same cafetorium once and was very glad I had an isolator/amplifier/splitter device in hand, or it would not have worked. Another thing to keep in mind is you can just get another DMX controller (doesn't have to be a full F16 or anything) and split your network up.

Having a test device handy has saved me a lot of time. I think F-test does this, but I don't have one. I do have a little DMX board with 30 LEDs on it and both kinds of connectors, that has been really useful.

Lastly, about bubbles, I was told to use the remote on the machine rather than DMX control, and I am glad I followed that advice... otherwise a lot of bubbles would have been wasted when nobody was around, and when people were around there sometimes wouldn't have been bubbles.

Thank you the detail here, you've given me a few extra things to consider. While I'm usually the wing it type also, I have an opportunity to get quite a few DMX devices at discount if I bulk buy so I figured I'd better do my research first!

I'll take your advice and get a few amplifiers just in case. My setup is going to be quite minimal. I can't imagine anything more than 5 or 6 devices Max but never a bad idea to have them on hand.

I didn't think of splitting the DMX side away from the Falcon board, for no reason other than convenience and familiarity. I presume I'd simply connect to the DMX controller in Xlights in a similar fashion to how I'm connecting to the Falcon board now. Do you recommend any simple or specific DMX controller?

Your advice regarding the bubbles / fog is a good point. I definitely had a few lulls where I wouldn't have wanted to waste materials. Regardless, still keen on having DMX available just in case.

 

[merryoncherry]

I'll take your advice and get a few amplifiers just in case. My setup is going to be quite minimal. I can't imagine anything more than 5 or 6 devices Max but never a bad idea to have them on hand.

In that case you'll be fine. But the nice thing about the splitter (I got a cheap one - https://www.amazon.com/dp/B00FS5W5E6) is that you can put it in the middle of the setup and run cables a few directions... might pay for itself on just having shorter cables / running in more convenient places.

I didn't think of splitting the DMX side away from the Falcon board, for no reason other than convenience and familiarity. I presume I'd simply connect to the DMX controller in Xlights in a similar fashion to how I'm connecting to the Falcon board now. Do you recommend any simple or specific DMX controller?

While I know one or two use Enttec or compatible devices, I've not done this. They're sort of pricey for what you get, and hey why not get a full pixel controller for a few bucks more and split the pixel part of the show up too, more room to expand .