DMX Output Frequency

44Hz is the maximum DMX512 can handle, because a full packet of all 512channels takes about 23ms to be send so this is the maximum speed.

Wondering what advantage you see when rising the rate above 29Hz?

OK, this not the answer to your question, just curious

Thanks Mark, I am aware of the max Refresh Rate capable on Current Ansi DMX 512-A with a full line...

I am not asking for higher than 44hz, just 44hz as I believe it is one of the items in the standards of the current 2008 Ansi DMX512-A.

Anyway.. On High speed playback from a highspeed camera we are seeing color stepping on LED's in a Hue/Sat chase/effect that is directly associated with the DMX Refresh Rate and we know that because we have done tests at different RR's within the range that the H4 can output. We stopped seeing a difference from 30hz to 44hz, which prompted me to put a Swisson on the H4 and that is where I found out that the max RR of the H4 is 29hz even though the DP setting are at 44hz.

JB

Hi Jeff,

I will need to double check this but I am pretty sure you are running up against a limitation of the built-in hardware widgets.

You will see that when using a Hog 4, FB4, RH4, or DP8000 that the art-net output goes all the way up to 44hz.

The physical dmx outputs on the built-in 4 port widgets (RH and FB) only go up to 29h and the physical dmx outputs on built-in 8 port widget (DP8000 and Hog 4) only go up to around 37hz.

It is possible that these physical limitations are not actually limitations of the nuts and bolts of the widgets but actually just limitations written in the widget firmware.

I will need to investigate further, but as you pointed out if you have art-net hardware that can convert and output physical dmx at a refresh of 44hz then that should work for all Hog 4 family products.

Great!!!

Thanks for researching this. I just got off the phone with a friend that just tested some other consoles and he found that the nodes were able to output 44hz when the built in raw dmx ports were limited to much slower refresh rates. I hope this is infact the case if using a DP8000, and or sACN/Artnet to node as this might present a solution.

I am chained to the desk right now, so I don't have the time to check a node or even the raw dmx out of a DP8000. If you get a chance, could ya let me know if you find out that the external DMX network devices (DP's/Nodes) in the H4 line can output 44hz, or in a perfect situation a higher refresh rate with less channels on a line?

Thanks Chris

Appreciate the support.

JB

Edit... PS ... If it is possible, for a future firmware update, would you guys consider bringing the widgets up to current DMX512-A standards?

2nd Edit.... I tested the single and 4 x external widgets and they are also limited to 29hz, but I believe that makes sense, since the guts are the same whether internal or external widget, correct?

"Edit... PS ... If it is possible, for a future firmware update, would you guys consider bringing the widgets up to current DMX512-A standards?"

What about them does not meet the current standard?

I guess the ability to send dmx at 44hz. Although the standard might just be within the range of 20-44hz.

JB

Yes, I am working with our firmware and hardware engineers to try and get to the bottom of this.

Any update to this? I just figured it out as well on a Hog 4 using a DMXter to check refresh rate. Seems to top out around 35-36hz for me. I've been increasing refresh rate as well to smooth LED Fades.

Just FYI, it is not only the H4 internal XLR widgets that are limited. There are other Console brands where the limitation is there as well. My workaround was to run Artnet to Nodes and in which case I was able to get a solid 44hz. I also read somewhere, that even though a full line (Completely filled universe) is only capable of 44hz because of packet length, that DMX refresh rate over artnet can be pushed faster than 44hz by using just a fraction of a universe (Like patching 256 channels instead of 512) which in theory might allow certain enabled artnet nodes to speed up the refresh rate (88hz and so on), but I haven't tried confirming that.

JB

JB some console like MA Lightcommander or AVOs are doing this also on the DMX out.
This often causes problems because some fixtures use the 512 packets for timing and get confused when the Startbyte comes to early