Hog III DMX Dynamic Refresh Rate?

I'm currently working with a company that makes a DMX recorder that's giving me fits when I try to use it with the Hog III consoles (Hog III and Hog 3PC).

Their engineer seems to think it has to do with the Hog III either not being set at a high enough refresh rate (mine is currently set at 25, which I think is the default and should be sufficient) or because the Hog could be in what he calls a "dynamic DMX mode". I've never seen such a mode anywhere on the system, and can't find anything now. Any idea? I'm definitely seeing drops in the DMX data, especially when I bring up menus and whatnot.

Any help would be greatly appreciated.

Mark Novick
Lighting Designer
Fastlane Productions
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    I imagine what they're talking about with regard to "dynamic DMX" is the fact that the Hog's DMX refresh rate is not constant. The refresh rate set in the DP's menu is the maximum allowable refresh rate, but under sufficient load the refresh rate can and will drop below the set rate. Odds are the DMX recorder is designed under the assumption that consoles will output refreshes at a fixed rate.

    Why don't we output at a fixed rate, you ask? The Hog is designed such that the values in a given refresh are correct for only the instance in time that the frame is generated. As such, we only transmit when we have generated a "fresh" frame of data. Some consoles will retransmit a stale data frame to keep up the appearance that they're refreshing at a fixed rate. We do not do this as it affects the fixtures that are receiving the data. It gives the appearance of a steppy fade/movement and throws off the fixture's rate interpolation algorithms. However, I see how a DMX recorder designed without this in mind could experience issues.

    Is there a way to set parameters on how and when the recorded decides that DMX has stopped being transmitted?

    Jason Potterf
    HES/FPS R&D
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  • 0
    I imagine what they're talking about with regard to "dynamic DMX" is the fact that the Hog's DMX refresh rate is not constant. The refresh rate set in the DP's menu is the maximum allowable refresh rate, but under sufficient load the refresh rate can and will drop below the set rate. Odds are the DMX recorder is designed under the assumption that consoles will output refreshes at a fixed rate.

    Why don't we output at a fixed rate, you ask? The Hog is designed such that the values in a given refresh are correct for only the instance in time that the frame is generated. As such, we only transmit when we have generated a "fresh" frame of data. Some consoles will retransmit a stale data frame to keep up the appearance that they're refreshing at a fixed rate. We do not do this as it affects the fixtures that are receiving the data. It gives the appearance of a steppy fade/movement and throws off the fixture's rate interpolation algorithms. However, I see how a DMX recorder designed without this in mind could experience issues.

    Is there a way to set parameters on how and when the recorded decides that DMX has stopped being transmitted?

    Jason Potterf
    HES/FPS R&D
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