DP refresh rate

sicklouiesicklouie Registered User
I've re-installed a Hog 3 on a local Christmas show in it's third year. The show file is a continuation from the first year with some fixture changes and additional programming. It seems that all timed functions of the cues run much faster than last year. There are some new fixture types in the rig now that don't have very good dimmer curves but the faster rate appears global (including desk channels). One thought that I had was perhaps the rate was actually slow in the older software and now everything is up to speed. Is there documentation to support what I'm seeing onstage? Does the refresh rate of the DP impact timing functions? I noticed that the DP on this desk is set at 25 Mhz. What is the normal refresh rate?

SWV 2.2.2 installed.


  • Marty PostmaMarty Postma Registered User
    edited November 2007
    The normal refresh rate is between 25-30. I wouldn't think that to be the problem here though.

    Have you changed any of the components that the DMX passes through? Opto-splitters, etc.

    Are you running off of SMPTE? Is the SMPTE coming off a device that uses a hard-drive rather than tape?

    I would say that a more likely culprit would be SMPTE coming off a device that uses a hard-drive. When changes are made to the SMPTE code it is never a simple "add 2 seconds and 10 frames here" kind of thing. I've done entiire shows where all the SMPTE needed to be "re-learned" and adjusted because changes near the beginning of the code. My suspicion is that the hard-drives' seek and retrieve time is never consistent and this can screw things up down the line in an exponential manner once a change is made to the code. Once adjusted though things played back as they should.
  • sicklouiesicklouie Registered User
    edited November 2007
    Thanks for the reply Marty.

    No time code involved in this show. Just an operator pushing the big Go button. I experimented with changing the path on the intensity of the automated fixtures with what I though were marginal results. The Elation Design Spot 575 and Design Wash 250 have a pretty bad dimming curve. The show is basically one list. I figured that by changing the path on the intensity perimeter at the beginning of the list, that would track forward through the complete list. During programming I never changed path. That was not the case. Apparently anytime I did a "pig active" on cues to be copied - that includes path and put a default path hard command in that cue. I next tried changing the default intensity path on the fixture profile using patch, then editing each fixture. Unknown if that had the intended results as it doesn't change the label in the intensity - path cell of a cue loaded in blind.

    I'll probably change the refresh on the DP to 30 Mhz to see if there's any change in fade times. I don't think there's any negatives to doing that. I've only run into one fixture type that doesn't like the faster refresh rate - Coemar iSpot 575 MB refuse to run on a DP at that rate.
  • CRBatchelorCRBatchelor Registered User
    edited December 2007
    I am stuck with the dreaded iSpot 575 MB fixtures! Did you figure out how to get around this problem?
  • sicklouiesicklouie Registered User
    edited December 2007

    Try changing the refresh rate on your DP to 20Mhz. We did that a few years back and if I remember correctly - that slowed the data down enough to allow the iSpot 575 MB to function properly. It shouldn't have too much of a negative impact on the rest of your fixtures.
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