Max. ramp rate

Discussion in 'C-Touch/HomeGate/SchedulePlus/PICED Software' started by brodsky, Dec 2, 2008.

  1. brodsky

    brodsky

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    Hi,

    I have a new MKII touch screen with logic engine & need to ramp some lights from 0% to 100% over an hour (60min.)

    I have programmed the ramping time to 60 minutes but regardless of my code SetLightingLevel("A1_000", 100%, "60m");, the ramping time is about 17 minutes (simulated it on touch screen). I see that the maximum selectable time on a dimmer button is 17 minutes. Is the code wrong, or is it possible to set the ramp rate higher than 17 minutes?

    Thanks
    Brodsky
     
    brodsky, Dec 2, 2008
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  2. brodsky

    Newman

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    The maximum ramp rate that can be sent over C-Bus is 17 minutes, as you've found out.

    If you want to ramp some lights up at a slower rate, like your 60 minutes, then you could write some logic code to send a SetLightingLevel command every 36 seconds that increases the lighting level by 1% each time. Depending on the type of light source, the steps are most likely small enough to go un-noticed.

    An alternative would be to send a command to increase the lighting level by 5% every 3 minutes, however in this case it might be prudent to issue the messages with a 17 minute ramp rate which would make the steps as good as imperceptible.
     
    Newman, Dec 2, 2008
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  3. brodsky

    brodsky

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    Hi Newman,

    Could you please elaborate. I wrote code that increased the light level with 2% every 1:12 minutes and it works well except that I have to do that with 32 circuits, thus causing error messages as my logic is too much or being executed too slowly.

    Trying the other way, I wrote commands to increase the light level in increments of 28% over 17 minutes. This proves not to work as it seems as if the ramp rate is relevant to a 0%-100% span only (regardless of the code), therefore you only get pro-rata of the ramp rate if the "ramp to" level is less than 100% (e.g testing it gave me only 8.5 minutes ramp rate to 50% and 4.25 minutes to 25% even if the logic says it is 17 minutes.)

    Do you have any suggestions, please?

    Regards
    Brodsky
     
    brodsky, Jan 6, 2009
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  4. brodsky

    NickD Moderator

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    As you have found out, a C-Bus "Ramp Rate" is always the time it takes to ramp from 0% to 100%.. ie the *rate* is constant.

    The reason Newman suggested using the 17 minute ramp rate for the 5% change is so that the level doesn't change from, say, 15% to 20% instantaneously... instead it will do it over 51 seconds. Internal to the dimmer this will be a change of 1 step every 12.75 seconds... which will probably be unnoticeable.

    I'm surprised that the logic to do this for 32 groups would generate too much code or run out of processing time... what platform is it on? Can you post your code for one of the groups?

    Nick
     
    NickD, Jan 6, 2009
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