How to Stagger the starting of Scene Components ?

Hi all, a quick question...

I'm programming a B&W C-touch, and adding some very large scenes that will draw a considerable amount of power. I don't have a relay here to play with, I am working offline then will download all programming to the units on-site. Therefore I need advice on how to do what I need.

All output units are relays (20A 4ch L5504RVF20's) - whilst each GA is fairly small (maybe 10-20A each), some scenes switch on 10 or 20 of those loads. I need to delay / stagger the On Events so that a big scene doesn't switch them all on at once and cause a huge demand spike. But I don't want to "delay' the On Event when using Individual GA controls, I only want to do it for certain (big) scenes.

What is the effect of Ramp Rate when used with Relays? Can I use that to do what I need? Do they switch on at 1%, or at 100%? Does Ramp Rate work with relays?

If Ramp Rate can't do what I need, is there an alternative way? I'd rather not have scenes that trigger other scenes, as I need to keep the future Scene Editing easy for the client.

Perhaps the solution to program the Relays themselves ? I notice that there is a "Turn-On Threshold" in there, which I assume means I can change them so they switch on at 99% instead of the "standard" 0%. By changing that, does it mean I can then use Ramp Rate?
- Only problem I can see is that the Ramp Rates are pretty "course" - I can only choose 4s, 8s, 12s, 20s etc. So if I have 10 scene components then I can't stagger them all and have the scene set within a reasonable period.

Or is there a better way using a combination of both a staggered Turn-On Threshold in the Relays, plus using Ramp Rates in the scenes?

Your guidance, experience and advice would be greatly appreciated. Perhaps there's a "big scenes for dummies" page or a tutorial somewhere?

Thanks very much, John

 

Ramp rate does work with relays and turn on thresholds. Do not as in DO NOT have scenes triggering scenes unless you have zero stress in your life and you need some. Actually scenes triggering scenes is not acutally bad it just becomes more cryptic than it has to be.

As is always the case the more that can be done in base C-Bus the better. In this case you want a robust solution because of the significant loads.

Remember the ramp rate instruction is an instant message on the bus, it is the output unit unit that provides the timing.

So if you have a scene that ramps two groups both over 20s the first group is on a relay that has a 1% turn on threshold and the second has 100 % turn on, when the scene runs the relay with the 1% will turn on almost instantly and the relay with the 100% will switch after the 20s. 50% turn on will give you approx 10s and so on. Hope this helps.

Answered this one as I know the brains trust have a public holiday..

 

Thanks, Phil. It is as I suspected it would be...

The bummer is that I just gotta spend another few hours stuffing around to work out how to do the staggers / threshholds. There are probably 80 x GAs over 20 relays, and they are not "logically grouped". In other words, the loads I need to stagger are not necessarily all on the same relay.

Considering the B&W C-touch has a clock, you'd think it'd be easy to have "delays" in scenes. But I guess that'd need pauses, which means I'd need to use Logic....

LOL - there is some perverse logic in having a day off work to celebrate Labour Day

Cheers, John

 

Adelaide Cup Day actually not that I've ever been to the races.. waste of time and money..

 

I wasn't referring to SA Brain Trust - it was Labour Day in Victoria

 

I was referring to the Brains Trust (our mates in SA) and John was referring to Victoria. I hope I don't sound parochial but does Victoria actually have a brains trust ?

 

And I presume the reverse is the situation in turning relays off. This would explain how my 'Going Out' scene works alright but the 'Welcome Home' scene brings all the relay driven lights on at once.

Will setting the TURN ON thresholds of the output relays to 50% mean that both the turn on and turn off timing would effectively be 1/2 the time set in the scene. If I set it for 12 seconds it will turn on in 6 seconds and turn off in 6 seconds?

 

That's correct. By tweaking the ramp rates for components in a Scene, and the turn-on threshold in the relays, most things can be achieved.

 

Thanks Newman,
The more things I try to do the more I am surprised that it is possible with cbus. Glad I went this track and not x10.