## Ulli-Settings vs. Delaytime

Scope and XITE Development

Original topic on PlanetZ: https://forums.scopeusers.com/viewtopic.php?t=32813

#### Ulli-Settings vs. Delaytime

Posted: Mon Mar 31, 2014 5:40 am
by roy thinnes
Hi,
lately I switched my Ulli settings and saw all delaytimes being out of sync.
Is there someone who can tell me the correlation between Ulli & DT (or even got a formula? )

#### Re: Ulli-Settings vs. Delaytime

Posted: Mon Mar 31, 2014 6:55 am
by sharc
Nice timing Roy
I'm working on ULLI and sample rate dependent ranges for delays at the moment. If I'm not wrong only delays using host ram should be offset by ULLI setting. Logically this should be a round-trip latency, but I've yet to confirm this.

#### Re: Ulli-Settings vs. Delaytime

Posted: Mon Mar 31, 2014 8:27 am
by roy thinnes

> Logically this should be a round-trip latency

Thanks sharc, I think you placed me on the right track.
1000ms->48000
1ms->48
the Ulli setting w/ exact delay times was 25ms (44.1kHz)
my new Ulli setting is 3ms
25-3=22
22x48=1056
1056x2(round-trip )=2112
I added 2112 to delaytime value
>voilà it's in sync again!
so it's just that easy for all Ulli settings:
make a textfader string with 5 values, for each Ulli setting.
the values are:
2112 for 3ms
2016 for 4ms
1728 for 7ms
1152 for 13ms
0 for 25ms
and add the textfader value to the delay value.

#### Re: Ulli-Settings vs. Delaytime

Posted: Mon Mar 31, 2014 12:54 pm
by sharc
Thanks for sharing Roy. That explains why my test results were getting skewed between the SDK and SFP - Different ULLI settings

#### Re: Ulli-Settings vs. Delaytime

Posted: Mon Mar 31, 2014 9:16 pm
by happycritter

> roy thinnes wrote:

> > Logically this should be a round-trip latency

> Thanks sharc, I think you placed me on the right track.
> 1000ms->48000
> 1ms->48
> the Ulli setting w/ exact delay times was 25ms (44.1kHz)
> my new Ulli setting is 3ms
> 25-3=22
> 22x48=1056
> 1056x2(round-trip )=2112
> I added 2112 to delaytime value
> >voilà it's in sync again!
> so it's just that easy for all Ulli settings:
> make a textfader string with 5 values, for each Ulli setting.
> the values are:
> 2112 for 3ms
> 2016 for 4ms
> 1728 for 7ms
> 1152 for 13ms
> 0 for 25ms
> and add the textfader value to the delay value.

Thanks Roy!
This is very useful information and another wrinkle to development that I hadn't given full consideration. I knew sample delays can introduce significant issues, but thanks to your post I realize the hardware end is by no-means 'hands-free'.