digilink cable length question

[mightyduck]

Hi,

I have a Thunderbolt HD Native interface and an Omni HD that is attached to it via Digilink primary port [12 foot cable, I believe].

The Omni also has a Digilink Expansion Port, to which I would like to attach one of my old 192 I/Os. I may want to daisy chain some others as well, if possible.

What is the approved Digilink cable length for attaching an Expansion Interface as described above?

Based on what little I have been able to find on this issue, the maximum cable length between interfaces seems to be 18", but what I read was from 2007 so I am asking here in the hopes that someone knows for sure.

Thanks,

MD

[BScout]

A) You cannot daisy chain more than one interface. Primary to expansion and that's it.

B) Expansion to primary (first and only allowable chain) needs to be the shortest at 18".

In fact, there are length limits for card to primary if you want to go to higher sampling rates. Something to keep in mind

[mightyduck]

Originally Posted by BScout

A) You cannot daisy chain more than one interface. Primary to expansion and that's it.

B) Expansion to primary (first and only allowable chain) needs to be the shortest at 18".

In fact, there are length limits for card to primary if you want to go to higher sampling rates. Something to keep in mind

Thanks, man.

Most of the stuff I'm working on was done at 192kHz, so what is the current length limit that is "supported" for that?

I have a 12-foot cable going from the Thunderbolt interface to the Omni, and it seems to be playing the 192kHz sessions o.k., so I assume that's within the supported length limits for card to primary at high sample rates.

But if I am reading you right, it needs to be 18" max after the first interface, for any sample rate. Right? Or can one get away with longer lengths at lower sample rates?

Thanks again,

MD

[BScout]

Originally Posted by mightyduck

Thanks, man.

Most of the stuff I'm working on was done at 192kHz, so what is the current length limit that is "supported" for that?

As you can see (from the HDX manual), 50ft digilink cable

But if I am reading you right, it needs to be 18" max after the first interface, for any sample rate. Right?

yes. Expanded on the expansion port needs to use the 18" cable

[mightyduck]

Originally Posted by BScout

As you can see (from the HDX manual), 50ft digilink cable




yes. Expanded on the expansion port needs to use the 18" cable

Thanks.

Can you tell me where the 18" cable requirement is in the documentation. I believe you, I just need to be able to show it to the vendor.

Thanks again,

MD

[BScout]

Originally Posted by mightyduck

Thanks.

Can you tell me where the 18" cable requirement is in the documentation. I believe you, I just need to be able to show it to the vendor.

Thanks again,

MD

Page 7 of the expanded systems manual. Didn't change between HD systems and HDX because the ports and communication is the same (why you can still use the 192)

[mightyduck]

Originally Posted by BScout

Page 7 of the expanded systems manual. Didn't change between HD systems and HDX because the ports and communication is the same (why you can still use the 192)

Thanks. I think I saw that when I was searching on the web, but the only issue I had with it was that I don't think they came right out and said that longer lengths are not supported [or what will happen if you use a longer length]. Weird......maybe its as explicit as they want to get for some reason.

What are your thoughts on that? [not trying to nit-pick]


Thanks again,


MD

[BScout]

It would be tedious if they had to tell users what not to do each time they tell them what to do. Follow their approved setups -- there's enough issues that can crop up that screwing up the simple things is a waste of worktime if things don't work right. If you need to use a longer cable, go off of the second HDX port.

There is most likely a "total length issue" since the expanded interface is really just passing through.

[mightyduck]

Originally Posted by BScout

It would be tedious if they had to tell users what not to do each time they tell them what to do. Follow their approved setups -- there's enough issues that can crop up that screwing up the simple things is a waste of worktime if things don't work right. If you need to use a longer cable, go off of the second HDX port.

There is most likely a "total length issue" since the expanded interface is really just passing through.

Well, I don’t think it would be tedious, and even if it were, so what? I have a case for tech-support on this issue and they say that they use the 1.5 m cables for 1902khz to ensure data integrity. But they won’t come out and say it’s required. There’s obviously a totall length issue. But what’s the Threshold issue? Is it jittery or actual data loss? No, I think there should be detailed and specific published information on these types of Issues.

MD