No signal on Optical Inputs

[tonwurm]

Recently I switched from TDM to HDX

I still use my old 192, and two 96 Interfaces (the blue ones).

Now there´s an issue with the digital ins of the 96 Interfaces.
In the hardware setup the first 8 channels are assigned to Analog Inputs,
the channels 9-16 are assigned to Optical (Adat) Input (see attached screenshot).

The Adat signal is present on the input meters (channel 9-16),
but if I select f.e. input 9-10 as an input on a stereo-track in Pro Tools, there´s no signal present.

Strange is: if I select in hardware setup the Optical Inputs on channel 1-8, then there is a signal present, if I select these inputs in Pro Tools.

I know, these old interfaces are officially not supported by Avid, but maybe there´s something else going wrong with my setup.

Any help is very appreciated, thanks in adavance !

[albee1952]

They should work and I suspect its a clocking issue. What exactly is connected to the ADAT input? Try setting the Clock Source to ADAT/Optical. In some cases, improper clocking will give you clicks and pops on the ADAT channels, but in other cases, improper clocking will simply give no signal on the ADAT inputs

Also, exactly how are all your interfaces connected? You list a 192 and a pair of 96 boxes, so to use all 3, only 2 can be daisy-chained with the 3rd unit having its own Digilink cable to the HDX card.

[JFreak]

^ Yes, first thing I wanted to check is cabling.

Because you have already been using these boxes you should know, but still double-check that:
- one 192 digilink goes to first card input
- two 96 boxes (daisy-chained) go to second card input
- three digidesign interfaces have proper loop sync (check cables)

After that I can only hope your ADAT boxes have proper wordclock i/o but if you only test one external box (external to the interface stack) it should not matter how you clock it so long as it locks to a clock. Or, as said, worst case scenario is ADAT box needs to be clock master.

[tonwurm]

thanks for your replies.... will check cables again

[tonwurm]

I found out that the PT settings were corrupted

Now the digital inputs work as they should

[tonwurm]

Originally Posted by JFreak

^ Yes, first thing I wanted to check is cabling.

Because you have already been using these boxes you should know, but still double-check that:
- one 192 digilink goes to first card input
- two 96 boxes (daisy-chained) go to second card input
- three digidesign interfaces have proper loop sync (check cables)

thanks for helping me !

Are you sure this is the right way to connect the 3 interfaces to the HDX card?

I connected the interfaces as follows:

Port 1 of the HDX card is connected to the 192 I/O (primary port) and from there (expansion port) to the first 96 I/O (primary port).

The second 96 I/O is connected to port 2 of the HDX card.

Loopsync goes from the 192 to the second 96, from there to the first 96 and from there back to the 192.

[JFreak]

It does not actually matter, so long as the port on your card only "sees" 32 i/o, as in you can only daisy-chain two boxes per connector. And this also applies to 3rd party boxes, some of which daisy-chain internally like my Apogee Symphony II that is capable of 32 i/o using single digilink cable. Cannot daisy-chain those obviously.

Loop sync also, it is a loop. Start from any box and connect to any box etc. finally come back to first box. Once you have a loop then that's it, but breaking one cable may cause so much trouble it is sometimes easier to replace everything rather than troubleshooting which was the broken one. A real non-issue if your interfaces sit installed in a rack.

[tonwurm]

thanks JFreak !!!

Okay... understand

I´ve changed all the sync cables to new ones ;-)