What is the procedure for connecting up the DX168 or DX164 using redundant connections to a CDM32?
Is there a way to do it without using up the slot on the CDM32 with either the DX HUB or DX LINK expansion boxes?
I couldn’t find anything on the website regarding this specifically.
Thanks!
Redundant connection only works with additional cards or the S series…
that’s one reason why the C series is cheaper than S class
Thanks, Steffen. I’m aware of that difference, but thought that there might be a way to get redundancy using the HUB or LINK devices without adding a card to the slot.
Mr.X, think about it: Even IF you can use a DX-Hub for redundancy, the connection to the mix rack via GigaACE would be non-redundant. The DX-Link card will allow for DX redundancy, but of course will use up the only expansion slot in the CDM.
The connection from the external hub to the mixrack is not the problem. I’m just looking for redundancy on the external preamps which would be at some distance from the mixrack. The Dx link or hub would be in the same location as the CDM.
So what you’re saying is the only way is with the card in the slot, yeah?
Yes. AFAIK the hub does not support redundancy.
The DX Hub supports redundancy in a dual hub configuration. In this configuration, Link A and B from a gigaACE card in the MixRack/Surface connect to two separate DX Hubs, thus offering redundant connections to DX Expanders.
See page 6 of the DX guide.
Thanks, Nicola, but there’s no way for redundancy WITHOUT using up the I/O slot in the CDM, correct?
For the DX hub you’d need the GigaACE card, so the slot would be populated one way or the other, yes.
Thank you, Jens.
So, why can’t the existing giga-ACE connection be used to connect to the hub?
(I’m not using a surface, btw)
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Because the on-board gigaACE port is designed as the main link to a dLive Surface. Not for I/O expansion.
Nicola, is the redudandant mode automatically set if you use two hubs on a GigaACE card and just connect the primary DX port to one hub and the secondary to the other? Or will the GigaACE card always expect a hub on the secondary GigaACE link to be a redundant link to the DXs (so no two independent hubs with four to eight DXs each on one GigaACE card possible)? Also, does it matter if you connect the primary DX ports to the hub that’s on the secondary GigaACE link of the card? I’d like to know the “fine print” on those matters 
Hi Jens,
The gigaACE card always works in redundant mode. So to answer your question, if a DX Hub is connected to Link A, Link B can only be connected to a second DX Hub for redundancy purposes.
In such a system, I would suggest connecting all ‘A’ ports from your DX Expanders to DX Hub ‘A’, and all ‘B’ ports from your DX Expanders to DX Hub ‘B’.
Do not connect A and B from a DX Expander to the same DX Hub - that’s not supported.
Since you also mentioned the DX Link option in this thread, this card would give you the choice of either 4x parallel DX ports OR 2x redundant pairs. You choose the mode via a software switch. So with a single DX Link card you can connect 2 DX Expanders with redundant cable. In comparison, the gigaACE + dual DX Hub scenario above allows up to 4.
Thank you, Nicola.
So the GigaACE card cannot act as two independent GigaACE ports? That’s a pity. The secondary port will be useless in most scenarios, especially with C-Class owners (since they can’t get redundancy to the primary surface anyway). Is there a possibility to change that via software/firmware in the future or is this set in the used hardware? More flexibility is ALWAYS welcome.
I had read that if you install a GigaACE card in the CDM rack and one in a C-series surface, you can run a redundant connection between the two.
AFAIK not for the primary surface.
with the FibreACE card it’s possible…
Still not possible. FiberACE card works in the surface only as a converter as it seems. You need to connect the surface’s built-in GigaACE links to the RJ45s on the FiberACE card and set it to “convert”. That still means only non-redundant link to the mix rack.