@KR
No – the gigaACE card provides a 128×128 96kHz connection with optional redundancy using the second port (https://www.allen-heath.com/media/gigaACE-fitting-note-AP10842.pdf#page=1&zoom=auto,-361,135).
So you can have only have one gigaACE/GX connection per I/O port, though this can be a redundant connection where supported (two examples being dLive to Avantis or connecting to 2x DX Hubs – https://www.allen-heath.com/media/DX-GX-System-Guide-ISS_5.pdf#page=5&zoom=auto,-274,481).
If you need to share audio between the three systems, you would need to add another gigaACE card, or an SLink card to one of the SQ’s and make use of tie-lines.
Hope this helps!
Keith.
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