DiGiCo's Little Blue Box, allows you to connect an SD9, SD11, D-Rack and MADI console (SD8, SD7 or even a D-Series), thus allowing you to share a D-Rack between two or three consoles. The SD9 / MADI switch allows you to select between the SD9 (or SD11), or whatever console is plugged in to the MADI connector to control the D-Rack. The Console RX. Auxiliary output is designed to be the redundant run on an SD8 or SD7. Alternatively, it could be split off to another console with one SD9 (or SD11) using a CAT5 connection and one MADI pair for the SD8, which could then feed off to a recorder or another console.
Once again, the Little Blue Box is powered via USB, with a second USB port acting as a thru.