Connect iConnectivity Interfaces via USB!
Do you have an iConnectivity interface with a USB MIDI Hosting jack (mio4, mio10, iConnectMIDI4+, iConnectAUDIO4+)?
Did you know you can connect a second iConnectivity interface to it? The Host jack has up to eight 16-channel MIDI ports (ten on the mio10), and you can route any or all of them to a second interface and access all its MIDI connections.
So, for example, if you have an iConnectAUDIO4+ and its single 5-pin MIDI DIN pair isn't enough, pick up a mio2 and you'll have three pairs.
The connection is simple: second interface's Device jack to Host jack (instead of a computer device).
Why not just connect both interfaces directly to a computer, where all their ins and outs are seen automatically? Normally you would, and you can also aggregate audio interfaces this way for more audio I/O pairs. What we're talking about is useful if you're on stage without a computer, or maybe if you're only using an iPad (which only has a single port).
It's also useful if you have the "piggyback" interface's second Device jack connected to a third computer device. Your system now has a whole lot of interconected MIDI highway.
One final reminder: the USB Host Port carries MIDI, not audio.