Using a Studiolive III 24R rack how do I record the stereo mix to a SD card thru UC Control?

Using a Studiolive III 24R rack how do I record the stereo mix to a SD card thru UC Control?

I was thinking you could record your stereo mix straight to the SD without a separate DAW in a live situation.

I do not see anywhere on the iPad app where recording to the SD exists.