As firewire seems to work (Audio Device should be PreSonus FireStudio), I would check if there is some signal (audio level) on tracks 1 to 16 in Capture and where that goes. The SL has a 1:1 routing, which means that track 1 is directed to channel 1 on your board - and so on. It's the same for recording. Channel 1 is recorded on track 1 in Capture. There is helpful information about all this in the manuals. For the moment just try to find out where the signals go/where they get lost.