In Pro Tools LE:- Setups Menu > Playback Engine > Other Options > Set Optical Format to S/PDIF > Done > OK. Pro Tools LE will reload. - Setups Menu > I/O Setups > Click on Input Tab > Click on Default button to Reset I/O's > OK. - Setups Menu > Hardware > Sync Mode to Optical.- Create a stereo audio track. File Menu > New Track.- Set inputs of stereo audio track to S/PDIF L - R (Opt).- Record enable stereo audio track. - Press play on external digital device and Pro Tools should get level on the peak meter in the stereo audio track. - Press record and play on the Pro Tools transport and record.******Remember to set sync mode back to Internal after you are done recording in from external digital source. - Setups Menu > Hardware > Sync Mode to Internal.******Make sure that sample rates match between Pro Tools and external digital source. - Setups Menu > Hardware > Check Sample Rate of Pro Tools session.