Hi Tom,
With a single Rosetta 200 connected with the Symphony card, you would just set the Symphony to Internal. Logic it self does not really clock from the hardware like another piece of hardware would. If you add any other digital hardware you would then have a situation where you would have one device on internal and the other on external.
If you have any other questions please let me know. Also feel free to call tech support (310)584-9394 or E-Mail
support@apogeedigital.com
Best Regards
Chris Lawson
Apogee Electronics