System Information.app. You should see at least two entries:
Hardware > Thunderbolt: mTape, Sonnet, MagStor, etc.
Hardware > SAS: Ultrium, IBM, HP, Quantum
SAS, power cycle the Thunderbolt device and the LTO drive. If you're still not seeing anything listed under
SAS, restart your Mac.
System Information.app > File > Save > (Your Mac).spx
Window > Console (Shift-Command-C)