Reading SMART attributes from external drives connected via USB or FireWire requires that you install the SAT SMART Driver so your Mac can ‘see’ the SMART information on the external drive. The SAT SMART Driver is a kernel extension which extends the operating systems ability to access the SMART data of an external USB or FireWire hard drive.

To install the SAT SMART Driver, launch the Drive Scope application, go to the Drive Scope menu and select, 'Install SAT SMART Driver...'. Once selected, you will be asked to eject all external USB and/or FireWire drives connected to your Mac. Click OK after ejecting your attached USB and/or FireWire external drives. A new window will appear for installing the SAT SMART Driver. Click the Continue button and proceed through until you reach the Installation Type screen. Now click on the Install button to install the SAT SMART Driver onto your Mac. Upon successful installation, we recommend a restart of your Mac. After restart, relaunch Drive Scope and see if your USB and/or FireWire external drives appear in the Drive Scope user interface window.

NOTE: External Thunderbolt drives do not require the installation of the SAT SMART Driver since the macOS supports reading SMART information from these drives.