Yes. The slow axis (galvo) follows a (smoothed) sawtooth pattern. After each frame, the slow axis flies back to the starting position.
In ScanImage 5.1 and ScanImage 2015/2016, you can adjust the flyback time in the section of the configuration dialog.In ScanImage 2015/2016, you may need to select 'Advanced Timing Controls...' to access this setting.
You can plot the output waveform of the galvo in Matlab with the following command:
Useful ScanImage Links: