Review the section 'User Functions' on the following page: http://scanimage.vidriotechnologies.com/display/SI2015/ScanImage+API
There you see how to obtain the last frame acquired by ScanImage. The 'lastStripe' object has several fields that are relevant:
- frameNumberAcqMode
numeric, number of frame, counted from beginning of acquisition mode - frameNumberAcq
numeric, number of frame in current acquisition - acqNumber
numeric, number of current acquisition - epochAcqMode
string, time of the acquisition of the acquisiton of the first pixel in the current acqMode; format: output of datestr(now) '25-Jul-2014 12:55:21' - frameTimestamp
[s] time of the first pixel in the frame passed since acqModeEpoch - acqStartTriggerTimestamp
[s] time of the acq start trigger for the current acquisition - nextFileMarkerTimestamp
[s] time of the last nextFileMarker recorded. NaN if no nextFileMarker was recorded