To determine the exact trigger time of the waveform acquisition, use the ":HISTORY:TIME? 0" command, where 0 refers to the latest acquisition record.
To determine the exact trigger sample number, use the ":WAVEFORM:TRIGGER?" command. The number of samples that would be read from the scope is:
No. of Points = Record Length * 1.001
Since the trigger sample number is counted from the first point, you can ignore the last 0.1% of the record length. For example, if the record length is 10k points, the total sample points must be 10,000 *1.001 = 10,010 points. You can ignore the last 10 points, 10,000*0.001 = 10 points.
The Time Zero can be counted from the first point.
Sample Rate(SR): ':WAVEFORM:SRATE?'
Trigger Position(TP): ' :WAVEFORM:TRIGGER?'
The Time Zero is at this Trigger Point.
So the relative time of the first point of the wavefrom data is SR*TP*(-1).
Please refer to the attached image file of the DL850 ScopeCorder Manual Instruction Manual IMDL850-01EM Chapter 3, for more information on how the total number of sample points is calculated.
Yokogawa data acquisition systems give you the most flexibility and power to measure, display, store, and even actuate any number of physical or electrical phenomena.