EXFO IQS-1600 High-Speed Power Meter for IQS-500/600 - Manual (Page 75)

Performing Acquisitions
High Speed Power Meter 67
Starting the Acquisition
You can also start the acquisition in the Graph tab by clicking the Start
button the same way you would in the Control tab.
To enter a name for your acquisition, type it in the File box of Data
Acquisition File. The default extension is .tra.
I
MPORTANT
If you change units on one or more channels using Relative or
Absolute mode and that you had enabled Graph mode, the Graph
and Start buttons might automatically disable themselves if the
resulting changes are not compatible with the base unit used in the
graph.