EXFO IQS-1600 High-Speed Power Meter for IQS-500/600 - Manual (Page 93)

Using the External Trigger and Analog Outputs
High Speed Power Meter 85
Analog Output (IQS-1610, IQS-1620)
When using your high-speed power meter with rising optical power,
saturation of the scale converter will be reached when +++++++ is
displayed. At that moment, the voltage in the analog output will be 2.15 V.
Even with +++++++ displayed, the optical power can still be increased
further and the analog output will continue to increase proportionately. The
voltage reading on the oscilloscope is then 3.95 V for HR1 to HR4 and LR1
to LR4, and 4.4 V for LR5 and LR6.
To set the analog output properties:
1. From the main window, click Settings.