EXFO FTB/IQS-88000 Series Power Blazer for FTB-2/2Pro/500/IQS-600 - Manual (Page 127)

Test Setup - Test Configurator, Timer, and System
Power Blazer 115
Clock

Framing, available with DS1 and E1, allows the selection of the
interface framing.
For DS1: SF, SLC-96, and ESF (default).
For E1: PCM30 (default), PCM30 CRC-4, PCM31, and PCM31 CRC-4.
REF OUT
Frequency (MHz) displays the frequency of the generated clock signal on
the REF OUT port based on the test interface/rate.
Clock Out indicates that a clock is generated on the REF OUT port (green)
or not (red).
Note: The Ref Out clock port provides a consistent reference for eye diagram for
10G and above optical devices. This clock is not generated by the optical
devices thus impacting the accuracy of the different measurements derived
from the eye diagram. As such this port should be used for basic
measurement and not for optical device formal qualification.
Backplane
Note: Available when the Clock Mode is set to External, Recovered, or Internal.
Backplane Clock check box allows, when selected (cleared by default), to
enable the backplane clock based on the selected clock mode.
Backplane indicates that the background clock is generated (green) or
disabled (gray).
LOC on a red background indicates, when the backplane clock is enabled,
that the synchronization is not possible with the selected reference clock.