EXFO FTB-800 Series for FTB-1 - Manual (Page 122)

Test Setup - Test Configurator, Timer, and System
112 FTB-700G/800 Series
Clock

Frequency (MHz) displays the frequency of the received signal rate.

Offset (ppm) displays the positive or negative frequency offset
between the standard rate specification and the rate from the received
signal. The background color is used to indicate if the received clock
meets (green) or not (red) the standard rate specification.
Ext Clock Out
Note: Available when the Clock Mode is set to Internal, or Recovered,.
Allows to set the clock generated on the EXT CLK port.

Interface Type allows the selection of the clock interface:
DS1 (default), E1, and 2MHz.
Ext Clock Out on a green background indicates that a valid clock is
generated on the EXT CLK port.
LOC on a red background indicates that no clock is generated on the
EXT CLK port.

LBO (Line Build Out), available with DS1 only, allows the selection of
the interface Line Build Out that meets the interface requirements over
the full range of cable lengths: DSX-1 (0-133 ft) (default),
DSX-1 (133-266 ft), DSX-1 (266-399 ft), DSX-1 (399-533 ft), and
DSX-1 (533-655 ft).
Signal Standard Rate specification
DS1 1544000 ± 8 bit/s (± 4.6 ppm)
E1 2048000 ± 10 bit/s (± 4.6 ppm)
2MHz 2048000 ± 10 bit/s (± 4.6 ppm)