EXFO RTU 310-310G IP Services Test Head - Manual (Page 414)

System Tabs
402 RTU-310/310G
Clock Synchronization

Frequency: The Frequency alarm indicates if the received signal rate
meets (green) or not (red) the following rate specifications.
Frequency Analysis

Frequency (bps) displays the received DS1/2M/E1signal rate in bps.

Frequency Offset displays the positive or negative frequency offset
between the standard rate specification and the rate from the received
signal. Frequency unit can be set to bps, or ppm. The default setting is
bps.
Note: The frequency value displays “>50” when the frequency offset is bigger
than ±50 ppm.
Signal Rate specification
DS1 1544000 ±15 bps (±9.2 ppm)
E1 2048000 ±19 bps (±9.2 ppm)
2MHz 2048000 ±19 Hz (±9.2 ppm)