User's Manual

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4) HROU Optic Comp Operation
HROU(HMRU) has the function of automatically compensating for optical loss. It can do the
work for up to 10dBo of optical loss. Set “TX OPTIC COMP” of HROU as "ON." Optical
compensation of HROU can not be made without communication with such units in upper level
as ODU or OEU. For 1dBo of optical loss, basic TX OPTIC ATT is 24dB; for 10dBo of optical
loss, TX OPTIC ATT is 4dB. OPTIC COMP works only one time before it stays dormant.
The figure below shows a screen for OPTIC Information in HROU GUI.
LD POWER means output level of HROU Laser Diode, which is sent to a upper unit by HROU.
PD POWER means input level of Photo Diode to be received from a upper unit.
Figure 6.4 – Optic information window
During optical compensation, the Result window shows "Processing" and then a result value.
There are three types of results as follows:
1. Success: The optical compensation is normally made.
2. Over Optic Loss: Generated optical loss is more than 12dBo.
3. Communication Fail: Communication with HROU is in poor conditin.
If HROU does not make optical compensation, there will be errors in the budget of
system link. It can cause lower output level or make Spurious Emission not satisfying for a
standard.