User's Manual

Confidential & Proprietary 133/139
Checking Communication LED of OEU
Step1 : checking whether communicate with BIU(ODU)
Check if TXD1 and RXD2 LEDs in OEU front LED make communication. Receiving FSK signals
from BIU, OEU sends requessted status value to BIU. During reception, RXD1 LED flicks.
During tramsmission, on the other hand, TXD1 LED flicks. At this time, you need to check if
whether to use a corresponding OEU is checked on (See "whether to use BIU OEU/ROU").
Step2 : Checking whether communicate with ROU
OEU do as Hub. OEU has two optical port. One is connected to ODU and the others is
connected to ROU. Communication with ODU is checked at above step1
Step2 is checking stage whether OEU communicate with ROU. OEU request status to ROU and
then TXD2 is flicked and if respones data received from ROU RXD2 LED is flicked
OEU Optic Comp Operation
OEU has the function of automatically compensating for optical calbe loss. It can do the work for
up to 5dBo of optical loss. Set “TX OPTIC COMP” of OEU’s Eoptic as "ON." Optical
compensation of OEU can not be made without communication with such units in upper level as
ODU. For 1dBo of optical loss, basic TX OPTIC ATT is 12dB; for 5dBo 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 OEU GUI.
LD POWER means output level of OEU Laser Diode, which is sent to a upper unit by OEU. PD
POWER means input level of Photo Diode to be received from a upper unit.
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 5dBo or more.