Nevion 3GHD-OE-L-2-SFP - Manual (Page 10)

3GHD-OE-L-2-SFP Rev. C
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3.3.2 Display optical input power
The LED’s can be used as an optical power meter. This is practical under installation of the
module. The power measurement is not accurate but can be used as an indication of optical
power strength. Remember to turn this function of after installation. When all LEDs are green
the optical input power is more than -6.5dBm. When all LEDs are off input power is below -
25dBm.
The DOP can only be turned on from the DIPswitches. DOP is turned on by DIP#3.
Table 3 Displaying optical input power
Optical input power Status LED LOS/lock1 LED LOS/lock2 LED
More than -6.5dBm Green Green Green Green
-7.0dBm to –8.5dBm Yellow Green Green Green
-9.0dBm to –10.5dBm Red Green Green Green
-11.0dBm to –12.5dBm Green Green Green
-13.0dBm to –14.5dBm Yellow Green Green
-15.0dBm to –16.5dBm Red Green Green
-17.0dBm to –18.0dBm Green Green
-18.5dBm to –19.0dBm Yellow Green
-19.5dBm to
–20.0dBm
Red Green
-21.0dBm to
–22.0dBm
Green
-23.0dBm to
–24.0dBm
Yellow
Below -25dBm Red
3.3.3 Automatic change over
Dual optical converter has an automatic change over module. This module has the possibility
to have an automatic change over on the input. This can be used in redundancy systems
where the user wants automatically switch to a backup port when the main input loses signal.
This function can be selected with DIP#7. From GYDA this function can be turned on for each
converter. Each converter can be configured to what is main and backup input by DIP#2 and
DIP#5 or from GYDA.
3.3.3.1 Trigger condition
Loss of optical power trigs the automatic change over. When the main input lose optical
power the backup input is selected. When the backup input is active an alarm is displayed in
GYDA. When the main input optical power is restored the converter switches immediately
back to main input and alarm is restored.
Note that bit error or loss of lock on reclocker does not trigger the automatic
change over.