During service expansion , A new card Cis placed at the OSN6800 Equipment (V100R004C00SPC510), After loopback between TX and RX ,and force enable the laser, R-LOS alarm generate at the new TOM card ，then check the performance at NMS, the input power is -60dBm.but the real input power is -12bBm tested by Power meter.
TN11TOM Client side interface report R-LOS alarm.
1 Checking the optical module , it is a type of Signal testing module, the interface is forced to light in the client side, it is white light without signal swing. So report R-LOS alarm. It is normal.
2 The R-LOS alarm disappear after the client signal access, and the input power is normal.
There are two method detecting input power:
1 LOS OF POWER: Only detecting optical power, report R-LOS if there is no power input.
2 LOS OF SIGNAL: report the R-LOS alarm base on the signal swing. If the signal hold on one state, or the signal is all 1 or all 0, It will report R-los alarm even the strong power.
The card report R-LOS alarm, firstly exclude the failure of Optical module, secondly exclude the fault caused by wrong configuration (alarm reversion, alarm filtering...).thirdly, check the type of module to sure whether there is a signal test or power test.
The R-LOS alarm means normal condition when there is no client signal access when use the signal test type.