Raisecom Technology Co., Ltd
15
6. Troubleshooting
If you have any problems during installation and usage, try to solve them by the following proposals. If
there is no solution, please contact with distributors for technical support.
These following explanations and solutions of alarm for optical port and LOS alarm of E1 branch aim at
alarm of local end. Please handle it at remote end if alarm occurs at remote end.
z
Green PWR indicator is OFF
Answer: power supply faults. Please check whether power is properly supplied and –48V power
cord does not be connected reversely.
z
GL (red) is ON
Answer: If alarm occurs at local end (L row), GL is continually ON. If alarm occurs at remote end
(R row) GL is flashing.
There are three methods to handle it shown as following,
1. If there is some other red or yellow alarm indicators, except for GL, please resolve
corresponding alarm at first.
2. If no alarm occurs in L row except that GL is still ON at local end, there is HDB3 code error
during receiving signals at E1 link of local end equipment. The reason might be that E1 cable
is too long, too much interference, signal attenuation is over -6dB or poor contact of tie-in.
3. If no alarm occurs in L row except that GL is still ON at remote end, there is HDB3 code error
during receiving signals at E1 link of remote end equipment.
z
Red LOS indicator of optical port is ON
Answer: Loss of reception signal occurs at optical port. Please check whether input of fiber is
connected correctly. Use optical power meter to detect optical power, which should be larger than
reception sensitivity.
z
Red LOF indicator of optical port is ON
Answer: Loss of frame of reception signal occurs at optical port. In this case, optical signal has
been received, but value of optical power is threshold or fiber is so short that reception side is in
saturated status. Detect RX optical power and ensure that optical interface TX has been
connected well at remote end.
z
Red E-3 indicator of optical port is ON.
Answer: The bit error of optical RX signal is over 10
-3.
Please check whether optical RX port has
been connected well and detect reception optical power.
z
Yellow E-6 indicator of optical port is ON
Answer: The bit error of optical RX signal is over 10
-6.
If occur E-6 alarm during operation period,
please check whether optical RX port has been connected well and detect reception optical
power.
z
Red LOS indicator of E1 channel is ON
Answer: Loss of RX signal alarm at E1 channel. There is no HDB3 signal input. Please check
whether E1 port has been connected well, 75
Ω
cable has been connected reversely and 75
Ω
cable order has been connected right.
