Raisecom Technology Co., Ltd
18
is within limit standard.
LOF alarm can result in LAL indicator flicking or ON, this means E1 signal is out of frame.
If the device works in transparent mode, there is no LOF alarm.
Please chick if interface impedance switch is set correctly.
Please check if bit error rate is within limit standard by bit error rate tester.
If your E1 link has equipments of other brands, there may be a few LAL flicking alarms
when the converter is just powered on, this is normal. Please wait for a while, and the
alarm will disappear. If LAL is flicking for a long time, there must be something wrong with
the link.
CRC alarm means there is severe bit error in E1 link.
In transparent mode, there is no CRC alarm.
CRC alarms may accompany with LOS or AIS, please check if bit error rate is within limit
standard with bit error rate tester.
If the suddenly appeared CRC alarms make LAL indicator flicking, which may result in
network disconnecting, basically this is caused by initializing link process when the
equipment is just reset. In this case, large traffic should be paused for a while, and the link
will recover in 10~30 seconds automatically.
If CRC checkup optional switch---- 7
th
bit of SWS is ON (CRC disabled), then this alarm
indicator would not be caused by CRC.
5
．
RAL ON
Remote alarm, this means there is something wrong with remote end device of receiving
direction, please check the link between TX and RX.
6
．
Severe packets loss
If you need to set the converter in E1 fractional mode (refer to the definition of 1
st
bit of
SW1), there must be two interconnected equipments in both sides, one in master clock
mode and the other in slave clock mode.