Raisecom RC905-EE1 User Manual - page 14
14
Chapter 4 Troubleshooting
If there is any problem during installation and application please try to solve it according to the
following suggestions. If it is not solved yet, please contact technical staff for support.
I.
Power indicator PWR is OFF
There is fault with power supply system.
II.
Ethernet link indicator LNK is OFF
Check whether the network cable is disconnected.
Check whether the link type is matching the straight cables shall be used to connect switches
and HUB’s; the cross-over cables shall be used to connect routers and NIC’s.
Check whether the transmission bit rate is matching; the bit rate of the Ethernet ports of the
equipment connected with interface converts shall be auto-negotiation or fixed 10M.
III.
Link loss alarm indicator LOS of E1 link is ON
LOS alarm indicates E1 interface cannot receive signals.
Check whether E1 input signal link is connected well and whether wire order of 120ohm
twisted pair cable connector is correct.
Check whether there is any power off with the equipment connected with interface
converter.
Please check whether E1 receive link is disconnected with bit error tester.
IV.
LER indicator is on
It indicates that at least one kind of alarm occurs among E1 Loss of frame alignment (LOF),
upstream link alarm (AIS) and checkout fault (CRC).
When equipment is working at transparent mode, LER alarm means AIS alarm only.
Please check whether there is any power off with the E1 uplink equipment.
Please check whether the interface impedance setting is correct. In the case of using
120ohm twisted pair cable connector, check whether the wire order is correct and whether
the connection is loose.
Please check whether E1 transmit link is disconnected with bit error tester, and whether the
bit error rate is beyond limit.
LOF alarm causes LER indicator flashing or blinking, it indicates there is loss of frame
alignment of E1 signal.
When the equipment works at transparent pattern, there shall be no LOF alarm.
Please check whether the interface impedance setting is correct.
Please check whether bit error rate is beyond limit with bit error tester.