Raisecom
RCMS2902-2E1GE-BL Product Description
8 Appendix
Raisecom Technology Co., Ltd.
24
8.2.4 Why is the L/R LOS(1-2) LED lighten up?
This indicates that a LOS alarm in Rx direction occurs at the E1 tributary. It also means that
no HDB3 coding is input.
Check whether the E1 interface is connected properly.
Check whether the wring of the 120 Ω cable is correct.
8.3 Terms
A
Automatic Laser Shutdown
(ALS)
When the fiber of the optical interface is pulled out or
when the output power of the optical transmitter is over
great, the optical interface shuts down the laser
automatically to avoid maintenance and operation risks.
B
Back-pressure flow control
Inform the upstream interface of traffic congestion to
make it slow/stop sending data unless congestion
disappears.
C
Card
An electronic module, composed by the chip and other
electronic components installed on a flat and hard
Printed Circuit Board (PCB). The PCB has conductive
circuits for connecting these components.
E
Electromagnetic Compatibility
(EMC)
The capability that a device/sub-system can work
improperly in an electromagnetic environment without
generating unbearable electromagnetic disturbance on
other devices or sub-systems in the electromagnetic
environment. It is an important metric for system
reliability.
Ethernet
Ethernet is created by the Xerox company initially.
Xerox convinced Digital Equipment Corporation
(DEC), Intel, and Xerox to work together to promote
Ethernet as a standard. It is the most widely-used Local
Area Network (LAN). The speed of Ethernet includes
10 Mbit/s, 100 Mbit/s, 1000 Mbit/s, and 10 Gbit/s.
Ethernet adopts the CSMA/CD access control mode and
complies with the IEEE 802.3 standard.
F
