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WCM1100 / WCM3100 / WCM-Serial / LHM1000 / LVM2000 User Manual
76-02-082 Rev N
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5.9.2.4.4 Bit Error Rate
The bit error rate is calculated based on the number of errors received as a rate based on
the total received bit count.
During a short test the BER should usually be 0, however rates of 10-3 are considered
unavailable, whilst 10^-6 is severely errored and indicate major problems with the line.
5.9.2.4.5 Clear Screen
Typing <C> during a test will clear the test results resetting the counters to 0. This should
always be done before starting a test to ensure any errors encountered before the loop
was applied are cleared.
5.9.2.4.6 Inject Error
Typing <E> will inject a single bit error into the bit stream.
5.9.3 Test Pattern (for LVDS WAN ports)
This Test pattern generator is only available for LVDS WAN ports.
The Test pattern generator allows a BERT test to be performed on the WAN interface.
When the Test pattern is enabled, the WAN port is disconnected from the LAN traffic as
the BERT pattern will overwrite the payload.
Typically a BERT test is performed with a loopback applied at a remote point in the
network. The WCM unit supports request of a loop at the remote WCM, however for fault
diagnosis intermediate node loops may be required. With intermediate node loops, it is
vital to ensure that the Test pattern is enabled before the external loop is applied otherwise
LAN traffic may be looped. Possible loopback positions are shown below:
