Raisecom RC802-30B-FV35-S1 User Manual - page 12
There is an error code test unit inside this series device, and the main purpose of this unit is
that produces pseudo random sequence (2E15-1) and sends them to optical line. This
sequence can be uploaded to proper data channel through configuration, then via many
loop back mode the returned sequence is sent to device for testing. The testing result will
be displayed by the PWR/PAT indicator on front panel. When error code is captured the
PWR/PAT indicator turns to green and keep for at least one second. If there is no new error
code occur the PWR/PAT indicator will come back to steady yellow status.
The device will add test sequence to user data channel after the error code test function is
enabled. This function is available in fractional mode and unframed (transparent) mode,
and when it is enabled the V.35 operation will intermit.
Notice: The error code test function can be operated with many loop back test. When the
local dual-direction loop back function is disable the loop back can be realized by fiber, but
the dual-fiber S3 and all single fiber are forbidden. At the time when PWR/PAT indicator is
steady yellow it indicates that correct test code was received. If the remote dual-direction
loop back is enabled accompanied with error code test, it means the whole information
process will be tested.
4. The 5
th
bit: RC CLK Phase choosing dip-switch (default OFF)
SW5-5
Phase Choosing
ON
RX CLK Reverse Phase
OFF
RX CLK Positive Phase
The RX CLK phase choosing is provided according to the different V.35 clock and data
phase of different brand router. On Cisco series router the test result of V.35
synchronization WAN interface is passing when this device is connected and its RX CLK is
Positive.
RX CLK is Positive: Data will be sent to RD signal during RX CLK falling edge.
RX
CLK
RD
RX CLK is Reverse: Data will be sent to RD signal during RX CLK rising edge.
RX CLK
RD
Notice: The relationship of TX CLK and TD phase of this series device is auto-adjusted, so
users need not to configure it.
5. The 6
th
and 7
th
bit: Loop back dip-switch (default OFF)
SW5-6
SW5-7
ON Dual-direction
loop back
enable
Local loop back
OFF Dual-direction
loop back
disable
Remote loop
back