Raisecom Technology Co., Ltd
8
The purpose of switch is for E1 remote loop-back test, fault transfer, Ethernet packet length
configuration, duplex configuration, insulation function configuration of Ethernet ports, selection
between 232 and 485 of NM ports, selection between local and remote NM.
6 bits DIP-switches on left side:
z
1
st
bit: enable/disable loop-back
1
st
Loop-back
OFF Disable
ON Enable
z
2
nd
~4
th
bit: loop-back selection at remote end
2
nd
3
rd
4
th
Loop-back
OFF OFF OFF 1
st
E1
OFF OFF ON 2
nd
E1
OFF ON OFF
3
rd
E1
OFF ON ON 4
th
E1
Note
: Loop-back selection only can configure one test method: single E1 channel loop-back.
When enable loopback function, loopback selection is valid if there is no any alarm. If single E1
channel loop-back is testing, the other branches are working without any disturbance.
Figure: sketch map of setting local loop-back at local end
Note
：
When set loop-back at local end, DIP-switches (1
st
~4
th
) of Ethernet multiplex at remote
end should be default state ‘OFF’.
z
5
th
bit
：
Enable or disable fault transfer function
If disable fault transfer function, it complies with AIS function of traditional multiplexer. If E1
receiving signals on remote end are loss
，
the E1 outputs of local end are all ‘1’
；
while if optical
signals of local end are loss
，
all E1 outputs are all ‘1’ at local end.
Fault transfer function is designed for user having special demands. If occur signal loss on
any direction of optical interface after enabling fault transfer function
，
EI interface on both side
do not output HDB3 code. Signal loss will occur at E1downterminal equipment, but not AIS
alarm.
5
th
bit
Fault transfer function switch
OFF
Disable
（
comply with AIS of traditional multiplexer
）
Local
Remote
Fiber
E1
E1
M
u
lt
ip
le
x
er
Bit error tester
M
u
lt
ip
le
x
er