www.raisecom.com
User Manual
13
E1 2~4, same way as Bit 1
When executing E1 loopback testing, the Bit 4 of DIP switch SEL is used for selecting the loopback
point, that is, deciding whether the loopback is a remote loopback or a local one. The E1 loopback of
RC831 series device has two directions. The loopback point and loopback direction of the remote
loopback and local loopback are shown in the Figure 4-1 and Figure 4-2.
Multi
ple
xi
ng C
ore
Multi
plex
ing Cor
e
Interface Circuit
In
te
rf
ac
e
C
irc
uit
Figure 4-1 The settings of “remote loopback” on the local PDH multiplexer
Local
Remot
e
Fiber
E1
Sid
e
E1
Sid
e
BER Tester
Figure 4-2 The settings of the “local loopback” on the local PDH multiplexer
L
Note:
1. Before setting up the E1 remote loopback testing, please make sure that there is no alarm at the
optical interface.
2. To set up any loopback on the local PDH multiplexer, the setting of all bits of DIP switch
E1-LOOP on the device at the opposite site must be of the default setting, which is OFF.
3. Please mask all false alarms from E1. If some of the E1 lines (not all of them) are well connected
and there are no LOS alarms on them, the LOS alarm indicators of those unconnected E1 lines will
turn ON and they are false alarms. In this circumstance, press in the MASK switch and all local false
alarms will be masked and disappear, and the corresponding E1-LOS indicators will turn OFF. For
those well-connected E1 lines, the indication for the LOS alarms on them will not be affected by the
change of the status of the MASK switch.
4. The online upgrade function is only applicable when the device is set to be a local site device.
Note that when applying the device normally, please make sure that the online upgrade function is
OFF before electrifying the device. Otherwise, the MCU can not get start.
4.1.3 Default settings
The factory settings of all DIP switches are OFF.
This default setting of the device indicates that:
