Specifications

Installation and Operation Manual Chapter 6 Troubleshooting and Diagnostics
FCD-E1LC Ver. 1.0 Testing the Unit 6-23
Transmission
Plant
User's
Equipment
Local FCD-E1LC
Data
Channel
Main
Link
Remote FCD-E1LC
Sub Link
Main
Link
Data
Channel
User's
Equipment
Sub
Link
User's
Equipment
User's
Equipment
Processor Processor
Figure 6-9. Sublink Remote Digital Loopback
Data Channel Loopbacks
Data Channel Local Loopback (LP LOC CH 1, LP LOC CH 2)
The data channel local digital loopback is performed towards the user’s
equipment connected to the selected local data channel (channel 1 or channel 2).
The loopback is performed by connecting the data channel transmit signal to the
input of the receive path as shown in
Figure 6-10.
The test signal is provided by the local user’s equipment, which must receive its
own transmission. This test checks the connections to the local user’s equipment
and the data channel interface.
When an alarm condition is present on the main link, the receive data is held at
MARK. Under these conditions, it is not possible to perform BER measurements
when a local channel loopback is connected. If you try to measure BER, the result
is invariably errors.
Local FCD-E1LC
Processor
Main
Link
Data
Channel
User's
Equipment
Sub
Link
User's
Equipment
Figure 6-10. Data Channel Local Loopback
Data Channel Remote Loopback (LP REM CH 1, LP REM CH 2)
The data channel remote loopback is performed towards the user’s equipment
connected to the selected data channel of the remote FCD-E1LC. The loopback is
performed by connecting the local data channel receive signal to the data channel
transmit input without passing through the local data channel interface, as
shown in
Figure 6-11 . The test signal is provided by the remote user’s equipment,
which must receive its own transmission.
Note