Unit installation

FCD-E1 Installation and Operation Manual Chapter 6 Troubleshooting and Diagnostics
Testing FCD-E1 6-17
4. Repeat step 3 to change the link and display CH1, meaning that the displayed
loopback state pertains to data channel 1. Second row shows the loopback
type and its current state: ON or OFF.
5. Repeat step 3 to change the link and display CH2, meaning that the displayed
loopback state pertains to data channel 2. Second row shows the loopback
type and its current state: ON or OFF.
6. After you selected the desired link, bring the cursor to the left-hand field in the
second row, and scroll to display the desired type of loopback: LOCAL LOOP
or REMOTE LOOP (for ML and SL), LOCAL LOOP, REMOTE LOOP, BERT or
INBAND LOOP (for CH1 and CH2). The right-hand field shows the current
state of the selected loopback: ON or OFF.
7. To change the test state, bring the cursor to the right-hand field in the second
row, and scroll to display the desired state (ON or OFF); the second row shows
the new state of the selected test (for instance, ON).
8. Press ENTER to activate or deactivate the displayed test; the TEST indicator
lights if the test is activated, or goes off if no tests are active.
Operating Loopbacks from a Control Terminal
The diagnostic loops can be activated from a control terminal by entering the
following commands:
LP LOC ANA ML LP REM ANA ML LP LOC DIG ML LP REM DIG ML
LP LOC ANA SL LP REM ANA SL LP LOC DIG SL LP REM DIG SL
LP LOC CH1 LP LOC CH2 LP REM CH1 LP REM CH2
LP INBAND CH1 LP INBAND CH2 LP BERT CH1 LP BERT CH2
For general instructions on entering FCD-E1 commands from a control terminal,
refer to Chapter 4.
User-Controlled Loopback Tests
The test and loopback functions are described in the following paragraphs. The
test functions are identified by the command used to activate the corresponding
test/loopback function. The figures illustrating the signal paths for each loopback
type show the FCD-E1 version equipped with the sublink.
No channel loopbacks are available for the Ethernet interface. In addition, main
link loopbacks should not be activated on an FCD-E1 with Ethernet interface while
the Ethernet interface is connected to the LAN. This would cause a state of
permanent collision on the LAN (this would prevent other users from using the
LAN as long as the loopback is connected).
Main Link Local Analog Loopback (LP LOC ANA ML)
This loopback is performed by connecting the main link transmit signal to the input
of the receive path, as shown in Figure 6-1. This returns the transmit signal of each
port (channel and sublink) on the receive path of the same port. The test signal is
provided by the equipment connected to the local ports: each one must receive its
own transmission.