ALARMS, TROUBLESHOOTING & TESTING
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4. 2 Troubleshooting
Step 1: Establish and verify the E1 WAN link
Check the status LED on the rear panel of the unit at both ends of the link. If either is OFF,
power is not present on that unit. Check the mains connection to the unit. If mains supply is
satisfactory, we recommend that the unit be taken out of service and returned to a repair
centre. Unqualified users should not open the DC3X00 .
DC3X00 with BNC connectors - Step 1A
If the status LED is
RED
or flashing RED/O
FF
, first check that the
SELECT
bit-switch on the
base panel is set to BNC. If it is set correctly, try swapping the E1 LINE BNC connections at
that unit.
If the status LED remains red or flashing red/off, try looping the BNC connections on the unit
with a short piece of cable. If the status LED goes steady green or flashes green/off,
red/green/off or red/green then the external BNC cabling is faulty. Check for cable continuity
and network connections, etc.
DC3X00 with RJ45 connectors - Step 1B
If the status LED is red or flashing red/off, first check that the SELECT bit-switch is set to
RJ45. If it is set correctly, check the connections on the RJ45 cable. Check for cable
continuity and network connections, etc.
Step 2 Establish and verify the DTE link
If the status LED flashes
RED/GREEN
, this indicates that either an LOF or AIS Alarm is
present. In order to distinguish between these, disconnect the DTE signal from the DC3X00.
Then observe carefully the colour sequence of the LED:
a) If the status LED flashes
GREEN/RED/OFF
, an LOF Alarm is present. Check that the E1
configuration is compatible at either side of the link. Check especially that the operating
mode set-ups as set by the base panel bit-switches are the same at both ends of the link.
b) If the status LED flashes
RED/GREEN/OFF
, an AIS Alarm is present. Check that the
remote router port status is
UP
and that the remote router cable is in place.
If the status LED flashes
GREEN/OFF
, check that the local router port status is
UP
and that
the local router cable is in place.
If problems persist, check the DTE cabling configuration. Running
TEST LOOPS
will help to
isolate the problem area - see next section. Transmit and Receive data connections may be
crossed, as may any of the handshaking and/or signalling lines.
Step 3: Bridge/Router configuration
As the DC3X00 is used in a variety of locations and with many different manufacturer’s
equipment it is impossible for us to cover all eventualities here, so please consult other
manufacturer’s operating manual for further information.
