NT-2000 REF Manual
User-Level Troubleshooting
5-9
5 . 1 2 . E x t e r n al C o n t r o l P r o b l e m
The following description of the symptom assumes that your NAVTEX receiver was
properly working for some time after initial installation time.
Symptom
Suggested Solution
Alarm indications cannot be
controlled remotely from IBS / INS
terminals despite correct
connections to the rear panel
RS–422 connector.
1. Check to be sure that the RS–422 port is
enabled ( set to
ON
). See paragraphs
4.11.1 through 4.11.4 for details.
2. Check to be sure that the communications
protocol of your application matches that
of the RS–422 port. See paragraph
4.11.2.2 for details.
3. Check the bit format and baud rate of
your application match those of the RS–
422 port parameters. See paragraph
4.11.4 for details.
4. Suspect that some of the internal
connections to /from the connectors have
become loosened or broken. Ask your
dealer/qualified engineer to check for
faulty wiring harness terminations.
5. Run the self–diagnostic tests as per
paragraph 4.12, and check the results of
the RAM and ROM tests.
If the indication of either result is
“
FAILED
,” suspect that the CPU PCB has
become defective. Ask your dealer/
qualified engineer to check the PCB and
related wiring harnesses first and to
replace it if necessary.