FS70 Trawl Sonar System
90 974-24007001/5.0
NOTE: If any of the above host Downlink commands have issued a requested and a
reply is not Uplinked back to the host, those errors are posted in the log file. Therefore
you are having some Downlink or Uplink telemetry problem. If this is the case you
will have to troubleshoot the problem.
The problem may be located in the TTM/LF1 telemetry boards or the LF1 telemetry boards
located in the head. The best way to determine the problem would be to replace the head or
the TTM with a serviceable spare unit.
Problems and the possible causes:
Complete system and/or
calibration failure - cable
gain at maximum, telemetry
errors are logged in the file.
Check for telemetry errors. If none, then problem is
with the sonar head or the TTM unit.
Sonar head operates
correctly but pauses
periodically - may not have
sensor module data
Check Message Log for errors. If multiple errors are
present then the internal sensor module may be
defective. Check by restarting the system.
Sonar head operates
correctly but image is
skewed or distorted.
Check for calibration errors in sonar head positioning.
If calibration errors are present then sonar head may
be defective. Otherwise check that sonar head is
properly mounted in trawl housing.
Sonar head operates
correctly but the cable gain
is higher than normal and
telemetry errors may be
present.
Problem may be with the sonar head or the TTM
interface unit.
Replace sonar head and repeat the test. If problem re-
occur then the problem is with the TTM/LF1
otherwise the problem is in the previous sonar head.
Internal sensor module electronics is defective.