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CM2 Sidescan Sonar User Manual
Connecting...
The
message indicates that the towfish has started its initialisation and that the tow cable
telemetry is being set up. This message should disappear when the telemetry link has been established and
the towfish has started running.
Note that initially the towfish runs silently, i.e. in the muted mode. This is to allow the telemetry link to
complete its optimisation without any interference from the transducer drive voltage. The muted period lasts
for the first 80 pings.
As soon as the towfish runs the Trigger indicator flashes, once per ping.
Wait for the gain to rise to a point where the "waterfall" display on the screen has filled in to show "noise"
from the environment. At this point the operation of the towfish can be given a basic bench check known as a
"rub test". Without touching the metal of the towfish with either hand, place one hand briefly on the face of
one of the transducers. This should result in an increase in signal on the appropriate side of the waterfall
display for the time that the hand is that position; at least until the automatic gain control reduces the signal.
Then test the other side in the same way. Note that although this is called a rub test, no rubbing action is
necessary: the signal is induced capacitively, not by mechanical action.
Quick Select
The
menu, accessed by pressing the spacebar, can be used to change the sonar range and
frequency or to stop the towfish. The spacebar can also be used to clear the
(*If the tow cable is higher in resistance than a certain value, the towfish will detect that its internal voltage
has dropped below nominal. In this case it will command the STR, or other unit, to increase its supply to the
tow cable by a further 24V.)
Spares and Tools
Always carry spare breakable washers. A 5mm hex key is the only tool required in normal operation. Every
towfish is supplied with a kit (CM2-TSK) containing minor spares and consumables.
Version 3.6 (2008)
10
3. Installing the System
Quick Select
menu.
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