Edgetech 2000-CSS, Руководство пользователя

Страница: 91 / 101

6-7
there will be a smooth sequence of rising tones going from 2 to 3.9 kHz. A set of tones jumping from 2 to
3 kHz means that self-test has failed. These tones are generated in software in the towfish and replicated
on the surface when an EdgeTech topside computer is used to access the Towfish computer subsystem
using the Remote Desktop application. The Self-Test PASS tones repeat until data linkup has occurred
between the topside DISCOVER software, and towfish. Self-Test FAIL tones repeat indefinitely.
There will also be a video acknowledgement of successful self-test and linkup in the topside computer's
DISCOVER display window. Self-test status will also be displayed on an external video monitor if attached
directly to the towfish’s CPU board's VGA connector.
If the topside computer is unavailable and the towfish is dismantled, an external keyboard, mouse and
video monitor may be connected to the towfish’s CPU board to provide some diagnostic testing. An
external power unit will still be required.
6.3.4 Topside Power Unit
Towfish power is supplied either from an individual power/modem unit or from an integrated topside
computer. Voltage and current to the towfish are important parameters. They must be within acceptable
limits for the towfish to work properly. Check the tow cable output voltage with the system connected
and, if possible, the current drain with an inline connection. Cable current should be between 120mA
(Idle) and 250mA.
The topside units supply 400VDC to the tow cable. The voltage at the towfish end of the cable must be
not less than 300VDC to start the system and not be less than 200V during operation.
6.3.5 Command and Data Link
To check that the command and data link over the tow cable is operational, start the Remote Desktop
application on the topside control computer. There is normally a shortcut on the EdgeTech Desktop for
this. The towfish's PC screen should appear in a window on the topside computer screen. This will appear
as a yellow desktop with the sonar application dialog box visible. If this is successful, then the command
link is working.
6.3.6 Data link
A good, quick qualitative test of the data link and towfish electronics is to perform a rub test on each
transducer. Set the Range to 200 meters for both frequencies and start the system running in HDM mode
for both. Set screen gain to +30dB for both frequencies and briskly rub each aft transducer face one at a
time. A dark band should appear on the sonar processor screen corresponding to the side rubbed.
Data throughput rates on the uplink (vehicle to topside) can be critical in getting smooth data from the
towfish. The data throughput rate can be checked using EdgeTech supplied utilities at each end of the link