Simrad FS70 -, Operator'S Manual

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FS70 Trawl Sonar System
74
974-24007001/5.0
5 Troubleshooting and Maintenance
5.1 Introduction
This section provides instructions for the proper handling, maintenance and troubleshooting
of the FS 70 Trawl Monitoring System.
5.2 System overview
The Simrad FS Trawl Monitoring System FS 70 consists of wheelhouse electronics and a
trawl unit. The wheelhouse electronics include the display unit, the FS Processing Unit,
and the PWR/TTM interface unit. The trawl unit electronics include the sonar head with a
integrated sensor module, receiver transducer, and up to four catch sensors and door
spreads sensors. In addition to the above equipment, but not supplied by Simrad, the
system requires a winch with slip-rings, and a trawl cable for connection of the FS trawl
unit to the wheelhouse electronics.
The FS PWR/TTM unit contains the power modules to provide the Test Voltage, the 120
and 200 VDC @ 1 A maximum for powering the trawl unit electronics, and the voltage and
ampere meters. The low-frequency telemetry adapter “LF 1” Low Frequency PCB and the
telemetry translation module “TTM” PC interface is now incorporated into one unit.
With the FS 70 system, the trawl cable connects directly to the PWR/TTM unit.
Furthermore, the compensation for signal loss over the long trawl cable is done
automatically within the Processor Unit each time it is powered up. In this way changes to
the cable loss do not affect the intensity of the sonar return displayed.
5.3 Handling & maintenance
The most common causes of failures to the Simrad FS Trawl Monitoring system are:
1.
Trawl cable and/or winch slip-ring problems,
2. Sonar head and sensor module connector and interconnect cable failures,
3. Excessive impacts and/or physical damage to trawl unit electronics.
In all three cases, proper handling and maintenance can significantly reduce the frequency
of FS failures. The following sections outline the recommended handling and maintenance
for the FS system.