Unit installation

FS70 Trawl Sonar System
64 974-24007001/4.1
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: