Simrad FS70 -, Operator'S Manual

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FS70 Trawl Sonar System
88
974-24007001/5.0
Troubleshooting system power problems:

Check TTM Interface unit panel meters for voltage and current, ensure unit is on and
confirm voltage meter indicates 200 VDC.

If no current is indicated then turn power off and disconnect the third wire cable from
the TTM Unit. Check wiring continuity between the MS connector and the 2 pin
connector at the trawl unit. If OK, then the sonar head needs servicing.
5.4.16 Host FS70 Software Start-up Sequence of Events
In this section we will be addressing the telemetry communication and highlighting the
action/problems and the possible causes.
What happens when you start up the host software?
When you start up the FS host software you are establishing
“Digital”
communication with
the TTM boards located inside the Power/TTM unit.
The communication is established between the PC and the TTM using the host software
commend by clicking on “Detect Head” if the host do not detect the “Head” you will have
to troubleshoot where the problem may be as indicated below.
Troubleshooting head detection problems:

Check COM port is activated in host software. If not, then activate the COM port and
re-detect head.

If head not detected, then check connection between the PC and TTM. If OK, the TTM
needs servicing.
After the host has detected the “digital side” of the TTM board, the “Analog” side of the
TTM board and via the LF1 telemetry board unit completes the downlink communication
through the LF1 telemetry board located in the sonar head.
5.4.17 What happens when you click “RUN”
The next steps after the host software is detected and you hit the “Run” button are:

Cable Calibration
The CPU board will request a series of transmit pulses from the transmitter to initiate the
cable calibration. While this is occurring the surface unit (via the TTM/LF1 board) will
increase/decrease the values (returned signal “echo’s”) via the receiver board and will be
uplinked and written to the Digital-to-Analog Converter “DAC” such that the Gain-Detect