Kongsberg EM 2040C, Руководство по обслуживанию

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External Synchronisation
The Processing Unit (PU) is equipped with a connection for interface to an external
synchronisation system.
External synchronisation input/output
When multiple echo sounders are employed on a vessel it is essential to optimize
the timing of the transmitting of each system. The Kongsberg Maritime K-Sync
Synchronising Unit provides highly configurable timing.
The EM 2040C provides the following synchronisation signals:
EM 2040C external synchronisation signal characteristics
Signal Type Active
Ready To Transmit (output)
Open collector output from
isolation unit High
Trig out (output) Open collector output from
isolation unit
Low
Trig in (input) Optical isolated input High
•
Ready To Transmit
: This is an output signal from the EM 2040C to the synchronisation
system that goes active when the EM is ready to transmit. The signal is inactive when
the echo sounder is transmitting, receiving or processing samples.
•
Trig out
: The EM 2040C issues a trig out signal. The trig out signal starts before the
first transmit pulse and is terminated after the end of the last transmit pulse. For EM
2040C all pulses in one swath are transmitted simultaneously. With dual swath, two
pulses are transmitted in sequence. The length of this trig signal is 0.7 ms plus the
total TX signal length. For CW pulses the actual TX pulse is 1.5 times the nominal
pulse length (because of amplitude tapering).
Reference to the Raw range and angle 78 datagram:
The transmit time for the TX pulse is referred to the centre of the pulse.
The total length of the TX pulse is given in the datagram (Signal length).
The time delay from the leading edge of the trig out pulse to the centre of the first
TX pulse is:
– 506 us + 0.5 * signal length.
Example of signal length (200 kHz, Normal sector):
– Short CW: 101 µs
– Medium CW: 288 µs
– Long CW: 865 µs
– Short FM: 3 ms
– Long FM: 12 ms
Cable layout and interconnections