R2Sonic 2022, Operation Manual

Page: 29 / 133

Page 29 of 133
Version 3.0 REV r000
Date 25-08-2010
4 Sonic 2024/2022 Mounting: Sub-Surface (ROV/AUV)
4.1 Installation Considerations
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A 1000BASE-T link (best time sync accuracy) is preferred; however, with bathymetry only
information, 100BASE-T will work. 10BASE-T will also work, but is not recommended. Bathy
data requires 2 Mb/s data rate at a maximum ping rate of 60 pings/s. For future
compatibility, please use 100BASE-T at minimum, snippets will not work with 10BASE-T;
however, snippets will work over a 100BASE link.
•
Average power, for a Sonic 2024 is 50W (1A), peak is 100W (2A); for a Sonic 2022 it is 35W
(0.73A), peak is 75W (1.5A). The peak power of 100W (75W) occurs just after transmit and
typically lasts for a few ms (depends on transmitter power setting). If you use a separate
power supply for the sonar, we recommend using a 120 to 150W power source to supply
the head, but less if installing a Sonic 2022.
•
The sonar up/down link is all done through the Ethernet channel. Thus, no other hardware is
required except for the Ethernet media converters (copper to fibre, fibre to copper). As a
precaution, placing additional filtering on the output of the 48V supply to the sonar head is
a good idea to prevent vehicle electronic noise from getting into the sonar head. A common
mode choke, on the 48V line, is recommended. The Bourns (JW Miller) PM3700-50-RC
common mode choke works well (surface mount part). A Bourns 8102-RC choke, which is
easier to install (non-surface mount) can also be used.
•
The supplied deck cable is a special cable with Ethernet pairs which are rated to 3000
meters water depth.
Do not substitute this cable, as the Ethernet data pairs need to meet
certain important specifications . When terminating the Ethernet connections to your own
connector, the Ethernet twisted pairs need to terminate right at the connector pins ,
maintaining the twist on the wires as close to the connector pins as possible. On the
bulkhead connector,
use CAT5, or better Ethernet cable, from the connector, to the
Ethernet media converter. Use adjacent pins for each wire pair. If 100BASE (or 10BASE)
Ethernet is used, only the green and orange pairs are required. All four pairs, including blue
and brown, are only required when using gigabit Ethernet.
•
Using a connector with a pigtail spliced on to the deck leads’ Ethernet pairs has a low
probability of working
. If the deck lead must be terminated to a pigtail, the pigtail length
must be as short as possible, probably no more than 7-8cm. There are no special
considerations for the power conductors other than the connector being able to handle
48VDC and 2 amperes. The drain (shield) wire does not need to be terminated.