Chapter 6. Deck unit and surface dunker
6.1 Deck unit block diagram
The core of the deck unit is a Single Board Computer, powered by a large lithium ion battery pack capable of supporting deck operations for multiple hours to days, depending on usage. The computer has two LAN interfaces. One is dedicated to the Aquarius connection and has a DHCP server available that will provide to the OBS an I.P. address. A PoE injector allows to provide power to the Aquarius from the deck unit on the same Ethernet port. This will also be used to reboot the LPC in normal power mode, with the LAN interface on. The other LAN interface is dedicated to connections to the external world.
A PTP server is installed inside the deck unit for time synchronization of the Aquarius prior to deployments.
The SBC is also connected to the ULPD and LPC serial consoles and drives the surface acoustic dunker using other two RS-232 connections, one for the Command line of the modem, one for the Data line of the modem.
The deck unit is waterproof and having a large battery pack allows to work on deck, also in rough conditions, without the use of any mains, increasing the safety of the operators.
6.2 Side connectors panel
The deck unit right panel contains all the connectors arranged as below
Starting from the left, the connector functions are:
Power in: input voltage 90 to 305 V AC at 43 to 63 Hertz
GPS Antenna: an RF input for the GNSS receiver which synchronises the built-in PTP server
Dunker: this connection provides two serial links to the acoustic Dunker
Aquarius Ethernet: Ethernet cable to Aquarius. PoE can be turned on and off only on this port.
Aquarius RS-232: serial connections to the Aquarius ULPD and LPC consoles.
Ethernet: connection to external LAN.
6.3 Connect to the ULPD and to the LPC consoles
Connect a computer or the Güralp deck unit to the Aquarius Ethernet and RS-232 connector (see Section 12.2) using the provided cable.
A connection is then made using a terminal emulator, such as minicom under Linux or PuTTY under Windows. The appropriate COM/USB port should be entered as the "Serial line", and the "Speed" should be set to 115200 Baud.
Two COM/USB ports are used, one to connect to the ULPD console and one to the LPC.
