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A-BUOY prototype

Acoustic Buoy with 2.4GHz wlan, GSM remote control and GPS position transponder;
here afterwards "A-BUOY"(development 2008).
The A-BUOY is an underwater acoustic recorder based on the following hardware and software:
- one Sensor Technology SQ26 preamplified hydrophone. with 30m of cable;
- one FIT-PC low power computer, industrial version, with 256GB Solid State Disk, dual ethernet interface, integrated audio interface, Total-recorder audio recording software, UltraVNC remote desktop software, HDMI video interface, usb keyboard and mouse;
- one HSPDA-UMTS router Teltonika RT106 with ethernet interface and wi-fi features;
- one 2.4GHz Ubiquity network Bullet M2 hiperlan module with 6dB gain omnidirectional antenna, configured as an access point;
- one GSM remote control Teltonika TWCT22;
- one position transponder Teltonika FM1100 GPS / GSM tracker with External GPS and GSM antennas;



This is a widely used transducer with large frequency band and simple use.
It has been


One of the features of this unit is that it automatically turns on when powered. This allows the remote user to turn the system on and off sending SMS commands to the remote control of the buoy.
The FIT-PC2 industrial version, is a low power compact computer, with dual ethernet interface, integrated wlan, HDMI video interface etc.
General features are described here:
and full specifications are here:
Some basic software has been installed in order to deliver scheduled recordings. TotalRecorder is licensed on this unit and gives flexible recording schedule.
We have also included an UltraVNC remote desktop server installation, with file transfer capability.
The computer has a 256GB Solid State Disk, fast and reliable in extreme working conditions.
The computer has two ethernet addresses:

the VNC server password is

Remote control

The remote control uses the standard power supply of the buoy at 12V.
The batteries must be recharged and connected to the remote control in order to operate.

Tests can be made using, while at the laboratory, the provided 4pin circular powering cable and a standard 12VDC @ 3A power supply.
The Teltonika TWCT22 GSM remote control is described here:

The programming software is here:
TWCT22 programming software
the software runs on MSWindows, and requires a COM: port (RS232) to connect the TWCT22 to the programming computer via the provided cable and the front port on the control unit.
There is no direct connection from this unit to the rest of the equipment other than the 4 switchable channels.
The remote control needs a valid GSM SIM card, and the relative phone number, to correctly operate.
PIN code of the SIM card must be disabled to easily operate and configure the system.
The SIM card must have valid credit available and must be able to send and receive SMS - text messages.
4 - FOUR - outputs can be controlled by this unit.
The devices connected to the outputs are:
1 - FIT-PC
2 - 3G-HSPDA router
3 - WLAN - external interface, UBIQUITY Bullet M2 radio
4 - GPS/GSM position transponder

The same effects of powering the single parts can be obtained when testing using the provided 5 PIN circular connector.
PIN assignment is the same as above, with PIN 5 as COMMON GROUND.

Position transponder

The position transponder needs a valid GSM SIM card, and the relative phone number, to correctly operate.
PIN code of the SIM card must be disabled to easily operate and configure the system.
The SIM card must have valid credit available and must be able to send and receive SMS - text messages and make a GPRS connection to the remote server.
The GSM GPS transponder used in these units is the Teltonika FM1100 described here:

General manual is here:

Complete installation software package, including usb drivers, is here:
The unit is a vehicle locator, featuring a GPS and a GSM engine, together with real-time tracking capabilities using a DATA connection via GPRS.

The system needs a registration to a third part server. We can provide a lifetime registration included in this system (we need to have from the customer some parameters of the unit, including the phone number of the SIM card that has been inserted), or you can use one service like this:


A 3G HSPDA router is installed in this unit.
This device acts as a DHCHP server also, even if all parts have a fixed IP address.
This router also has a WLAN access point that is currently disabled and that be enable via configuration.
The IP address of this unit is;
the username is "admin";
the password is "admin01"
as reported on the sticker on the unit.
Router manual is HERE:
User manual
while quick start guide is HERE:
Quick Start Guide


This unit has been arranged in a three 50cm segment UV-stabilized thick-wall PVC canister suitable for pressures up to 16ATM.

There are three segments:

- one bottom segment with batteries,

- one middle segment with the FIT-PCi computer, the GSM remote control, the HSPDA router and the hydrophone (cable with resinated wall pass-through),

- one top segment, with mostly antennas (one long external white wlan antenna, directly connected to the Ubiquity Bullet M2 unit, one GPS external antenna (resinated at the top), one GSM antenna for the remote control, two GSM antennas for the HSPDA router.

We can provide extra canisters of any of the three.
The cable outside is 30m long and can be kept rolled if required sensor depth is shallower than -30m.
Each cap must be sealed with the provided gasket (black flat rubber gasket).
Each cap must be sealed with FOUR STAINLESS STEEL screws and their relative eight washers. All screws are provided.
Screws must be positioned and gently turned by hand in opposite pairs.
All screws must be tightened with the provided tools.


Four battery packs, each made of 10 size "D" NiMH rechargeable cells with 10A capacity are assembled in the bottom canister.
There is plenty of space to host different powering solutions, but final weight of the system must be a concern.
The battery packs are totally independent and featured with a 5A fuse each. The must be recharged using the 4pin "molex" type connector using the provided multi-purpose battery charger. The battery charger must be powered using a 12VDC source connected via the car-type connector.
Do not exceed the 4A current, regulated via the front knob on the recharger.

Procedures (currently being integrated):


Get familiar with the computer and software!

Connect a standard HDMI monitor and the provided keyboard and mouse.
Power the system using the provided 5 pin circular plug connected to a 12VDC power source.

You can power the systems independently using a 12VDC power supply RED is positive:
PIN 2: 3G router
PIN 3: High Power WLAN Ubiquity hiperlan interface
PIN 4: GPS/GSM position transponder


Use a GSM SIM with the PIN set as DISABLED.
To disable the PIN request you can use a standard phone and disable the PIN request using the phone menu (usually somewhere in the menu).
Get familiar with the GSM remote control!
The remote control requires a GSM SIM card, able to send and receive SMS - text messages.
The GSM requires to be powered in order to be programmed. You can provide power via the 12V battery or via an external power supply.
The GSM remote also requires some programming:
- download and install the programming software;
- use a computer with an RS232 serial port and connect the provided cable to the computer port and the GSM remote (the cable has a standard serial port at one end and and RJ45 plug at the other end, connect the RJ45 to the port on the front of the GSM remote);
- start the programming software;
- set the correct date and time, but always consider that the timer will stop when the battery will be disconnected (there is no internal backup battery);
- decide the users that will be able to send and receive commands;
- program their names and numbers in the unit, as USER, and create GROUPS according to equivalent user levels.
- program the actions and logics
- CONSIDER the connection scheme:
route 1 will control the computer;
route 2 will control the 3G router;
route 3 will control the wlan system connected to the second ehternet of the computer;
route 4 will control the GSM/GPS transponder.
A second UBIQUITY Bullet M2 WLAN interface and a panel high-gain antenna
have been provided in order to link the buoy to the coast over distances in the order of kilometers.
The unit must be powered via the provided power supply or via a non standard Power-over-Ethernet termination: pairs 4-5 positive, pairs 7-8 negative, 12..24VDC.
A rough estimation of possible link distances, considering the gain of the two involved antennas (6dB for the stick and 15dB for the panel antennas), the output power of the transceivers, and the cable insertion loss (near to zero), returns a value in the order of 3-4 km. This value must be carefully checked and tested in the field as it may suffer propagation issues depending on the correct alignment and the buoy antenna movement.
As the buoy wlan transceiver is configured as an access point, in the standard 2.4GHz band, you will be able to connect s a client with any standard wi-fi device.


Use a GSM SIM with the PIN set as DISABLED.
To disable the PIN request you can use a standard phone and disable the PIN request using the phone menu (usually somewhere in the menu).
Get familiar with the position transponder!
The transponder needs some configuration that must be done using the software provided here:

Software package, including usb drivers, is at:

Manual is at:

You will learn that you will be able to configure the system in order to report the position every xx minutes, or when exiting a defined area.


Get familiar with the canister!
The canister is made of a UV stabilized Thick-wall PVC pipe, terminated with a standard gasket, a cap, its screws and gaskets.

All parts are rather standard in hydraulic warehouses and it should be easy to find spares and optional parts anywhere in Europe.
Please mind that if the unit is submerged the GSM and WLAN networks can not communicate with the devices. This unit can receive remote commands only when at surface.

The canister is made to be stable in the water with the antennas at the top and the battery segment at the bottom. An extra flotation foam is installed at the middle element, to give some extra stability. This foam is protected using a net, also used to keep the hydrophone cable in position.
The internal canister of the middle element has a limited position, and a fixed ring is used to protect the hydrophone cable from being pinched by the internal canister with the computer and router.
Always be sure to tighten the screws (first by hand then using the tools) on the gasket using the same sequence used when changing the car tires: screw 1, screw 3, screw 2 and then screw 4.

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