Xeos Technologies Inc. Petrel User manual

Petrel User Manual
Submersible AIS-Compatible Beacon
Version 0.1
June 2022

Petrel User Manual 0.1 2
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Website
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Version History
Regular checks for the latest manual are suggested. Be sure to check Xeos Technologies’ manuals
page to compare versions and download the latest version.
Version No.
Date
Description
0.1
Jun 2022
Prototype Document

Petrel User Manual 0.1 3
Table of Contents
Preliminary Setup............................................................................................................................ 4
Outside Diagram......................................................................................................................... 4
Physical Connection (Remote Head).......................................................................................... 4
Petrel Operation ............................................................................................................................. 5
Installation.................................................................................................................................. 5
Operational Tips......................................................................................................................... 5
State Diagram............................................................................................................................. 5
Petrel Operating Modes.................................................................................................................. 6
Magnet Turn On/Off .................................................................................................................. 6
Bluetooth Mode ......................................................................................................................... 6
GPS Search Mode....................................................................................................................... 6
AIS Transmit Mode..................................................................................................................... 7
Underwater Mode...................................................................................................................... 8
Using the Magnet Switch................................................................................................................ 9
Water Sensing................................................................................................................................. 9
Bluetooth ........................................................................................................................................ 9
Commands .................................................................................................................................... 10
Settings and Defaults .................................................................................................................... 11
Maintenance................................................................................................................................. 12
Battery Pack ............................................................................................................................. 12
O-Rings ..................................................................................................................................... 13
Electrical Specifications................................................................................................................. 14
Maintenance Specifications.......................................................................................................... 14
Connector Pinout.......................................................................................................................... 15
Petrel Remote Head................................................................................................................. 15
Battery Pack ............................................................................................................................. 15
Warranty, Support and Limited Liability....................................................................................... 16

Petrel User Manual 0.1 4
Preliminary Setup
Outside Diagram
The Petrel has several items of note to help identify a specific device. Shown below are those
identifiers along with key sections.
1
The AIS antenna is screwed into the top of the Petrel and must be added before using
2
The LED of the Petrel is located here. The titanium sections above and below the glass
must be shorted to trigger the water sense
3
The magnet switch for turning the Petrel on and off is located directly below the glass
4
The factory serial number of the Petrel is on the label.
5
A QR code is available to scan to download the manual on the label
6
The meeting point of the electronics head and battery chamber is torqued and should not
be opened. A sealing O-ring is installed here.
7
The bottom endcap is hand-tight for battery replacement. A sealing O-ring is installed here.
Physical Connection (Remote Head)
Pin Number
Name
1
N/C
2
N/C
3
N/C
4
+V Battery
5
N/C
6
Ground
Connector: MCBH-6F-TI, External View

Petrel User Manual 0.1 5
Petrel Operation
Installation
When installing the Petrel there are several factors that can influence performance.
•The Petrel’s head must be pointing directly upward as much as possible.
•GNSS and AIS performance may suffer if large angles of the horizon are blocked, such as if
the Petrel is next to a wall.
•Do not use conductive material at the top of the Petrel around the glass lens; this will cause
the water sensor to fail.
Operational Tips
•Connecting power, or power cycling the device will cause the device to restart from the
beginning of its operational cycle.
•The beacon requires a good view of the sky for any test. It is necessary that any tests be done
outside of a building, far from potential obstructions.
State Diagram
Below is a diagram of the various transitions in the Petrel.

Petrel User Manual 0.1 6
Petrel Operating Modes
Magnet Turn On/Off
The Petrel can be turned off using the magnet turn-off method any time, regardless of its current
state. When the Petrel unit is turned back on by the magnet, it will always start in Bluetooth
mode.
Bluetooth Mode
In this mode, Bluetooth is active and can be connected to with the Xeos Beacon Bluetooth app.
If no Bluetooth connection is made in 5 minutes, the unit will proceed to GPS Search Mode.
However, if a Bluetooth connection is established, the unit will stay in Bluetooth mode until 5
minutes after the most recent Bluetooth session has ended.
If the Petrel unit has exited Bluetooth mode before a Bluetooth connection could be made. The
magnet can be used to turn the unit off and then on again, to re-enter Bluetooth mode.
While in Bluetooth mode, both the AIS and GPS functionality of the unit are inactive. The unit will
not attempt to acquire a GPS lock and will not transmit or receive AIS messages.
GPS Search Mode
In GPS Search Mode, the Petrel unit will attempt to acquire a GPS lock. While in this mode, the
unit’s Bluetooth and AIS functionality are inactive.
If the attempt to acquire a GPS lock is successful, the unit will proceed to AIS Transmit Mode. If
the attempt fails, the unit will proceed to Underwater Mode. The decision to proceed to these
states is made according to the following decision criteria:
•If a GPS lock is obtained, the unit will progress automatically to AIS Transmit Mode.
•If any 90 second period passes without the unit observing a single GPS satellite above a
minimum threshold for signal integrity, the unit proceeds to Underwater Mode.
•If 14 minutes pass without a GPS lock being obtained, the unit proceeds to Underwater
Mode. Note that this 14 minute timeout can be adjusted to be longer or shorter (GPS
Timeout).

Petrel User Manual 0.1 7
AIS Transmit Mode
In AIS Transmit Mode, the Petrel will maintain its GPS lock and activate its AIS functionality to
transmit and receive AIS messages. While in this mode, the unit’s Bluetooth functionality is
inactive.
The Petrel will continuously receive AIS messages and interpret them in order to build an internal
AIS slot map. This slot map is used to avoid slot collisions with other AIS devices when the Petrel
chooses to transmit.
The Petrel will wait at least 1 minute before transmitting to ensure it has fully mapped which AIS
slots are in use. Once this process is complete, it will use its slot map and slot selection algorithm
to find two consecutive free slots. Two slots are required because the Petrel transmits AIS
message type 21, which fills two AIS slots. If at any time the unit is not able to find two
consecutive slots, it will wait for one minute and try again.
A Petrel’s AIS transmissions contain an MMSI and an AIS name. The AIS name is made of up to 20
characters, which can be a combination of uppercase letters (A-Z) or numbers (0-9). The AIS name
can be set by the user. The MMSI is set during the assembly phase and cannot be changed by the
user.
The Petrel AIS slot selection algorithm is designed to prioritize a specific subset of slots based on
the unit’s serial number. This is to avoid potential slot collisions if multiple Petrels are in use in a
localized environment. Each Petrel prioritizes a subset based on its serial number modulus 25. As
an example, Petrels with serial numbers 60 to 84 will all have unique, non-overlapping prioritized
subsets. However, a unit with serial number 85 will prioritize the same subset as serial number
60. If no pair of slots is available in a unit’s prioritized subset, it will expand its search to the full
set of AIS slots.
A Petrel’s first transmission will always be on AIS channel A. It will then proceed to alternate
between channels B and A for successive transmissions.
The Petrel’s AIS system performs various integrity checks at different times to ensure it is
transmitting AIS messages appropriately. If any of these integrity checks fail, the Petrel will
perform a complete reset of its internal AIS system. This may cause the unit’s transmission period
to deviate from the usual 3 minutes, and cause it to perform consecutive channel A
transmissions.

Petrel User Manual 0.1 8
Underwater Mode
While in Underwater Mode, the Petrel will turn off all non-essential functionality and put itself
into a sleep state to minimize power consumption. At regular intervals (every 5 minutes by
default), the Petrel unit will perform a water sense check to determine if it is above water or
submerged. If the check indicates that the unit is above water, it will exit Underwater Mode and
return to GPS Search Mode.
Due to environmental concerns such as biofouling, it is possible for the water sense check to
result in false positives. To combat this problem, the Petrel has a backup counter that
automatically returns the unit to GPS Search Mode when it expires. In the event the unit surfaces,
but cannot sense the lack of water due to biofouling, the unit will still progress to GPS Search
Mode when the backup timer expires. The duration of this timer is user-adjustable by changing
the GPS Timeout setting.
If the backup counter expires while the unit is still underwater, it will transition to GPS Search
Mode while underwater. In this situation, the unit will not be able to receive messages from any
GPS satellites at sufficient signal integrity. It will therefore return to Underwater Mode in
approximately 5 minutes to avoid spending excessive power on GPS searches while underwater.

Petrel User Manual 0.1 9
Using the Magnet Switch
The Petrel beacon is turned ON and OFF using an external magnet near an internal magnetic reed
switch. The reed switch is located just below the glass.
The Petrel will transition between on and off as appropriate when 4 consecutive magnet swipes
occur within 2 seconds of each other. The appropriate color LED will also flash within the glass
when transitioning states with each magnet swipe:
Unit Status Indicators
Action: Turn On
Swipe magnet across switch until LED is solid green
Action: Turn Off
Swipe magnet across switch until LED is solid red
It is important to let all LEDs stop illuminating before initiating any other action.
Water Sensing
The Petrel’s water sensor is used to detect whether it is above water or submerged. The sensor
measured the resistance between the antenna and the electronics head. When the Petrel is
above water, the water sensor is not used. The water sensor will only begin measuring once the
unit enters underwater mode.
The Petrel’s water sense determination is programmatically set to operate optimally in salt water
environments. To operate the device in freshwater, the water sense threshold value may need
to be increased to trigger a water sense surfacing event.
The water sense reading has to be lower than the threshold number when submerged, and higher
than the threshold number when surfaced for surfacing to take place. Freshwater environments
can vary in the reading given. Therefore, testing should be done ahead of freshwater
deployments to ensure proper operation.
Bluetooth
The Petrel has integrated Bluetooth hardware to facilitate local communication with the user for
configuration, flash memory dumps and firmware upgrades via the Xeos Beacon Android App.
The Petrel’s Bluetooth will advertise while in the Bluetooth mode. Bluetooth mode normally lasts
for 5 minutes after the unit is turned on via the magnet. If a Bluetooth connection is established,
the unit will not exit Bluetooth mode until 5 minutes have passed since the last Bluetooth session
ended.

Petrel User Manual 0.1 10
Commands
Below are commands for the Petrel. At this time, commands can only be sent over Bluetooth.
•Each command starts with a dollar sign ($). The Bluetooth app pre-pends this
automatically.
•If a parameter is possible (marked with an X below), that parameter can be an integer to
change the setting, or a question mark (?) to query the current settings.
Command
Description
aisname X
Get the ais name that the unit will use in its AIS messages.
mmsi
Get the MMSI number that the unit will use in its AIS messages.
gpstimeout X
Duration GPS runs before shutting off, in seconds.
wsthresh X
The water/underwater threshold.
wsr
Perform a water sense check. (This command is for testing purposes and
does not cause the unit to change states.)
wsperiod X
The rate of water sense checks while in the underwater mode. Sent as an
integer representing the number of seconds in between water checks.
wsbackper X
The period of backup water checks. Example: If this is set to 5, every fifth
water check will consist of a backup water check.
sn
Show the unit’s production serial number.
rv
Query the unit’s supply voltage. Result is measured in volts.
gpsstats
The unit will display various GPS statistics and metadata.
sleep
The unit will immediately transition to underwater mode.
resetnow
The unit will reset itself. No settings will be changed.
shutdown
Turn off the unit as if it had received magnet swipes.
hdw
Show the unit’s hardware revision.
ver
Show the unit’s current firmware version.
self_test
The unit will run a battery of self tests and display the results.