SeaTrac Serial Command Interface Reference
Page 16
range and the AHRS system can compute the position of the remote beacon in relative real-
world coordinates (Northing, Easting and Depth).
Tracking and navigation systems can be built using one X150 is mounted from the supervisor
vessel, with an application controlling the sequential ‘pinging’ of remote beacons. All relative
positions are computed internally and output the results via serial messages, so no additional
PC hardware is required.
In this mode up to 14 beacons may be tracked with the position of each being optionally
broadcast to others in the network, using the data modem feature.
Alternately, developers may use several X150 beacons fitted to divers or other subsea assets
and establish their own control algorithms to allow create a multiple access network where
each asset can “ping” and obtain positions for every other beacon.
3.7.
Acoustic Protocol Stack
The Acoustic Protocol Stack is connected to the Acoustic Transceiver module and in a fashion
similar to the network and transportation levels of the ISO-OSI network protocol suite,
provides additional beacon functionality through the use of Acoustic Protocols.
For further details on Acoustic Protocols and their command sets, please refer to
section 8 from page 105.
The supported beacon protocols are…
PING
Simple Ping protocol providing the basic ability to query if a beacon is
powered-up and on its response obtain a range and position for it.
ECHO
Testing and diagnostic protocol allowing packets of data to be sent to a
remove beacon and returned back to the sender.
NAV
Navigation protocol, building on the ranging and positioning capabilities
of the beacon to add support for querying remote sensor information,
obtaining enhanced position fixes, and broadcasting beacons positions
to other users of the network.
DAT
Datagram protocol providing commands allowing simple packets of
data to be sent to a remote beacon, and an optional acknowledgment
return made.
From this developers can implement their own data exchange
protocols.
Position and ranging information are available for each
acknowledgment received.
DEX
Data Exchange protocol, building on the DAT protocol but implementing
TCP like data transfer capabilities, including sockets, port numbers,
stream buffering, transmission failure and retry facilities.
