Blueprint Subsea seatrac X100 Series, Manual

Page: 130 / 140

SeaTrac Serial Command Interface Reference
Page 130
8.4.6. CID_NAV_REF_POS_UPDATE
The CID_NAV_REF_POS_UPDATE message is generated when the beacon receives acoustic
information sent from another beacon with the
CID_NAV_REF_POS_SEND command.
On reception of the message, the acoustic payload is decoded and the transmitted
Latitude/Longitude position for the specified beacon is output from the serial port.
The connected host system may then use this information to convert previously send NED
coordinates to world coordinates by treading the latitude and longitude as the original of the
NED grid.
This message is a status message that may be sent by the beacon at any time (not in
response to a command message) depending on acoustic activity triggering a
transceiver event.
Response Message Parameters
Parameter Type Description
MSG_ID CID_E Command identification code
(CID_NAV_REF_POS_UPDATE)
ACO_FIX ACOFIX_T A Fix structure containing information relating to
signal from the beacon sending data.
This will not contain range or position information,
but will contain the message SRC_ID.
BEACON_ID BID_E The ID code of the beacon this position refers to.
Valid values are form 1 to 15.
NB: This ID code does not necessarily refer to the
local beacon (although it may).
POSITION_LATITUDE INT32 The latitude part of the sending beacons position,
used as the reference position from which relative
Northing/Easting/Depth positions are based.
This value is encoded in milliseconds of arc angle,
so divide by 3600000 to obtain a value in decimal
degrees.
POSITION_LONGITUDE INT32 The longitude part of the sending beacons position,
used as the reference position from which relative
Northing/Easting/Depth positions are based.
This value is encoded in milliseconds of arc angle,
so divide by 3600000 to obtain a value in decimal
degrees.