User manual

MPTP | MPTP commands 14
gpa, position is aquired from GPS, but the timestamp is updated, since no
movement is detected with motion sensor after last actual position fix. Note the
motion sensor parameters, that define the needed movement.
gpb position is aquired from GPS, but the timestamp is NOT updated, since
movement is detected with motion sensor but not calculated by gps. Note the
motion sensor parameters, that define the needed movement.
net for GSM network.
Most commands always assume GPS to be the position source.
In this example, the position has been acquired from the GPS receiver with
valid fix from receiver. It is stored as coordinates in the Position field.
1
Position format
A digit indicating the position format in which the position information in the
message is given: 1 for WGS-84, and 2 for WGS-84 with precision.
If the position format is 2 (WGS-84 with precision) a field named Position
precision will be located after the Position field. Otherwise it will not be present
at all, this means that also the underscore characters are missing.
!GNR and !EGN always use position format 1 regardless of the value of the
setting. Position format 2 (WGS-84 with precision) is not used with !GNR and !
EGN because of lack of space in one SMS.
Note that position format 2 is supported only by Track NT versions of the
terminals.
If the position format is 3 (WGS84 with SRD beacon data) datafield in the end
of the message will contain information on surrounding SRD Beacons.
N68.28.43,9_
E027.27.02,4
Position
Instrument’s last known position at the time of sending of the message. It’s
contents depend on the Position source:
If the position source is gps, this field contains the coordinates of the
position. The Position format field determines the format used for them.
For WGS-84, latitude and longitude are given in degrees, minutes,
seconds and fractions of seconds, with a letter indicating the hemisphere
(N, S, W, E) preceding the numbers. A single field separator character (_)
separates the latitude and the longitude sub-fields.
Currently, TWIG instruments do not support position formats other than
WGS-84.
If the position source is net, this field is replaced by another one containing
network measurement data, which can be used to roughly determine the
instrument’s position.
In this example, the latitude and longitude of the last known position are N
68°28’43.9” and E 027°27’02.4”, respectively.
37 Position precision