User manual

MPTP | MPTP commands 13
Telematics Terminal.
If for some reason messages which have exclamation and/or question mark as
first character do not work in some network, there is a possibility to change the
header characters. It is recommended though that the header characters are
changed only if the default ones do not work. Note also that if the header
characters are changed it should be done to all the terminals which are
connected to the same system.
There is a setting by which the header characters can be changed. Note that
the question and exclamation mark should not be interchanged.
In this example, the sender’s role is Mobile Telematics Terminal (!). The
command is a tracking update (TRG).
01/01
Part number
Sometimes, the MPTP command may need to be sent in several parts. The
part number consists of the part number of the message, a slash character,
and the total number of parts which make up the complete command. Please
refer to Reassembling a received MPTP command (3.3) for more information
on reassembling a message received in several parts.
Many commands omit this field altogether as they are always sent in one part.
In this example, the message consists of one part.
The two fields which follow are specific to the !TRG command. Having identified the
command as !TRG, the instrument which receives the message can interpret the fields as
Trigger type with value “4”, and Service state with value “1”. These values indicate that the
event, which triggered the sending of the tracking update command, was exceeding a
speed limit. The command then continues with common fields, as follows.
norm
Mode
A four-character string identifying the mode the instrument is in: norm for
normal mode, emer for emergency mode, and test for testing mode. Only
selected commands ever use modes other than norm.
In this example, the instrument is in normal mode.
075%
Battery level
Three digits and a percentage character, indicating the battery level of the
instrument.
The battery voltage can also be sent as millivolts. This is doen by sending 4
number code e.g. 3897 = 3.897V
In this example, 75% of battery charge is left.
gps
Position source
A three-character string identifying the source of the position in the message
(cf. below):
gps for GPS. Position is aquired from GPS and the timestamp is related to
actual aquisaition time