User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 77
Position Age
Low Priority Alert
(LPA) Flag
“1=Aged” “0=Current”
“0=Normal” Normal Operation
“1=Activated”
Upon motion and initiation of a LPA, the
LPA Status flag is set “1=Activated”
and the device terminates its current operation immediately, unless in the FIX or
TRANSMIT states, and transitions to STATUS state. If in the FIX or TRANSMIT
state, then those states are completed prior to transitioning to the STATUS state.
While in the STATUS state, the devices generates a new STATUS_MESSAGE in
which the TriggerType is set “2=Alert”. This STATUS_MESSAGE is combined
with most recent logged POSITION_REPORT, collectively “LPA Report”. Then
the device transitions to the TRANSMIT state and sequences as follows:
a) If the GSM protocol stack confirms that the LPA Report was successfully
sent to the GSM network, then the
LPA Status flag is changed from
“1=Activated” to “2=Sent” and the unit will transition to the QUERY state;
OR
b) The device will make LPA Transmit Attempts, N7, prior to the expiration
of the TRANSMIT Timeout, T3. A new transmit attempt will be initiated
each time the GSM protocol stack confirms the attempted transmission
failed or if connection to the GSM is lost. Upon termination of the current
TRANSMIT state, the device will transition to the DELAY state; OR
c) If a connection to a GSM network has not been established prior to
expiration of TRANSMIT Timeout, T3, then the current TRANSMIT state
will be terminated and transition to the DELAY State.
“2=Sent”
Regardless of motion, cycle continuously
through FIX, STATUS, TRANSMIT(T3),
QUERY(T5) and DELAY(T4) states until:
a) The GSM protocol stack confirms a
LPA Report containing a new position
fix is successfully sent; OR
b) A sequence altering message command
is received during the QUERY state.
Operate in accordance with the
standard State machine unless
otherwise instructed by the
server application.
“3=Acknowledged”
Table 19, Low Priority Alert Processing