User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 75
Position Age
High Priority Alert
(HPA) Flag
“1=Aged” “0=Current”
“0=Normal” Normal Operation
“1=Activated”
Upon initiation of a HPA, the
HPA Status flag is set “1=Activated” and the device
terminates its current operation immediately and transitions to 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 “HPA Report”. Then
the device transitions to the TRANSMIT state and sequences as follows:
a) If the GSM protocol stack confirms that the HPA Report was successfully
sent to the GSM network, then the
HPA 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 HPA Transmit Attempts, N5, prior to the expiration
of the HPA Transmit Timeout, T15. 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 HPA Transmit Timeout, T15, 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(T15),
QUERY(T17) and DELAY(T13) states until:
a) The GSM protocol stack confirms a
HPA 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;
provided, however, HPA Idle
Timeout, T11, and HPA Delay
Timeout, T13, shall apply unless
otherwise instructed by the
server application.
“3=Acknowledged”
Table 17, High Priority Alert Processing