User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 17
Fix Rate
In its default configuration, the TrimTrac 1.5 will compute a new position fix each
time the device cycles through the FIX State. Certain applications may, however,
benefit from having more continuous GPS fixes available, in which case, the GPS
receiver can be configured to operate at 1 Hz. Operating the GPS receiver at 1 Hz
enables more real time geofence enforcement. Also, if 1 Hz GPS is enabled and the
device comes to rest in an area where it can not get a final at-rest position fix, then
the TrimTrac 1.5 report its last known GPS fix based on the 1 Hz rate. The GPS Fix
Rate set by using either the AT+CTKZ command or by sending the TrimTrac 1.5 a
SET_EXT2_APP_CONFIG message.
Log Rate
Every time the TrimTrac 1.5 cycles through the standard State Machine due to
motion the TrimTrac log its current position (or position fix attempt). This logging
rate is determined primarily by DELAY State Timeout, T4.
Report Rate
This refers to how many of the logged positions get transmitted. The default is every
logged message gets transmitted. It may be useful, in some applications, to transmit
only every other or every X logged message. This saves recurring communication
costs but gives a denser historical log of previous positions should the desire to query
such logged positions arise. For instance, it may be useful in historical analysis of
route adherence on an exception basis.
The reporting frequency is determined by the Report Delay Flag. If set to “5”, then
the TrimTrac 1.5 will log five motion triggered messages, either POSITION_REP
and/or STATUS_MESSAGE, and then report the next one. The five logged message
remain available for subsequent download should the need arise, but on an ongoing,
normal basis, they will not be transmitted. Setting the Report Delay Flag to”6” will
cause the TrimTrac 1.5 to log ten messages and then transmit the next.
Parameter Settings Msg. Header
(See Page)
Commands
( See Page)
DELAY Timeout,
T4
In seconds (10 – 86400)
Report Delay Flag
5=Log 5 messages, transmit next;
6=Log 10 messages, transmit next
>STKA(113)
>QTKA(123)
>RTKA(130)
AT+CTKC
(83)
GPS Fix Rate 0=GPS operation during FIX
State only; 1=1Hz GPS
operation except while
stationary
>STKZ(116)
>RTKZ (133)
>QTKZ(123)
AT+CTKZ
(99)
Table 5. Fix, Log and Reporting Rate Parameters, Settings, Messages and Commands