User's Manual

DRAFT TrimTrac 1.5 Technical Manual v0.3ab 102
TrimTrac 1.5 Defaults
Introduction
Factory default settings of the TrimTrac 1.5 are listed in Table 82 through Table
86, beginning on page 147. All such default settings can be easily changed to suit
the particular application requirements. The challenge for most is figuring out the
true applications requirements.
While most of the settings can be configured or changed by sending the
appropriate commands over the GSM network, non-default entries for certain
fields such as the Unit Identification number (Unit ID), Security Password and
SIM PIN can only be entered or changed while the device is connected to a PC
using the Provisioning Module. Please refer to the TrimTrac State Machine
chapter beginning on page 52 for detailed descriptions of each TrimTrac state.
The TrimTrac 1.5 comes from the factory with no time set and with no GPS
almanac or location stored in memory. The time and location is set once the
device has achieved its first position fix. A GPS Almanac can be loaded in either
of two ways:
1. Use the Windows PC-based TrimTrac GPS Almanac Tool to retrieve a
current almanac from an operational TrimTrac 1.5 and send that almanac
to other TrimTrac 1.5s; or
2. The TrimTrac 1.5 will download a complete current almanac from the
GPS satellites after it has computed its first fix. Collection of the almanac
will occur in the background and will not delay or otherwise interfere with
other operations, such as transmitting or receiving over-the-air messages.
If an almanac is collected from the GPS satellites, it is important that when the
TrimTrac 1.5 is first activated that it be given a clear view of the sky with
sufficient time to calculate its first position fix and to collect a full almanac.
Security Considerations
Communication Security
To maintain the security of the TrimTrac 1.5 it will only accept an incoming
TrimTrac Application message if the Unit ID and Security Password in the
message match those contained in the TrimTrac 1.5. The message must also
include a correct Checksum value. This will ensure that only the authorized
server application is able to change the device configuration. If any of these
fields in the TrimTrac 1.5 do not match the incoming message, then those
messages are ignored with no response forthcoming from the TrimTrac 1.5.
The SIM PIN is a feature of GSM SIMs that allows the owner of the SIM to put a
lock on the SIM. In order to use the account associated with the SIM, the user of
the GSM device must provide the SIM PIN after SIM insertion or device power