TrimTrac ProE Locator, Technical Manual

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TrimTrac ProE Locator Technical Manual v2.0e 137
TrimTrac ProE Defaults
Introduction
Factory default settings of the TrimTrac ProE are listed in Table 90 through Table
94, beginning on page 188. 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 using the Provisioning Module. Please
refer to the TrimTrac Basic State Machine chapter beginning on page 83 for
detailed descriptions of each TrimTrac state.
The TrimTrac ProE 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 ProE and send that almanac
to other TrimTrac ProE units; or
2. The TrimTrac ProE 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 to be collected from the GPS satellites, it is important that when
the TrimTrac ProE 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 ProE 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 ProE. 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 ProE do not match the incoming message, then those
messages are ignored with no response forthcoming from the TrimTrac ProE.
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