User's Manual

Chapter 4 Operation
If the transponder Lat/Lon database is known to be good, then the performance
enhancement feature known as Dynamic Windowing may be enabled. This feature
examines the route transponder density in real time, and adjusts the interrogation window
automatically to allow only the optimum number of transponders into the window at a
given time.
The MMI should typically be used in the GEO mode of interrogation, although there may
be some instances where the FIFO mode may be necessary. In the FIFO mode, the MMI
scans the entire list of transponders in memory, and will attempt to read each unread
transponder one-by-one. If there is a large number of unread transponders in the database,
then this method can become very slow, even becoming ineffective. The FIFO mode
should only be used with a small number of transponders, and with the MMI either
stationary, or moving slowly. The FIFO mode may be used in the unlikely event that
there are problems with the navigation system. In FIFO mode, the vehicle location is not
used, therefore the data from the GPS system is not needed.
While in the Reading mode, various display items are used to provide feedback to the
operator. Using the parameters in the Guide file, or through the System Setup sub-menu,
the option may be selected to display information for each transponder with a good status
as it is processed by the MMI. Along with this option, the MMI can be directed to beep
with each good read. If desired, all display options may be turned off, or any combination
of options may be turned on.
The MMI may be placed in the Command mode at any time during operation. While in
the Command mode, the polling of transponders in the route is suspended. During the
execution of a particular route, the operator may change any of the System Setup
parameters as needed. The altering of the various parameters will not affect any of the
data in the route, but improper settings may adversely affect the performance of the MMI.
In the event that the System Setup parameters have been altered, and the original settings
are unknown, the operator may use the Break option, to halt the MMI. The MMI may
then be re-powered, and the default Guide file settings will be restored, and the prior
progress of the route will resume from the point where the Break option was used.
If the MMI is inadvertently turned off before a proper exit is accomplished, the current
route data will still be saved in backup memory. When the MMI is turned on again, the
route will continue from the point where it was at before it was turned off. The MMI may
be anywhere along the route when power is restored.
The vehicle position is constantly calculated and updated by the GPS navigation system.
The current vehicle position is used with the Lat/Lon or GEO mode of interrogation to
determine which transponders are within range of the vehicle, and may therefore be
interrogated. The current vehicle position is also used with either interrogation mode to
mark the Lat/Lon coordinates at the moment a good read takes place. The resulting
position data is stored with the other data for the transponder that responded. The mode
of interrogation may be changed at any time during the reading mode by pressing the