User's Guide

Teletrac, Inc. - Prism TM Information and Installation Guide
26 1622-0300 B1 3/18/04
for Y hours (this message must be set up in Fleet Director as a message for now). Once the
Prism TM has gone to sleep it is unreachable until the operating conditions change or it is time to
wake up. If the unit wakes up and determines that the operating conditions have not changed it
will send out the same message as above.
In order to keep a unit awake, the operating conditions must change. For instance, since the
Prism TM is connected to sense ignition on/off, when the ignition is turned on the unit will wake
up. Another way to keep the unit awake is to keep it busy. By moving the unit into a status that
locates it more frequently than the time required for it to go to sleep, it will remain awake since the
timer is reset after each activity with the unit.
When a unit is out of the coverage area or asleep, it will send messages to the buffer. Once the
messages are in the buffer they are stored until they are downloaded. The unit will still go to
sleep with messages in the buffer. Events or reports that occur while the unit is asleep will still be
stored in the buffer.
When programming the Prism TM, you will have the option to fill in the amount of time the unit
will wait once it has determined that it can go to sleep, how long it will remain asleep and how
long it will stay awake when it does wake up.
Message Store and Forward (Message History)
The unit has ability to store locations, event history and messages. Any of these pieces of data
can be stored while the Prism TM
migrates outside the GPRS coverage area. The unit will first
attempt to send the message or event, if it fails, the message will be sent to a memory buffer for
later delivery. When a report is run, the coverage area will appear greater. With the addition of
storing message, this feature will allow the driver to continue to send status messages while
outside the GPRS coverage area to time stamp his activities so a compliance report can be
generated when he returns to the GPRS coverage area. Also, the messages will be stored even
if the unit goes to sleep.