OpenTracker USB User’s Manual
16
Use PTT Input
– When this checkbox is enabled, the tracker can be connected
inline with a microphone to operate in burst-after-voice (mic encoder) mode. A
packet will be transmitted whenever the microphone PTT is released.
Timeslot
– The timeslot option is typically used to coordinate multiple trackers,
especially for special events where many transmitters will be sharing the same
channel with a high beacon rate. The number entered selects the timeslot’s offset,
in seconds, from the start of the hour. The tracker will transmit at this time, and
every transmit interval after that. The timeslot value should be smaller than the
transmit interval.
As an example, two trackers could be configured with an interval of 10 seconds,
with one tracker set to slot 0 and the other to slot 5. The first tracker would
transmit at 12:00:00, 12:00:10, 12:00:20, and so on, while the second would
transmit at 12:00:05, 12:00:15, and 12:00:20.
Position
– The tracker can operate in GPS or fixed position mode. When
entering a fixed position, enter degrees in the first box and decimal minutes in
the next box. Click on the buttons next to the coordinates to select North/South
and East/West.
Don’t require GPS fix
– Normally, while in GPS mode, the tracker will not
transmit without a valid fix. When this option is selected, the tracker will
continue to transmit its last known position if GPS lock is lost for more than 30
seconds. This condition is indicated by the text ‘NOFIX’ in the status message. If
the tracker has received no valid fix since startup, no position will be reported.
Status text and telemetry packets will be unaffected. This option is particularly
useful for applications like high altitude balloons that may lose GPS lock after
landing, but still need to transmit to be found.