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LA000577C © 2006 Navman New Zealand. All rights reserved. Proprietary information and specications subject to change without notice.
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3.2.1 Adaptive TricklePower mode
In Adaptive TricklePower mode, the processor automatically returns to full power when signal
levels are below the level at which they can be tracked in TricklePower mode. This is the
default behaviour when TricklePower is active. Adaptive TricklePower is always enabled on
the Jupiter 30 and Jupiter 20 S (XTrac), and selectable on the Jupiter 20 standard module.
3.2.2 Push-to-Fix mode
Unlike TricklePower, the operation in this mode is not cyclic. This mode always forces the
GPS software to revert to a continuous sleep mode after a navigation position x. It will
stay in sleep mode until woken by activation of the reset input (Jupiter 20) or wakeup input
(Jupiter 30), and compute a fresh position.
If the ephemeris data becomes invalid or new satellites come into view, the RTC has the
ability to self activate and refresh the data, thus keeping the restart TTFF very short.
This mode yields the lowest power consumption of the module, and is ideal where a battery
powered application requires very few position xes.
For further information on the TricklePower and Push-To-Fix modes refer to the Low Power
Operating Modes application note (LA000513).
3.3 Serial I/O
The module can output serial data in the NMEA format or SiRF Binary format. The serial I/O
protocols are dened in the Navman NMEA reference manual (MN000315) and the SiRF Binary
Protocol reference manual. These describe the format of the serial data from the module, as well
as the structure of the commands. Navman has provided additional functionality to the NMEA
protocol as detailed in the following sections.
3.3.1 Default settings
The default protocol is NMEA, at a baud rate of 9600bps. The frame format is 8 data bits, no
parity bit and 1 stop bit.
The following messages are output by default, at a rate of once per second each:
$GPGGA, $GPGLL, $GPGSA, $GPGSV, $GPRMC, $GPVTG, $GPZDA
All output messages have checksums by default.
Note: message $GPZDA is not available for Jupiter 20 S, or Jupiter 20 D.
3.3.2 NMEA input commands
All NMEA input commands are in the form:
$PSRFxxx,…[*CS] <CR> <LF>
where xxx is a decimal number between 100 and 255 (inclusive).
Note: In each case, CS represents an NMEA checksum, <CR> is carraige return, <LF> is line
feed. These details are covered in the Navman NMEA reference manual MN000315.
Acknowledgements
All input commands other than the standard SiRF commands will be acknowledged with a
sentence of the form:
$PTTK,…*CS
Where the arguments provided to a command are invalid, the response will be the message:
$PTTK,NACK*CS
Checksums
All input commands are accepted whether or not they include a checksum, however if a
checksum is included it must be correct in order for the message to be accepted.
Incorrect checksums will result in the response:
$PTTK,CHECKSUM*CS