LA010812A © 2007 Navman Wireless. All rights reserved. Proprietary information and specifications subject to change without notice.
5.0 Data communications
5.1 Serial communications
The host serial I/O of the receiver serial data interface supports full duplex communications
between the receiver and the user. The default serial modes are shown below:
5.2 Default baud rate and port assignments
Port
J21 (GSW2)
J21S (GSW2)
J31 (GSW3)
Port.A
NMEA, 4800
NMEA, 4800
NMEA, 4800
Port B
DGPS, 9600
SiRF Binary, 38400
SiRF binary, 38 400*
While these are the default baud rates, they can be changed using the “write-to-flash” feature. Refer to the
Application note for WTF.
Table 5-1: Default baud rate and port assignment comparison
6.0 Software
6.1 Software functionality
Feature
Description
J20/20S
J31
DGPS
Accepts DGPS corrections in the RTCM SC-104
format
Yes
No
PPS time
message
PPS binary output message, MID52 (0 x 34)
Yes
No *
SBAS
message
SBAS operating parameters binary output
message, MID50 (0x32)
Yes
No.
†
User GPIO
Proprietary NMEA messaging control User GPIO
Yes
No
GPS Fix
GPS fix indication, active low, Pin 20
Yes
No
Wake Up
Push to Fix Power management wake up on
positive going edge, Pin 20
No
Yes
* Planned implementation for later version of code; † See alternate MID 10
Table 6-1: Software functionality comparison
NOTE:
Reset Push to Fix mode function not compatible. Wake up line PIN20 must be used for
PTF MODE on J31.
6.1.1 Navigation settings
The J31 with its default navigation settings will outperform the J21/21S units with their default
navigation settings. Therefore any input messages issued to J21 units for Navigation settings
should be initially disabled until the performance is compared.
The J31 supports Config to Flash and User Profiles for advanced functionality not supported on
the J21/21S. These settings can be set in production or by the user firmware.
6.1.2 1PPS pulse width
The 1PPS is far more accurate in the J31 but the pulse width is narrower at 1uS.
Note: The Binary 1PPS message Message ID 52 is not currently supported by the J31.
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
