Maretron GPS100 - Manual (Page 24)

GPS100 User’s Manual
Page A8 Appendix A – NMEA 2000 ® Interfacing Revision 1.2
2: Commanded PGN (24 bits) – set this field’s value to 126720 decimal (0x1EF00
hexadecimal), which denotes the Maretron proprietary PGN
3: Priority Setting (4 bits) – set this field’s value to 0x8, which indicates to leave priority
settings unchanged
4: Reserved (4 bits) – set this field’s value to 0xF, which is the value for a reserved field
of this size
5: Number of Pairs of Commanded Parameters to Follow (8 bits) – set this field’s value
to 0x4, indicating that four parameters will follow
6: Number of First Commanded Parameter (8 bits) – set this field’s value to 0x1
7: Maretron Vendor ID and Industry Code (16 bits) – set this field to 0x9889, which is a
combination of Maretron’s vendor ID and the marine industry code
8: Number of Second Commanded Parameter (8 bits) – set this field’s value to 0x02
9: Product Code (16 bits) – set this field’s value to 0x6F0, which is the NMEA 2000 ®
product code for the GPS100.
10: Number of Third Commanded Parameter (8 bits) – set this field’s value to 0x03
11: Software Code (16 bits) – set this field’s value to 0x0001, which is the identifier for
this version of the Maretron proprietary protocol
12: Maretron Command (8 bits) – set this field’s value to 0x33, which will change the
SBAS parameter as selected by the following fields.
13: SBAS parameter (24 bits) – this field includes 3 parameters:
23 16 15 8 7 0
Timeout FlgBits PRN
Timeout: Maximum age in seconds (1-250) of differential corrections (factory
default=18). A value of 0 will restore the timeout values to the factory
default value.
FlgBits: Status of SBAS operation (default=0x00)
Bit 0: SBAS Timeout: 0 = default, 1 = user. If this field is set to 0, then
the default value of 18 seconds is used. If this field is set to 1,
then the value of the Timeout field is used.
Bit 1: Reserved. This field should always be programmed to 0.
Bit 2: Reserved. This field should always be programmed to 0.
Bit 3: SBAS PRN: 0 = AutoScan; 1 = Manual (user). If this field is set
to 0, then the GPS100 will use the SBAS satellite with the
strongest signal. If this field is set to 1, then the GPS100 will
only use the SBAS satellite whose PRN is programmed into the
PRN field.
Bit 4: Reserved. This field should always be programmed to 0.
PRN: This causes the GPS to use a particular SBAS satellite by specifying the
PRN of the desired SBAS satellite if Bit 3 of FlgBits = 1. A programmed
value of 0 for the PRN will force the GPS to auto scan (factory default)
while programmed values of 120-138 use the SBAS satellite with the
corresponding PRN.