Rainbow Electronics EB-A801 - Manual (Page 12)

EB-A801 User’s Manual V1.0
EverMore Technology Inc.
2F, No.7, R&D Road 1, Science-Based Industrial Park, Hsinchu, Taiwan, 300, R.O.C.
http://www.emt.com.tw
12
5. Software Specification
5.1 EB-A801 NMEA-0183 Output Message
Description
GGA (Default) Global positioning system fixed data
GLL (Default) Geographic position - latitude/longitude
GSA (Default) GNSS DOP and active satellites
GSV (Default) GNSS satellites in view
RMC (Default) Recommended minimum specific GNSS data
VTG (Default) Course over ground and ground speed
Table 1 NMEA-0183 Output Messages
5.2 General NMEA Format
The general NMEA format consists of an ASCII string commencing with a ‘$’ character and
terminating with a <CR><LF> sequence. NMEA standard messages commence with ‘GP’ then a
3-letter message identifier. The message header is followed by a comma delimited list of fields
optionally terminated with a checksum consisting of an asterix ‘*’ and a 2 digit hex value representing
the checksum. There is no comma preceding the checksum field. When present, the checksum is
calculated as a bitwise exclusive of the characters between the ‘$’ and ‘*’. As an ASCII representation,
the number of digits in each number will vary depending on the number and precision, hence the
record length will vary. Certain fields may be omitted if they are not used, in which case the field
position is reserved using commas to ensure correct interpretation of subsequent fields.
The tables below indicate the maximum and minimum widths of the fields to allow for buffer size
allocation.