NMEA Standard Logs

Platform:

OEM719, OEM729, OEM7500, OEM7600, OEM7700, OEM7720, PwrPak7, CPT7, CPT7700, SMART7, SMART2

This log contains NMEA logs.

GLMLA	GLONASS Almanac Data
GPALM	Almanac Data
GPGGA	Global Position System Fix Data and Undulation
GPGGALONG	GPS Fix Data, Extra Precision and Undulation
GPGLL	Geographic Position
GPGRS	GPS Range Residuals for Each Satellite
GPGSA	GPS DOP on Active Satellites
GPGST	Estimated Error in Position Solution
GPGSV	GPS Satellites in View
GPHDT	NMEA Heading Log (ALIGN)
GPRMB	Navigation Information
GPRMC	GPS Specific Information
GPVTG	Track Made Good and Ground Speed
GPZDA	UTC Time and Date

The NMEA log structures follow format standards as adopted by the National Marine Electronics Association. The reference document used is "Standard For Interfacing Marine Electronic Devices NMEA 0183 Version 3.01". For further information, refer to www.nmea.org. The following table contains excerpts from Table 6 of the NMEA Standard which defines the variables for the NMEA logs. The actual format for each parameter is indicated after the description.

See the Note in the GPGGA log that applies to all NMEA logs.

Spaces may only be used in variable text fields.
A negative sign "-" (HEX 2D) is the first character in a Field if the value is negative. The sign is omitted if the value is positive.
All data fields are delimited by a comma (,).
Null fields are indicated by no data between two commas (,,). Null fields indicate invalid data or no data available.
The NMEA Standard requires that message length be limited to 82 characters.

Field Type	Symbol	Definition
Special Format Fields
Status	A	Single character field: A = Yes, Data Valid, Warning Flag Clear V = No, Data Invalid, Warning Flag Set
Latitude	llll.ll	Fixed/Variable length field: degrees\|minutes.decimal - 2 fixed digits of degrees, 2 fixed digits of mins and a variable number of digits for decimal-fraction of minutes. Leading zeros always included for degrees and minutes to maintain fixed length. The decimal point and associated decimal-fraction are optional if full resolution is not required
Longitude	yyyyy.yy	Fixed/Variable length field: degrees\|minutes.decimal - 3 fixed digits of degrees, 2 fixed digits of minutes and a variable number of digits for decimal-fraction of minutes. Leading zeros always included for degrees and minutes to maintain fixed length. The decimal point and associated decimal-fraction are optional if full resolution is not required
Time	hhmmss.ss	Fixed/Variable length field: hours\|minutes\|seconds.decimal - 2 fixed digits of hours, 2 fixed digits of minutes, 2 fixed digits of seconds and variable number of digits for decimal-fraction of seconds. Leading zeros always included for hours, minutes and seconds to maintain fixed length. The decimal point and associated decimal-fraction are optional if full resolution is not required.
Defined field		Some fields are specified to contain predefined constants, most often alpha characters. Such a field is indicated in this standard by the presence of one or more valid characters. Excluded from the list of allowable characters are the following which are used to indicate field types within this standard: "A", "a", "c", "hh", "hhmmss.ss", "llll.ll", "x", "yyyyy.yy"
Numeric Value Fields
Variable numbers	x.x	Variable length integer or floating numeric field. Optional leading and trailing zeros. The decimal point and associated decimal-fraction are optional if full resolution is not required (example: 73.10 = 73.1 = 073.1 = 73)
Fixed HEX field	hh___	Fixed length HEX numbers only, MSB on the left
Information Fields
Variable text	c--c	Variable length valid character field
Fixed alpha field	aa___	Fixed length field of uppercase or lowercase alpha characters
Fixed number field	xx___	Fixed length field of numeric characters
Fixed text field	cc___	Fixed length field of valid characters