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.


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: degreesminutes.decimal  2 fixed digits of degrees, 2 fixed digits of mins and a variable number of digits for decimalfraction of minutes. Leading zeros always included for degrees and minutes to maintain fixed length. The decimal point and associated decimalfraction are optional if full resolution is not required 
Longitude 
yyyyy.yy 
Fixed/Variable length field: degreesminutes.decimal  3 fixed digits of degrees, 2 fixed digits of minutes and a variable number of digits for decimalfraction of minutes. Leading zeros always included for degrees and minutes to maintain fixed length. The decimal point and associated decimalfraction are optional if full resolution is not required 
Time 
hhmmss.ss 
Fixed/Variable length field: hoursminutesseconds.decimal  2 fixed digits of hours, 2 fixed digits of minutes, 2 fixed digits of seconds and variable number of digits for decimalfraction of seconds. Leading zeros always included for hours, minutes and seconds to maintain fixed length. The decimal point and associated decimalfraction 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 decimalfraction are optional if full resolution is not required 
Fixed HEX field 
hh___ 
Fixed length HEX numbers only, MSB on the left 
Information Fields 

Variable text 
cc 
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 