Second NMEA Messages
Applicable to: UM621 series
The message is applicable to the integrated products to output the GNSS positioning results only. It has a format of adding a TAG BLOCK \s:1*78\ before the standard NMEA sentences. Take outputting GGA as an example, the second output format is:
\s:178\$-GGA,time,Lat,N,Lon,E,FS,NoSV,HDOP,msl,M,Altref,M,DiffAge,DiffStationcs\r\n
TAG BLOCK Description
| Parameter | Format | Description |
|---|---|---|
| tagStart | STR | TAG BLOCK start character; specified to constant ’\’ |
| parameter-code | STR | Parameter code; specified to constant ’s:’ meaning source identification |
| value | UINT | Parameter value; specified to constant 1 meaning the second output |
| tagCs | U8 | Checksum; two hexadecimal characters obtained by calculating an XOR of all characters between but not including the ‘\' and ‘*' in the TAG BLOCK |
| tagEnd | STR | TAG BLOCK end character; specified to constant ’\’ |
To enable the second NMEA output, you need to configure the mode to 2 - Vehicle-mounted mode (dual-engine) in the message CFGINS. See section CFGINS for more information.