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Drivers Manual

Network - NMEA Position (LLQ) - 12


Driver decodes the $--LLQ message, containing position and quality information. Also decodes standard $GPGGA messages.
Two versions of the driver are available: a Serial version and a Network version (UDP).

The internal working of the drivers are the same except for the data reception.

Driver Information

Driver NMEA Position Interface Type Serial/UDP/TCP-IP Driver Class Type Terminated
UTC Driver (question) Yes and No

Input / Output Input (two-way)  Executable DrvNMEA0183UDP.exe
Related Systems
Related Pages  

Decoding Notes

If an incoming string contains a zero time (00:00:00) and the coordinate fields are also zero then the string is not decoded. This was done to prevent faulty positions from entering the system.

The driver converts the grid coordinates from the LLQ to geographical coordinates. The checksum from this message is not used in this driver.
The decoding of the GPGGA message is a bit different than usual: Instead of rejecting a complete message when the age of differential GPS data and differential reference station id are missing the rest of the message will still be used.

Database Setup

To use this driver create a new system. Choose Position Navigation System and browse for NMEA Position ($--LLQ) or NMEA Position (GPGGA).

Drivers IO Notes

The options have no effect on the LLQ message decoding.

The NOCS makes the driver ignore the checksum of the GPGGA.

MSL gets the altitude from the message and adds the geoidal separation before storing it in the Database.

ELL Stores the height on the ellipsoid.