NMEA Receiver

The NMEA Receiver module receives the position records such as NMEA positions from the connected station and, in baseline mode, uses them to compute a vector from a selected base station to the connected station. It makes the data available to other modules, such as the NMEA Engine, raw storage and routing modules.

Input data

Many modern receiver brands send out their data not only in a receiver-specific data format that needs a specific decoder. They often can process their position and broadcast them in the receiver-independent NMEA format, either as GGA or as GGK records.

In a monitoring approach, the module receives the positions as an RTPD data stream from a connected RTPD Server. In this case, the incoming positions are considered to be absolute positions of the selected station.

Adding the module

When the module is first being added, the NMEA Receiver Properties dialog appears. It lets you define and select NMEA Receiver module configurations. Each configuration specifies the following:

The connection to the instrument (the receiver sending NMEA records),
Station information for this station and the base station used as origin of the resulting vector.
Is filtering enabled?

Status of the NMEA Receiver module

In the Tree view, each NMEA Receiver module is represented by its configuration name and a status-identifying icon.

	Connected and receiving data.
	Alarm status: No data from the NMEA Receiver.

For more information, the module displays the NMEA Receiver Status module-view page.

Alarming

With alarming activated, the NMEA Receiver module triggers alarms, if one of the following happens:

Fix lost (at least one epoch arrived for which the status is "not fixed")
No data from NMEA Receiver

Dependent modules

Router

Logging into the database

All connection events are logged into the central database. The database contains the following tables, which can be filled in by several modules types:

Table name	Contents	More information
DriverConnections	Settings and events of incoming and outgoing connections.	One row for each module and each period it is connected.
DataOutages	Periods of missing data.	One row for each event. Logging into the database starts after a module-depending minimum data outage period.