NMEA Format

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The OEM 719 outputs the data collected after the receiver does it's calculations in the NMEA2000 format by default. NMEA2000 messages are sent as packets that consist of a header followed by (typically) 8 bytes of data. The header for a message specifies the transmitting device, the device to which the message was sent (which may be all devices), the message priority, and the PGN (Parameter Group Number). The PGN indicates which message is being sent, and thus how the data bytes should be interpreted to determine the values of the data fields that the message contains.

Supported NMEA Parameter Group Messages

OEM7 receivers support the following NMEA2000 Parameter Group Messages (PGN) over the CAN bus.

PGN 126992 System Time

The purpose of this PGN is twofold: To provide a regular transmission of UTC time and date. To provide synchronism for measurement data.

PGN 129025 GNSS Position Rapid Update

This PGN provides latitude and longitude referenced to WGS84. Being defined as single frame message, as opposed to other PGNs that include latitude and longitude and are defined as fast or multi-packet, this PGN lends itself to being transmitted more frequently without using up excessive bandwidth on the bus for the benefit of receiving equipment that may require rapid position updates.

PGN 129026 COG & SOG Rapid Update

This PGN is a single frame PGN that provides Course Over Ground (COG) and Speed Over Ground (SOG).

PGN 129027 Position Delta High Precision Rapid Update

The "Position Delta, High Precision Rapid Update" Parameter Group is intended for applications where very high precision and very fast update rates are needed for position data. This PGN can provide delta position changes down to 1 millimeter with a delta time period accurate to 5 milliseconds.

PGN 129029 GNSS Position

This PGN conveys a comprehensive set of Global Navigation Satellite System (GNSS) parameters, including position information.

PGN 129551 GNSS Differential Signal

GNSS differential correction receiver status tagged by sequence ID. Status information includes frequency, SNR, and use as a correction source.

The documents clearly state that the OEM 719 uses the NMEA 2000 standard over the old NMEA 0183. But later refers to versions 3.10 and 4.10 which are versions of the NMEA 0183 standard. It also references “sentences” which I thought existed on NMEA 0183 and older versions, however, I may be mistaken and sentences may be a subsection of PGN’s. Once we receive our first GNSS solution data it should become clear. I have included information on these sentences below.