Trimble Outdoors SK8 - Manual (Page 181)

Lassen-SK8 Embedded GPS Module E-1
E NMEA 0183
NMEA 0183 is an interface protocol created by the National Marine Electronics
Association. The latest release of NMEA 0183 is Version 2.1 (October 15, 1995). This
protocol was originally established to allow marine navigation equipment to share
information. NMEA 0183 is a simple, yet comprehensive ASCII protocol which defines
both the communication interface and the data format. Since it is a well established
industry standard, NMEA 0183 has also gained popularity for use in applications other
than marine electronics.
For those applications requiring output only from the GPS receiver, NMEA 0183 is a
popular choice since, in many cases, an NMEA 0183 software application code already
exists. The Lassen-SK8 receiver is available with firmware that supports a subset of the
NMEA 0183 messages: GGA and VTG. For a nominal fee, Trimble can offer custom
firmware with a different selection of messages to meet your application requirements.
This appendix provides a brief overview of the NMEA protocol and describes both the
standard and optional messages offered by the Lassen-SK8.
For a complete copy of the NMEA 0183 standard, contact:
NMEA National Office
PO Box 3435
New Bern, NC 28564-3435
U.S.A.
Telephone: +1-919-638-2626
Fax: +1-919-638-4885
E.1 The NMEA 0183 Communication Interface
NMEA 0183 allows a single source (talker) to transmit serial data over a single twisted
wire pair to one or more receivers (listeners). The table below lists the characteristics of
the NMEA 0183 data transmissions.
Table E-1. NMEA 0183 Characteristics
Signal Characteristic NMEA Standard
Baud Rate 4800
Data Bits 8 (d7=0)
Parity None (Disabled)
Stop Bits 1