Interfaces; Gps 18 Electrical Characteristics; Garmin Interface And Garmin Usb Protocol; Gps 18 Pc, Gps 18 Lvc, & Gps 18-5Hz Protocols - Garmin GPS 18 Technical Specifications

1.5.5

Interfaces

1.5.5.1 GPS 18 Electrical Characteristics

•
GPS 18 USB: USB 2.0 full-speed protocol compatible, as well as USB 1.1 full-speed protocol.
•
GPS 18 PC and LVC: TIA-232-F (RS-232) compatible asynchronous receiver. Default setting is 4800
baud.
•
GPS 18-5Hz: TIA-232-F (RS-232) compatible asynchronous receiver. Default setting is 19200
baud.

1.5.5.2 Garmin Interface and Garmin USB Protocol

Refer to the Garmin Device Interface Specification for information about the Garmin USB Protocol. The
document is located on the Garmin Web site at:
also Appendix B: Binary Phase Output Format
range and carrier phase data from the GPS 18 USB.
Refer to the Garmin Device Interface Specification for details on the Garmin interface. At the time of this
printing, these specs are available from the technical suppport section of our Web site:
http://www.garmin.com/support/commProtocol.html.
1.5.5.3 GPS 18 PC, GPS 18 LVC, & GPS 18-5Hz Protocols
•
NMEA 0183 Version 2.0 or NMEA 0183 Version 2.30 (Version 2.0 is factory default, programmable
by data field 7 of the PGRMC1 sentence described in Section
Information (PGRMC1).
•
Available NMEA 0183 output sentences include GPALM, GPGGA, GPGSA, GPGSV, GPRMC,
GPVTG, GPGLL, PGRME, PGRMF, PGRMT, PGRMV, and PGRMB (Garmin proprietary
sentences). See Section
•
Configuration and initialization is accomplished with NMEA 0183 input sentences. Allows
initialization of information such as expected position, date, time, earth datum, and differential mode.
See Section 4.1 Received NMEA 0183 Sentences
•
Configurable for binary data output including GPS carrier phase data.
1.5.5.4 Measurement Pulse Output (GPS 18 LVC & GPS 18-5Hz only)
•
GPS 18 LVC: 1 Hz pulse with programmable width, configurable in 20 ms increments form 20 ms to
980 ms. See Section 4.1.3 Sensor Configuration Information (PGRMC)
the Measurement Pulse Output (or PPS) feature.
•
GPS 18-5Hz: 5 Hz pulse synchronized with the time of fix. One of the five pulses will align with the
UTC second boundary. The pulse width is programmable from 20 ms to 180 ms. The PGRMC
sentence will indicate which pulse is at the top-of-the-second. See Section
Information (PGRMC)
• 1 µs accuracy for all conditions in which the GPS 18 LVC or GPS 18-5Hz has reported a valid and
accurate position fix for at least the previous 4 seconds.
GPS 18 Technical Specifications (190-00307-00)
http://www.garmin.com/support/commProtocol.html.
for additional information concerning access to raw pseudo-
4.2 Transmitted NMEA 0183 Sentences
for format descriptions.
for details about configuring the Measurement Pulse Output (or PPS) feature.
Page 7
4.1.4 Additional Sensor Configuration
for format descriptions.
for details about configuring
4.1.3 Sensor Configuration
See
Rev. D