The Lassen iQ GPS receiver operates using one of three protocols Trimble Standard Interface Protocol (TSIP), Trimble ASCII Interface Protocol (TAIP), or NMEA 0183. Protocol selection and port characteristics are user configurables. The factory default settings are:
• Port 1, TSIP bi-directional
• Port 2, NMEA 0183 OUT/RTCM SC-104 V2.1 IN
TSIP is a powerful binary packet protocol that allows the system designer maximum configuration control over the GPS receiver for optimum performance in any number of applications. TSIP supports over 20 commands and their associated response packets for use in configuring the Lassen iQ GPS receiver to meet user requirements.
TAIP is the Trimble ASCII interface protocol designed specifically for vehicle tracking applications. It is a bi-directional protocol using simple ASCII commands with the associated ASCII responses.
NMEA 0183 is an industry standard protocol common to marine applications. NMEA provides direct compatibility with other NMEAcapable devices such as chart plotters, radars, etc. The Lassen iQ GPS receiver supports most NMEA messages for GPS navigation. NMEA messages and output rates can be user selected as required.
The Lassen iQ GPS receiver can be configured for RTCM SC-104 input which is the GPS industry standard for differential correction data. The receive side of Port 2 is factory configured to accept RTCM data.
Above all protocols the NMEA protocol is the standard protocol for all GPS. More about NMEA protocol is given below
NMEA SENTENCE TYPES
The following information describes the most common NMEA-0183 sentences transmitted by GPS receivers. The NMEA standard provides quite a range of sentences, but many relate to non-GPS devices and some others are GPS related but rarely used. We normally recommend the use of NMEA mode for new GPS applications to give maximum compatibility with all GPS receivers. Most GPS receivers also have a binary mode but it is normally best to reserve the use of binary GPS protocols for applications that really require their use, such as those requiring position updates of greater than once per second. This protocol works on the baud rate of 4800.
$GPGGA Global positioning system fixed data
$GPGLL Geographic position - latitude / longitude
$GPGSA GNSS DOP and active satellites
$GPGSV GNSS satellites in view
$GPRMC Recommended minimum specific GNSS data
$GPVTG Course over ground and ground speed
$GPGGA Sentence (Fix data)
$GPGGA,235947.000,0000.0000,N,00000.0000,E,0,00,0.0,0.0,M,,,,0000*00 Example (signal acquired):
Field Example Comments
Sentence ID $GPGGA
UTC Time 092204.999 hhmmss.sss
Latitude 4250.5589 ddmm.mmmm
N/S Indicator S N = North, S = South
Longitude 14718.5084 dddmm.mmmm
E/W Indicator E E = East, W = West
Position Fix 1 0 = Invalid, 1 = Valid SPS, 2 = Valid DGPS, 3 = Valid PPS
Satellites Used 04 Satellites being used (0-12)
HDOP 24.4 Horizontal dilution of precision
Altitude 19.7 Altitude in meters according to WGS-84 ellipsoid
Altitude Units M M = Meters
Geoid Seperation Geoid seperation in meters according to WGS-84 ellipsoid
Seperation Units M = Meters
DGPS Age Age of DGPS data in seconds
DGPS Station ID 0000
Output Protocols from a GPS Receiver
Various Output Protocols from a GPS Receiver