Garmin GPS 16x Technical Specifications

Also see for 16X LVS: Declaration of conformity

Garmin GPS 16x Technical Specifications Manual pdf 15 page image

190-00228-08 GPS 16x Technical Specifications Rev. CPage 114The GPS 16x series products interface protocol design on COM1 is based on the National Marine ElectronicsAssociation’s NMEA 0183 ASCII interface specification. The COM2 port can receive differential GPS (DGPS)correction data using the Radio Technical Commission for Maritime Services’ RTCM SC-104 standard. Thesestandards are fully defined in NMEA 0183, Version 3.0 (copies may be obtained from NMEA,SOFTWARE INTERFACEwww.nmea.org) andRTCM Recommended Standards For Differential Navstar GPS Service, Version 2.2, RTCM Special Committee No.104 (copies may be obtained from RTCM, www.rtcm.org).The GPS 16x series products interface protocol, in addition to transmitting navigation information as defined byNMEA 0183, transmits additional information using the convention of Garmin proprietary sentences.Binary information can alternatively be output on the COM1 port; see Appendix B: Garmin Binary Output Formatfor details.The following sections describe the NMEA 0183 data format of each sentence transmitted and received by the GPS16x series products. The baud rate selection, one-pulse-per-second output interfaces and RTCM differential GPSinput are also described.4.1 RECEIVED NMEA 0183 SENTENCESThe following paragraphs define the sentences that can be received on the GPS sensors’ COM1 port. Null fields inthe configuration sentence indicate no change in the particular configuration parameter. All sentences received bythe GPS sensor must be terminated with , the ASCII characters for carriage return (0D hexadecimal) andline feed (0A hexadecimal). The checksum *hh is used for parity checking data and is not required, but isrecommended for use in environments containing high electromagnetic noise. It is generally not required in normalPC environments. When used, the parity bytes (hh) are the ASCII representation of the exclusive-or (XOR) sum ofall the characters between the “$” and “*” characters, non-inclusive. The hex representation must be a capital letter,such as 3D instead of 3d. Sentences may be truncated by after any data field and valid fields up to thatpoint will be acted on by the sensor.4.1.1 Almanac Information (ALM)The $GPALM sentence can be used to initialize the GPS sensor’s stored almanac information in the unlikely eventof non-volatile memory loss or after storing longer than six months without tracking GPS satellites.$GPALM,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>,<10>,<11>,<12>,<13>,<14>,<15>*hh<1> Total number of ALM sentences to be transmitted by the GPS sensor during almanac download. Thisfield can be null or any number when sending almanac to the GPS sensor.<2> Number of current ALM sentence. This field can be null or any number when sending almanac to theGPS sensor.<3> Satellite PRN number, 01 to 32<4> GPS week number<5> SV health, bits 17-24 of each almanac page<6> Eccentricity<7> Almanac reference time<8> Inclination angle<9> Rate of right ascension<10> Root of semi major axis<11> Omega, argument of perigee<12> Longitude of ascension node<13> Mean anomaly<14> af0 clock parameter<15> af1 clock parameter