InterfacingThe following formats are supported for connection of externaldevices: GARMIN proprietary Differential GPS (DGPS), NMEA0180, 0182, 0183 (versions 1.5, 2.0, 2.3, 3.01), ASCII Text Output,RTCM SC-104 input (version 2.0), and Garmin proprietary formatsfor connecting to a Mode S transponder for TIS data, and to aGarmin aviation NAV/COM radio.The following are the Approved Sentences for NMEA 0183,version 3.01 output: GPRMC, GPGGA, GPGSA, GPGSV, GPGLL,GPBOD, GPRTE, and GPWPL. The following are the ProprietarySentences for NMEA 0183, version 3.01 output: PGRME, PGRMZ,PGRMM, and PGRMH.The GPSMAP 496 also includes NMEA input with support for theBWC, DBT, DPT, MTW, VHW, VTG, and XTE sentences.Garmin’s proprietary communication protocol is available from theWeb site (www.garmin.com).Removing the GPS AntennaYou can remove the antenna to use an external antenna. After theantenna is removed, the BNC connector is exposed and ready for usewith an external antenna. For information on connecting an externalantenna to the GPSMAP 496, refer to the installation instructionsthat came with the antenna.To remove the GPS antenna:1. Remove the external power cable from the connector on theback of the GPSMAP 496.2. Rotate the antenna to approximately a seven o’clockposition. The alignment notches in the casing must line upwith the notches on the antenna.3. Pull the antenna away from the GPSMAP 496 unit.Removing the GPS Antenna162 GPSMAP 496 Owner’s ManualAPPENDIX > INSTALLATION INFORMATION
