72 GPSMAP 182/182C Owner’s ManualM AIN MENU > C OMM TABManually enter amagnetic variation.• Distance, Speed and Elevation—select the units of measurefor distance, speed, and elevation readouts in nautical(nm, kt, m), statute (mi, mh, ft), or metric (km, kh, m) terms.• Depth—select units of measurement for depth in feet (ft),fathoms (fa), or meters (m).• Temperature—select the units of measure for temperaturein Fahrenheit (°F) or Celsius (°C).Comm (Communications) TabThe Communications tab controls the input/output format usedwhen connecting your GPSMAP 182/182C to external NMEAdevices, such as an external Sonar Module, a DGPS beaconreceiver, a personal computer, or another Garmin unit.NOTE: If a DGPS receiver is used, WAAS capability isautomatically turned to off. See pages 98 and 99 for wiring andNMEA version information.The unit supports two input/output ports.Port 1• Garmin Data Transfer—is the proprietary format usedto upload/download MapSource data, exchange waypoint,route, track, almanac, and proximity data with a PC oranother Garmin unit. When you select Garmin Data Transfer,there are 11 Transfer Modes to choose from: Host, RequestAlmanac, Request Proximity, Request Routes, RequestTracks, Request Waypoints, Send Almanac, Send Proximity,Send Routes, Send Tracks, and Send Waypoints.• Garmin Remote Sonar—supports a Garmin external SonarModule interface.
