Garmin GPSMAP 172C Owner's Manual - Page 67

The Differential SNR (Signal to Noise Ratio) indicates, on a scale to 0-30db with 30db being the best, the strength of the DGPS signal being received. The SNR depends upon the mounting of your DGPS receiver and the distance from the DGPS transmitting station. The GPS Info tab features an options menu that provides access to functions and features relating to the GPS Info display. The following options are available by pressing MENU on the GPS Info Tab of the Main Menu: • Start/Stop Simulator- toggles the unit simulator on or off. Retail Demo mode restores factory settings to the unit if left unattended for over two minutes. This mode should only be used for display purposes. User waypoints are NOT deleted. • WAAS On/WAAS Off- toggles the WAAS capability of the receiver on or off. • Track Up/North Up- allows you to select between a north up or track up sky view display for the GPS Info display only. • AutoLocate- allows the receiver to locate your position automatically. This process can take up to five minutes. • Initialize Position- allows you to initialize the receiver graphically on the Map Page to initially help the receiver acquire more quickly. See page 4 for instructions on initialization. • Set 2D Elevation- allows you to manually enter the elevation when in 2D or Simulator mode only. Any elevation entered is automatically calculated when the GPS is in 3D mode. To select a menu option: 1. Using the ARROW KEYPAD, highlight the desired option and press ENTER. F NOTE: If a DGPS receiver is attached to the unit and Garmin DGPS, RTCM In/NMEA Out, or Other DGPS is enable on Port 2, WAAS is automatically disabled (WAAS Off). It is not possible for the GPSMAP 172/172C to receive WAAS and DGPS corrections at the same time. Reference Main Menu: GPS Tab Options GPS Tab Options Menu 57