Garmin GNC 420W Pilots Guide - Page 208

SECTION 11 ADDITIONAL FEATURES 11.3 Weather Data Link Interface This section is written for: • Garmin GNC 420 Main System Software Version 5.01 and later • GDL 49 Main Software Version 2.03 and later • GDL 69/69A Main Software Version 2.14 and later Some differences in operation may be observed when comparing the information in this manual to earlier or later software versions. NOTE: This section is written exclusively for GNC 420 units that are configured with the GDL 49 or GDL 69(A) Data Link Satellite Receiver. Refer to the 400/500 Series Display Interfaces Pilot's Guide Addendum (190-00140-10) when interfacing with non-Garmin products. Introduction GNC 420 units can interface with the GDL 49 or the GDL 69/69A. The GNC 420 unit provides the display and control interface for the textual and graphical weather data link. Satellite up-linked textual and graphical weather data is received by the GDL 49 on a request/reply basis. Transmissions are made using bursts of compressed data at a rate of 4800 bps. Weather data transmissions are streamed directly to the GDL 69/69A from the XM Satellite Radio network. The following operational differences are noted between the GDL 69/69A and the GDL 49: • GDL 49 - NEXRAD and METAR data is collected by the National Weather Service and disseminated to Meteorlogix™, a weather information provider. This data is then delivered to a weather server in the Echo Flight Message System. With the weather data on the system, an incoming customer request is filled, logged, and turned around for delivery to ORBCOMM in less than five seconds (ORBCOMM is a provider of global messaging services using a constellation of 26 low-Earth orbiting satellites). The message is relayed from the satellites to the GDL 49 aboard the aircraft. Once the GDL 49 receives the message, it is displayed on the GNC 420 unit. • GDL 69/69A - NEXRAD and METAR data is collected by the National Weather Service and disseminated to WxWorks™, a weather information provider. This data is then delivered to XM Satellite for rebroadcast. Data from two XM satellites is then made immediately available to XM customers. The GDL 69/69A receives streaming weather data, processes the data, then sends it to the GNC 420 unit for display. Functions provided by the Weather Data Link system include: • Request for and display of NEXRAD radar imagery. • Request for and display of text-based METAR data. • Request for and display of a compressed form of METAR data that allows icon representations at reporting stations on a moving map indicating visibility, ceiling, etc. • Position tracking services are provided through periodic position report transmissions from the GNC 420 unit (available with GDL 49 only). 11-18 GNC 420(A) Pilot's Guide and Reference 190-00140-20 Rev. K