190-00709-05 Rev. D
Garmin G1000 Pilot’s Guide for the Socata TBM 850/900
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AUDIO PANEL AND CNS
4.3 CONTROLLER PILOT DATA LINK COMMUNICATIONS (CPDLC)
The GDR 66 VHF Data Link Transceiver (used for data communication only) provides the link from the
G1000 Integrated Avionics System to the Controller Pilot Data Link Communications system (CPDLC) via ATN
(VDL Mode 2). The CPDLC system provides data link communication between the aircraft and an Air Traffic
Control facility. Communication is normally in the form of text message elements that resemble phraseology
used in voice communications with ATC.
CPDLC SESSION OVERVIEW
The system will manage a CPDLC session with an ATC end system. Once a successful logon has been
completed the system will go into a CPDLC waiting state. In this state the system is waiting for a CPDLC session
to be initiated by the ATC end system. When an ATC end system sends a CPDLC session start command the
flight crew will have the ability send CPDLC downlink messages. CPDLC downlink messages are messages
initiated by the flight crew to ATC. CPDLC uplink messages are messages initiated by ATC to the flight crew.
The ground system manages handoffs between ATC end systems. When the aircraft is nearing the coverage
boundary of the CDA (Current Data Authority) or current facility, the system will be assigned a NDA (Next
Data Authority) or next facility. The NDA is the ATC end system that is waiting to take control of the aircraft.
Upon crossing the boundary between the two ATC end systems, a transfer instruction will be sent to the system
making the NDA the new CDA.
In the event that the CPDLC session is lost and the logon is still active, the system will accept future CPDLC
start commands from ATC.
CPDLC SYSTEM STATUS
The system will reflect the connection status at all times in the Status Window on the CPDLC Messages Page.
The following is a list of possible system states:
•
Router Not Initialized
– The router has not been initialized. This is typical upon power up. This state
should clear after initialization. Persistence of this state would indicate a failure.
•
Link Not Available/Waiting for Link
– The system has initialized the router but does not have an air-
ground connection.
•
Establishing Link
– The system has detected a viable ground station and is attempting to establish an air-
ground connection.
•
Link Available
– The system has established a connection capable of supporting ATN (Aeronautical
Telecommunications Network) traffic. This state indicates that a network logon can be attempted to establish
CPDLC communications.
•
Connecting
– The system has initiated a network logon with an ATC facility.
