Garmin GNC 420(A) Pilot's Manual & Reference page 222

SECTION 11
ADDITIONAL FEATURES
Monitoring the Data Link
The Data Link Status Page provides an indication of
the integrity of the Data Link. The Data Link Page allows
the pilot to monitor the system and determine the possible
cause of a failure.
View the Data Link Status Page:
1) From the AUX Page Group, select the Data Link
Page.
Highlight 'Data Link Status' and press the ENT
2)
Key.
3) The Data Link Status Page (Figure 11-47) is
displayed.
Figure 11-47 Data Link Status Page
The GDL 49 Datalink Status Page shows the following
fields:
• TX Queue - Shows the number of requests in the
GDL 49' s transmit queue waiting to be sent to the
satellite.
• RX Queue - Shows the number of responses in the
GDL 49' s receive queue waiting to be sent to the
GNC 420.
• Sat ID/Connectivity - Shows the current satellite
in view and also indicates the status of the current
satellite connection. See Table 11-8.
11-32
MESSAGE
'_ _ _'
'Data Link has
failed'
'Linked to sat'
'Satellite in view'
'Searching...'
• SATCOM Operation - This field indicates the
MESSAGE
'_ _ _'
'Idle'
'Receiving
message'
'Sending message' Transmitting a message.
'Sending request'
• SATCOM SER NUM - This field shows the serial
• GDL SW - This field shows the currently installed
GNC 420(A) Pilot's Guide and Reference
SAT ID/CONNECTIVITY FIELD
DESCRIPTION
RS-232 communication with the GDL
49 has been lost.
There is a disconnect inside the GDL
49.
Can exchange data with the satellite.
Found satellite but have not yet
identified it.
No satellite is currently in view.
Table 11-8 Sat ID/Connectivity Field
current activity being performed by the satellite
communicator within the GDL 49. Table 11-9
lists the messages that can be displayed, including
interpretations of the most common ones:
SATCOM OPERATION FIELD
DESCRIPTION
Unknown task is being performed,
or RS-232 communication with the
GDL 49 has been lost.
Waiting to perform the next task.
Receiving a response from the
satellite.
Transmitting a request to the
satellite.
Table 11-9 SATCOM Operation Field
number assigned to the GDL 49' s internal satellite
communicator.
software version for the GDL 49.
190-00140-20 Rev. K