User's Guide

Table Of Contents
User Guide for the Envoy Data Link
Document Number: UG-15000 Rev. A Page 117 of 173
C.2 CPDLC Uplink Message Elements
The following FANS 1/A+ A/1 and ATN B1 CPDLC uplink messages are supported by Envoy. The
CPDLC UM/Example coluumn shows the elements expected in an uplink. If a UM is received with
elements other than those shown, it will result in the following downlink error message:
MESSAGE NOT SUPPORTED BY THIS AIRCRAFT
In the table beow, supported messages are color-coded based on CPDLC protocol:
FANS and ATN common
FANS only
ATN only
This table shows message ID, format, and description
ID
CPDLC UM/Example
Use/Intent
DO-258A
0
UNABLE
Notification that ATSU cannot comply with the
request.
Table 4.6-6
Responses/
Acknowledge-ments
1
STANDBY
Notification that ATSU has received the message
and will respond.
2
REQUEST DEFERRED
Notification that ATSU has received the request
but it has been deferred until later.
3
ROGER
Notification that ATSU has received and
understood the message.
4
AFFIRM
Yes.
5
NEGATIVE
No.
6
EXPECT [level]
EXPECT 25000FT
Notification that a level change instruction should
be expected.
Table 4.6-7 Vertical
Clearances
7
EXPECT CLIMB AT [time]
EXPECT CLIMB AT 1232
Notification that an instruction should be
expected for the aircraft to commence climb at
the specified time.
8
EXPECT CLIMB AT [position]
EXPECT CLIMB AT KXX
Notification that an instruction should be
expected for the aircraft to commence climb at
the specified position.
9
EXPECT DESCENT AT [time]
EXPECT DESCENT AT 1232
Notification that an instruction should be
expected for the aircraft to commence descent at
the specified time.
10
EXPECT DESCENT AT [position]
EXPECT DESCENT AT XXZ
Notification that an instruction should be
expected for the aircraft to commence descent at
the specified position.
11
EXPECT CRUISE CLIMB AT [time]
EXPECT CRUISE CLIMB AT 1232
Notification that an instruction should be
expected for the aircraft to commence cruise
climb at the specified time.
12
EXPECT CRUISE CLIMB AT
[position]
EXPECT CRUISE CLIMB AT XYZ
Notification that an instruction should be
expected for the aircraft to commence cruise
climb at the specified position.
13
AT [time] EXPECT CLIMB TO
[level]
AT 1232 EXPECT CLIMB TO
25000FT
Notification that an instruction should be
expected for the aircraft to commence climb at
the specified time to the specified level.
14
AT [pos] EXPECT CLIMB TO [level]
AT XYZ EXPECT CLIMB TO
25000FT
Notification that an instruction should be
expected for the aircraft to commence climb at
the specified position to the specified level.
15
AT [time] EXPECT DESCENT TO
[level]
AT 1232 EXPECT DESCENT TO
25000FT
Notification that an instruction should be
expected for the aircraft to commence descent at
the specified time to the specified level.