____________________________________________________________________
Page 5-102
Cirrus Perspective™ Line Maintenance Manual
Rev. E
190-00920-00
5.17
Troubleshooting
the
S
‐
TEC
55x
Interface
5.17.1
Interface
Summary
•
Autopilot
computer
is
interfaced
to
GIA2
only
•
Utilizes
S
‐
TEC
pitch
servo
and
Cirrus
pitch
trim
motor
for
vertical
control
•
Utilizes
Cirrus
roll
trim
motor
only
for
lateral
control
•
Utilizes
S
‐
TEC
turn
coordinator
and
S
‐
TEC
altitude
hold
chamber
•
Mode
annunciation
and
FD
are
displayed
on
the
PFD
in
normal
mode
and
on
the
MFD
if
the
Perspective
system
is
in
reversionary
mode
•
Eaton
switches
on
LH
side
of
instrument
panel
annunciate
“AP
ON”
(bottom
half
of
switch)
and
“AP
OFF/FD
ON”
(top
half
of
switch)
•
GPS
steering
utilizes
an
ARINC
429
buss
between
GIA2
and
the
55x
•
Altitude
preselect
data
utilizes
an
RS
485
buss
between
GIA2
and
the
55x
•
Analog
outputs
from
GIA2
drive
the
GS
deviation,
GS
flag,
Nav
deviation,
Nav
flag
to
the
55x
•
Pitch
and
Roll
analog
steering
outputs
from
the
55x
drive
the
FD
bar
inputs
to
GIA2
which
in
turn
are
displayed
on
the
PFD
•
Clock,
Sync
and
Data
are
used
to
transfer
the
mode
annunciation
information
from
the
55x
to
GIA2
which
in
turn
is
displayed
on
the
PFD
or
MFD
in
reversionary
mode
•
DC
course
and
heading
datum
outputs
from
GIA2
drive
the
55x
associated
inputs
5.17.2
Failure
Modes
•
Loss
of
MFD
or
GIA2
o
All
mode
annunciation
removed
from
PFD
o
FD
bars
removed
from
PFD
o
S
‐
TEC
computer
remains
in
basic
altitude
hold
(if
selected
prior
to
loss)
and
HDG
(if
selected
prior
to
loss)
and
is
annunciated
on
the
autopilot
controller
that
way.
Keep
in
mind
that
because
there
is
no
longer
any
communication
between
the
autopilot
computer
and
the
Perspective
system
there
is
no
way
to
input
a
heading
error
to
drive
the
autopilot.
•
Loss
of
PFD
o
No
loss
of
autopilot
functionality.
Mode
annunciation
and
FD
transferred
to
MFD
in
reversionary
mode
Summary of Contents for Cirrus Perspective SR20
Page 2: ......
