Dc-884 Display Controller Mls Output Discrete Logic - Honeywell SPZ-8000 Maintenance Manual

6. C. (15) Optional DC-884 Display Controller, Part No. 7007540-941/942, for
MLS/TCAS Installations
(a) MLS Source Selection
The -941/-942 DC-884 Display Controller is required when a MLS
is
installed.
The DC-884 provides a MLS installed grid/open
programming discrete at pin J1-d. A ground indicates an MLS
is installed. This discrete has priority over the ILS
installed discrete.
MLS
and Bendix
ILS will not
be simultaneously present in an
aircraft due
to symbol generator port limitations. Therefore,
if the MLS and ILS discretes are both set, the DC should
ignore the ILS installed discrete and consider the system as
MLS
installed. This will aid installers of aircraft that
formerly
possessed a Bendix ILS should they neglect to
remove
the
ILS
installed discretes from the DC.
The DC-884 also provides a grid/open MLS select discrete at pin
J1-FF. Control priority over the MLS select
discrete is as
follows:
On-side active NAV
Cross-side active NAV
On-side preview NAV
. Cross-side preview
NAV
This implies that
if the pilot has selected NAV 1,
copilot
selection of
MLS 1 will not toggle the pilot's discrete.
Table 6-4.1 lists the primary cases for this MLS select
discrete.
MLS 1 Select MLS 2 Select
Toggled on
Toggled on
DC-884 NAV
Source MLS 1 Select Preview of MLS 1 MLS 2 Select Preview of MLS 2
Pilot's DC NAV 2 x
copilot's Dc MLS 2 x x
Pilot's DC MLS 2
x
Copilot's DC NAV 2
x
Pilot's DC
MLS 1 x
x
x
Copilot's DC MLS 1 x x x
Pilot's DC MLS 1 x x x
Copilot's DC MLS 2
x
x x
Pilot's DC MLS 2 x x x
Copilot's DC
MLS 1
x
x
x
Pilot's DC
MLS 2
x x
x
Copilot's DC MLS 2
x
x x
DC-884 Display Controller MLS Output Discrete Logic
Table 6-4.1
22-14-00
Page 196.1
Apr 15/93
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