Main Indicator - Garmin GPS 400W, GNC 420W Installation Manual

4.4

Main Indicator

4.4.1 Main Indicator Function
The Main Indicator displays both lateral and vertical deviation from selected course, To/From
indications, lateral and vertical flags and superflags.
The "CDI" key on the bezel of the GNS 430W takes the place of remote "NAV/GPS" switches, and is
used to toggle between display of GPS and VOR/ILS navigation display on a remote indicator. The
Navigation source is annunciated on the display above the 'CDI' key. The Navigation method is
optionally annunciated externally by connecting to the VLOC ANNUNCIATE output (P4001-1) and
GPS ANNUNCIATE output (P4001-2). GPS and VOR/ILS navigation may be toggled externally when
the CDI SOURCE SELECT input (P4001-73) is momentarily grounded. See section 4.5 for more
information on the external annunciators and switches.
An OBS resolver connection to the GPS is preferred, but not required. For the GNS 430W, an OBS
resolver typically is connected to the MAIN OBS inputs for use with the GNS 430W VOR receiver.
4.4.2 Main Indicator Electrical Characteristics
4.4.2.1 Deviation
MAIN +LEFT
MAIN +RIGHT (1.65V COMMON)
MAIN +UP (1.65V COMMON)
MAIN +DOWN
The deviation output is capable of driving up to three 1000 Ω meter loads with ±150 mVDC ±10% for
full-scale deflection. The drive circuit provides for more than full-scale deflection with a maximum
course deviation output voltage of ±300 mVDC ±10%.
4.4.2.2 TO/FROM
MAIN +TO (1.65V COMMON)
MAIN +FROM
The output is capable of driving up to three 200 Ω meter loads. When indicating TO, MAIN +TO is +190
±40 mVDC with respect to MAIN +FROM. When indicating FROM, MAIN +TO is -190 ±40 mVDC
with respect to MAIN +FROM. When invalid information is present (Flag IN VIEW) the TO/FROM
output is 0 ±10 mVDC.
4.4.2.3 Flags
MAIN LATERAL +FLAG
MAIN LATERAL -FLAG (GROUND)
MAIN VERTICAL +FLAG
MAIN VERTICAL -FLAG (GROUND)
The Flag output is capable of driving up to three 1000 Ω meter loads. When valid information is present
(Flag OUT OF VIEW) the Flag output is 375 ±80 mVDC. When invalid information is present (Flag IN
VIEW) the Flag will have an output is 0 ±25 mVDC.
400W Series Installation Manual
190-00356-02
Pin Name
Pin Name
Pin Name
Connector Pin
P4001 21
P4001 22
P4001 27
P4001 28
Connector Pin
P4001 25
P4001 26
Connector Pin
P4001 23
P4001 24
P4001 29
P4001 30
I/O
Out
Out
Out
Out
I/O
Out
Out
I/O
Out
Out
Out
Out
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Rev. E