MAINTENANCE
Honeywell MN!K!b
The ISDU selects data from any one of three IRUS for display and provides
initial position or heading data to
Operator inputs to the ISDU provide
navigational data for display. The
● Keyboard
. Display
● System display (SYS DSPL) switch
● Display select (DSPL SEL) switch
● Dimmer knob
the IRUS.
position data to the IRU and select
ISDU contains:
2. c. (1)
(2)
(3)
Keyboard
(a) The keyboard is used to enter 1atitude and longitude in the
alignment mode or magnetic heading in the attitude mode. The
ISDU then sends the entered data simultaneously to all IRU
in
multiple-channel installations.
(b) The keyboard contains 12 keys.
Five of the 12 keys are dual
function: N/2, W/4, H/5, E/6, and S/8. A dual-function key is
used to select either the type of data (latitude, longitude, or
heading) or numerical data to be entered. Single-function keys
are used to select only numerical data.
(c)
The clear [CLR] and enter [ENT] keys contain green cue 1ights
which, when lit, indicate that operator action is required.
[CLR] is used to remove data erroneously entered. [ENTJ is
used to send data to the IRU.
Display
The 13-digit alphanumeric split display shows two types of
navigation data at the
same time. The display is separated into one
group of six digits (positions 1 through 6) and one group of seven
digits (positions 7 through 13). Punctuation marks (located in
positions
3, 5, 6, 10,
12, and 13) light when necessary to indicate
degrees, decimal points, and minutes.
System Display (SYS DSPL) Switch (See Figure 2-6.)
The SYS DSPL switch is used to select the IRU (position 1, 2, or3)
from which the displayed data originates.
If the switch is set to
OFF, the ISDU cannot send or receive data from any IRU.
22-14-00
Page 125
Aug 15/91
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