User's Manual

Table Of Contents
©1999 Navia Aviation AS 21464-5 Detailed Description
USER MANUALNORMARC 7050
MARKER BEACON
12-13
CI1376 performs interconnections between two TX1373 transmitters (TX1 and TX2), two
MO1374 monitors (MO1 and MO2) and two PS1375 power supplies (PS1 and PS2) and the
external connectors.
TRANSMITTER CHANGE OVER
The TX_TO_AIR signal (driven by the station control software in MO1374) controls which
transmitter is connected to the antenna and which is connected to the dummy load. The
change over function is performed by an RF relay and the dummy load is a suitable 50 resis-
tor.
BATTERY PROTECTION
A voltage comparator compares the V28P signal (on the PS1375 side) to a reference voltage.
If V28P drops below 22V, the comparator disconnects the battery (V28P_PROT). The battery
is reconnected when V28P exceeds 22V. If external chargers are used (to extend battery
backup time) an external battery protection circuit has to be used and the CI1376 protection
circuit is bypassed.
12.1.5 LC 1377 Local Control and Display/Keyboard Interface
12.1.5.1 General description
LC1377 is an interface card between MO1374 (monitor/TX control w/CPU) and the man/
machine interface (local control pushbuttons/LEDs and LCD/keyboard pushbuttons) of the
Marker Beacon.
12.1.5.2 Block Diagram
Figure 12-5 LC 1377 block diagram
LCD
w/KEYBOARD
LOCAL CONTROL
STATUS LEDs
LOCAL CONTROL
PUSH BUTTONS
AND SWITCHES
RS232
CONNECTOR
TO LOCAL PC
LCD
CONTRAST
ADJUSTMENT
3
8
8
8
15
LC_CTRL_BUS
LCD_DATA[7:0]
KB[7:0]
V12N
VDD
GND
LC_LED[14:0]
LC_KEY[7:0]
LOCAL_TXD
LOCAL_RXD
LOCAL_RTS
LOCAL_CTS
HBK820/1