JMA-5300MkIIsm

INDEX > 2.System Configulation > 2.3 Function System Diagram
The functional system diagram of the system's display unit is shown in Fig.2-6.
A. Starting the System
Turning on the power switch of the operating unit starts the power supply circuit
CBD-1655A, and the various power supply voltages are supplied to the I/F circuit
CMH-2201 and to the radar process circuits. The CPUs in the display unit also
start and perform the initial settings.
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After the power is turned on, the local CPU in the radar process circuit CDC-
1332, the graphic CPU, the CPU in the AIS processing circuit CDC-1325 and the
operation CPU in the operation circuit CCK-979 are released from their reset
status, perform the initialization of the respective hardware items to which they
are connected, and wait for control commands from the main CPU.
The main CPU is released from the reset status and initializes the radar image/
display function before initializing the entire system. First, it send initial settings
commands to the local CPU to initialize the radar signal settings, and it sends a
communication initialization command to the operating unit CPU to initialize the
operation functions. The main CPU also writes a program to the memory in the
DSP of the ARPA process circuit to start the DSP and issue an initialization
command to the CPU in the AIS process circuit to initialize the AIS process
circuit.
After that, the main CPU sets the internal status according to the sensor data input
from the various communication lines, such as the GYRO I/F and GPS, and issues
an initialization command to the scanner unit via the communication line to
initialize the scanner unit. This concludes the initialization of the system.
B. Circuit Functions
TThe GYRO I/F unit NCT-59A processes the gyro signal, which is in the synchro
or step format, calculates the true azimuth, and sends the true azimuth data to the
radar process circuit at regular intervals using serial communication. As long as
the GYRO I/F unit is receiving the gyro signal, it is supplied with power and the
CPU operates even if the display unit power is turned off. Therefore, even if the
display unit power is turned off, the GYRO I/F circuit can continue to calculate
the true azimuth.
The operating circuit CPU detects the operating status of the switches and dials of
the operation panel and sends the operation data to the main CPU through the
communication line.
The radar signal process circuit in the radar process circuit digitalizes the radar
signals it receives from the scanner unit (the radar video signal, the transmission
timing signal, and the antenna rotation signal), suppresses unwanted waves, and
draws and displays a radar image in accordance with the display screen.
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