Sony WLL-CA55, Руководство по обслуживанию

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1-11 (E)
WLL-CA55
. Monitors rotation direction and angle of the rotary
encoder for menu selection.
.
Monitors switch operations on the front panel.
The connector CN401 on this board is used for updating
the control program. When a ROM board storing the
program is inserted into the connector, the microcomputer
reads the ROM data and writes it in the flash memory.
1-5-5. PS-678 Board
The PS-678 board is supplied with
+
12 V from the DC IN
connector (4-pin XLR) and the BATT IN connector (5-
pin). When the DC IN connecter is plugged with a connec-
tor from an external unit, the DC IN input is automatically
selected by the switch in the DC IN connector.
This board comprises protection circuits against input
voltage and output current respectively.
Outputs of this board are fed not only to the internal
circuits but also to the DC OUT connector, remote control
panel RCP, and camera.
Protection Against Input Voltage
(1) Against high voltage
If input voltage exceeds + 19 V, it is shut off not to be
fed to the following circuit.
(2) Against low voltage
If a voltage below
+
9 V is input, it is shut off for
prevention of excessive battery discharge.
(3) Against reverse-polarity voltage
If a reverse-polarity voltage is input, it is shut off not
to be fed to the following circuit.
These protections cover voltages up to + 30 V.
The DC LINE switch is connected to each protection
circuit for power ON/OFF.
Protection Against Output Current
After passing through the above protection circuit, the
current of each output (to the internal circuits, DC OUT
connector, RCP, or camera) is detected to protect circuits
against short-circuiting of outputs or overcurrent.
Once protection operation is activated, the protection is not
released unless the power is turned OFF and ON.
The control signal from the microcomputer and the DC
LINE switch are connected to the protection circuit for the
output to the camera to control power supply to the
camera.
1-5-4. IF-936 Board
The main functions of the IF board are to communicate
with the internal blocks, camera, wireless microphone
system, and WLL-RX55, and to control the WLL-CA55
system. A part of intercom signals and the tally signal are
also processed on this board.
n
Processing of a part of intercom signals and the tally signal
on this board is described in “Serial Data from WLL-
RX55” of the APR board.
The 32-bit microcomputer IC201 is the core of the entire
control.
The 16-Mbit flash memory IC305 stores the microcomput-
er’s control program and the 1-Mbit SRAMs IC 307 and
IC308 are used as working memory. The NV RAM IC304
backs up the menu setting, and its data is updated each
time the menu setting is changed.
The microcomputer communicates with the internal blocks
using serial data IIC DAT, DISPLAY SI and 8-bit/16-bit
parallel data CPU DATA to control them. It also commu-
nicates with the camera using serial data COM CONT IN
and OUT to control the camera, and with the camera
through the VPR board using serial data IIC DATA CA to
transfer/receive mode setting. Further, it communicates
with the wireless microphone system using serial data
WRR DI and WRR DO. For communications from WLL-
RX55, 700 protocol serial data is received via the 9-pin
TUNER connector for the wireless microphone system or
AUDIO 1 XLR connector. For communications to WLL-
RX55, the serial data is multiplexed with transmission data
in the FPGA on the DPR board.
The microcomputer also performs mode setting for PLDs
and FPGAs on each board.
The microcomputer provides the following controls for the
circuits of WLL-CA55.
.
For the DPR board, transfers data with a wireless ID
added. For the MPEG encoder module, sets parameters
including encoding rate. For the OFDM modulator
IC301, sets a modulation type and CW output.
CW: Continuous Wave (Single tone with no modulation)
.
For the transmitter, sets an output level and frequency
(2406-2478 MHz for J and CE models, 2406-2466 MHz
for UC model), and monitors abnormalities such as PLL
unlocking.
.
Sends character information to the EL display unit.