Board - Sony WLL-RX55 Maintenance Manual

1-6-7. AT-156 Board
The 32-bit microcomputer IC201 on the AT-156 board
communicates with each block of the unit using serial data
"IIC1 DATA" and 8-bit parallel data "CPU DATA" to
control the WLL-RX55 system. The 16-bit flash memory
IC305 incorporates the control program. Two 1M-bit
SRAMs (IC307 and IC308) are used as working memory.
The NVRAM IC309 backs up the menu setting right
before power OFF.
This board performs serial communication with the WLL-
CA55, the external controller and the front panel through
the 700 Protocol Interface. The DSP IC901 on this board
compresses the intercom signal selected on the AU-297
board. In addition, this board multiplexes compressed
intercom signal, camera control signals, tally signal, and
reference synchronization information, performs QPSK
modulation, and then outputs the signals as a serial data to
the AU-297 board.
Further, this board separates wireless ID, camera control
return signals, and intercom audio data from the data
received from WLL-CA55, and then transfers them to the
EL display unit, the external controller, and the AU-297
board respectively.
The microcomputer controls the following for the circuits
of WLL-RX55.
. For the TUN-10 board, sets a reception frequency and
monitors abnormalities such as PLL unlocking.
. For the RX-89 board, sets default values for the OFDM
demodulator IC and PLD.
. For the DEC-146 board, sets default values for the
MPEG decoder and PLD.
. For the VA-220 board, sets default values for the FPGA
and analog video encoder.
. For the AU-297 board, sets default values for the AD/
DA converter ICs.
. Sends character information to the EL display unit.
. Monitors rotation direction and angle of the rotary
encoder for menu selection.
The 60-pin connector CN401 is used for updating the
control program. When a ROM card storing the program is
inserted into the connector, the microcomputer reads the
ROM data and transfers it to the flash memory IC305.
WLL-RX55
1-6-8. AU-297 Board
The AU-297 board performs audio/intercom/tally process-
ing.
Audio signal transmitted from a camera is MPEG decoded
and converted to baseband digital signal on the DEC-146
board, and then input into this board.
On this board, the baseband digital signal is D/A convert-
ed, level adjusted, and then output from the XLR connector
to the external unit.
Respective intercom signals of engineer, producer and
program are connected to this board via the D-sub connec-
tor on the rear panel.
The front intercom line is connected to this board through
the 5-pin XLR connector on the front panel.
A selected intercom signal is A/D converted on the AU-
297 board, and is digitally compressed on the AT-156
board, and then digitally modulated together with the
camera control signals. Further, these signals are D/A
converted on this board and output from the CAMERA
CONTROL pin (3-pin XLR connector).
One intercom line for connection to a camera is provided,
through which the intercom signal is transmitted to the
camera using the wireless microphone system.
1-6-9. PS-667 Board
The WLL-RX55 unit is supplied with AC input and DC
input from the 4-pin XLR connector.
The AC input is fed through the switch to the switching
regulator in the power supply block.
The PS-667 board is supplied with "DC12V (AC)" from
the switching regulator and "DC12V (DC)" from the DC
IN connector. If both inputs are supplied, the AC input is
selected by the selection circuit.
The rated DC input voltage of the PS-667 board is 10.5 to
17 V. The DC input voltage is always checked by IC31.
When a voltage outside the rated voltage range is input,
power supply to the subsequent circuits is shut off. The DC
input voltage is monitored by the AT-156 board and
displayed on the display panel.
The PS-667 board has several DC-DC converters and feeds
DC power to the internal boards, fan, RCP (REMOTE
connector), and wireless microphone system (DC OUT
connector).
A temperature sensing circuit using thermistor TH201 is
connected to the DC-DC converter for the fan, which
controls the fan voltage so as to regulate the temperature
inside the unit.
1-11 (E)