Olympus OEP-3 Service Manual page 153

4-4-4. RS Communication Control
RS-232C interface
A signal is converted from serial to parallel by IC250 (uPD71051GU) that is connected to CPU via a bus.
Input and output signals are level-converted by IC280 and IC281 (SP232CAN).
The last output signal is as follows:
Active: 8 V
Non-active: _8 V
The TP position is as follows:
Active: 0 V
Non-active: +5 V
Signal line name I/O
TXD Output
RXD Input
RTS Output
CTS Input
DTR Output
DSR Input
Communication format
System Asynchronous system
Data length 8 bits
Stop bit 1 bit
Parity None
Baud rate 1200/2400/4800/9600 bps (Menu switching)
Set the transfer rate to 9600 when upgrading the firmware on the PRT-13 board.
OEP-3 V1 (UC)
Description
Communication data (UP → External)
Communication data (External → UP)
Communication enable (UP → External)
Communication enable (External → UP)
Operation status (UP → External)
Operation status (External → UP)
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