RS232-RS485 Convertor Manual V1.02 28/06/01
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2.3 J1 RS-232 Serial Communications Port
Connector type: 9-Way Male D Connector (Female)
Purpose: Connects to PC COM port (RS-232)
This connector is an RS-232 serial port which connects to a spare RS-232 PC COM (serial)
port. The pin-out of this connector is detailed in the table below. The ‘RTS’ pin must be
asserted by the PC COM port in order to enable the RS-485 line driver.
J1 Pin-out:
Pin No. Title RS232 Description RS232
1 DCD Not Connected
2 RXD Receive
3 TXD Transmit
4 DTR Not Connected
5 0 Volt 0V
6 DSR Not Connected
7 RTS RS-485 Transmit ENABLE
The PC must assert this signal line in order to enable the RS-485 line
driver to allow communications from the PC to the remote RS-485
system.
8 CTS Not Connected
9 RING Not Connected
Figure 7