Because RS232 and RS485 are specified to be electrically compatible, you can create a cable to wire directly from RS232 to RS485 by connecting to only the RS485 - (minus) side of the signals.
For direct connection from a standard AT PC RS232(Male) serial port to any S90 or PacSystems 15 pin RS485(Female) serial port:
Cheater Cable RS232 computer to RS485 PLC
JUMP PINS 7---8 (RTS/CTS) on the 9 pin computer side
JUMP PINS 6---15 (RTS-/CTS-) and 8---14 (CTS+/RTS+) on the 15 pin PLC side
*** Keep this cable at 10 Feet or less in length ***
Note that an IBM XT port must switch pins 2 and 3 as they are opposite the AT computer port
This knowledge can be used to connect any RS232 device to any RS422/485 device.
Use this knowledge at your own risk of communications loss.
For direct connection from a standard AT PC RS232(Male) serial port to any S90 or PacSystems 15 pin RS485(Female) serial port:
Cheater Cable RS232 computer to RS485 PLC
JUMP PINS 7---8 (RTS/CTS) on the 9 pin computer side
JUMP PINS 6---15 (RTS-/CTS-) and 8---14 (CTS+/RTS+) on the 15 pin PLC side
*** Keep this cable at 10 Feet or less in length ***
Note that an IBM XT port must switch pins 2 and 3 as they are opposite the AT computer port
This knowledge can be used to connect any RS232 device to any RS422/485 device.
Use this knowledge at your own risk of communications loss.