Oki OKIOFFICE 1200, Field Engineering Manual, Page: 188 / 207

6-6
RS-232C interface cable
The RS-232C port on your newly installed RS-232C interface has a DB-25 (standard 25-pin serial)
female receptacle which accepts a male DB-25 cable plug. Your computer’s port may have either a
DB-25 or DB-9 (9-pin) receptacle.
If necessary, see the chart below for detailed information on the pin assignment for your fax machine’s
RS232C port.
Note: For more information on the computer’s serial interface port, see the computer’s operating
instructions.
Note: Please use the RS-232C interface cable shorter than 3 meters.
Pin assignment
Pin No. Signal code Signal name Contents
2 TXD Transmitted data
Data signal sent from computer
to your fax.
3 RXD Received data
The data sent to computer by
your fax.
4 RTS Request to send Signal for request to send data.
5 CTS Clear to send
Data Enable signal for data
transmission from your fax to
your computer.
6 DSR DCE ready Turning on always.
7 SG Signal ground Ground for signal.
20 DTR DTE ready
Data Terminal Enable – ready to
communicate
Signal direction
25-pin type
Your fax Your computer
2 TXD 2 TXD
3 RXD 3 RXD
4 RTS 4 RTS
5 CTS
5 CTS
6 DSR 6 DSR
7 SG 7 SG
20 DTR 20 DTR
9-pin type
Your fax Your computer
2 TXD
2 RXD
3 RXD 3 TXD
4 RTS 4 DTR
5 CTS 5 SG
6 DSR 6 DSR
7 SG 7 RTS
20 DTR
8 CTS
RS-232C Test
This mode is for return back test of the RS-232C port.
Refer to “RS-232C test,” page 3-68 for the procedure.