RS-232 pinout

RS232 connector

25 pin D-SUB MALE connector  at the DTE (Computer) 25 pin D-SUB FEMALE connector at the DCE (Modem) Pin Name ITU-T Dir Description 1 GND 101 Shield Ground 2 TXD 103 Transmit Data 3 RXD 104 Receive Data 4 RTS 105 Request to Send 5 CTS 106 Clear to Send 6 DSR 107 Data Set Ready 7 GND 102 System Ground 8 CD 109 Carrier Detect 9 –   – RESERVED 10 –   – RESERVED 11 STF 126 Select Transmit Channel 12 S.CD ? Secondary Carrier Detect 13 S.CTS ? Secondary Clear to Send 14 S.TXD ? Secondary Transmit Data 15 TCK 114 Transmission Signal Element Timing 16 S.RXD ? Secondary Receive Data 17 RCK 115 Receiver Signal Element Timing 18 LL 141 Local Loop Control 19 S.RTS ? Secondary Request to Send 20 DTR 108 Data Terminal Ready 21 RL 140 Remote Loop Control 22 RI 125 Ring Indicator 23 DSR 111 Data Signal Rate Selector 24 XCK 113 Transmit Signal Element Timing 25 TI 142 Test Indicator

Note: Direction is DTE (Computer) relative DCE (Modem). Note: Do not connect SHIELD(1) to GND(7).RS-232D connector 

RJ45 FEMALE connector  at the devices RJ45 MALE connector at the cables Pin Name Dir Description 1 DSR/RI Data Set Ready / Ring Indicator 2 CD Carrier Detect 3 DTR Data Terminal Ready 4 GND System Ground 5 RXD Receive Data 6 TXD Transmit Data 7 CTS Clear to Send 8 RTS Request to Send

Note: Direction is DTE (Computer) relative DCE (Modem). Serial (PC 25) connector 

25 pin D-SUB MALE connector  at the computer Pin Name Dir Description 1 SHIELD – Shield Ground 2 TXD Transmit Data 3 RXD Receive Data 4 RTS Request to Send 5 CTS Clear to Send 6 DSR Data Set Ready 7 GND – System Ground 8 CD Carrier Detect 9 n/c –   10 n/c –   11 n/c –   12 n/c –   13 n/c –   14 n/c –   15 n/c –   16 n/c –   17 n/c –   18 n/c –   19 n/c –   20 DTR Data Terminal Ready 21 n/c –   22 RI Ring Indicator 23 n/c –   24 n/c –   25 n/c –

Note: Direction is DTE (Computer) relative DCE (Modem). Note: Do not connect SHIELD(1) to GND(7).Serial (PC 9) connector 

9 pin D-SUB MALE connector  at the computer Pin Name Dir Description 1 CD Carrier Detect 2 RXD Receive Data 3 TXD Transmit Data 4 DTR Data Terminal Ready 5 GND System Ground 6 DSR Data Set Ready 7 RTS Request to Send 8 CTS Clear to Send 9 RI Ring Indicator

Note: Direction is DTE (Computer) relative DCE (Modem)9 to 25 Serial AdapterThis adapter will enable you to connect a 25 pin serialcable to a 9 pin connector at the computer

9 pin D-SUB MALE connector  at the computer 25 pin D-SUB FEMALE connector to the cable 9-Pin 25-Pin Carrier Detect 1 8 Receive Data 2 3 Transmit Data 3 2 Data Terminal Ready 4 20 System Ground 5 7 Data Set Ready 6 6 Request to Send 7 4 Clear to Send 8 5 Ring Indicator 9 22

 Nullmodem AdapterThis adapter will enable you to use a normal serialcable as a nullmodem

25 pin D-SUB FEMALE connector  at the Computer 25 pin D-SUB MALE connector to the Serial cable Female Male Shield Ground 1 1 Shield Ground Transmit Data 2 3 Receive Data Receive Data 3 2 Transmit Data Request to Send 4 5 Clear to Send Clear to Send 5 4 Request to Send Data Set Ready 6 20 Data Terminal Ready Data Terminal Ready 20 6 Data Set Ready Ground 7 7 Ground

 Nullmodem (25-25) CableUse this cable between two DTE devices (for instance two computers)

25 pin D-SUB FEMALE connector  at the Computer 1 25 pin D-SUB FEMALE connector to the Computer 2 D-Sub 1 D-Sub 2 Receive Data 3 2 Transmit Data Transmit Data 2 3 Receive Data Data Terminal Ready 20 6+8 Data Set Ready + Carrier Detect System Ground 7 7 System Ground Data Set Ready + Carrier Detect 6+8 20 Data Terminal Ready Request to Send 4 5 Clear to Send Clear to Send 5 4 Request to Send

Note: DSR & CD are jumpered to fool the programs to think that they are online.Nullmodem (9-25) CableUse this cable between two DTE devices (for instance two computers)

9 pin D-SUB FEMALE connector  at the Computer 1 25 pin D-SUB FEMALE connector to the Computer 2 D-Sub 9 D-Sub 25 Receive Data 2 2 Transmit Data Transmit Data 3 3 Receive Data Data Terminal Ready 4 6+8 Data Set Ready + Carrier Detect System Ground 5 7 System Ground Data Set Ready + Carrier Detect 6+1 20 Data Terminal Ready Request to Send 7 5 Clear to Send Clear to Send 8 4 Request to Send

Note: DSR & CD are jumpered to fool the programs to think that they are onlineNullmodem (9-9) CableUse this cable between two DTE devices (for instance two computers)

9 pin D-SUB FEMALE connector  at the Computer 1 9 pin D-SUB FEMALE connector to the Computer 2 D-Sub 1 D-Sub 2 Receive Data 2 3 Transmit Data Transmit Data 3 2 Receive Data Data Terminal Ready 4 6+1 Data Set Ready + Carrier Detect System Ground 5 5 System Ground Data Set Ready + Carrier Detect 6+1 4 Data Terminal Ready Request to Send 7 8 Clear to Send Clear to Send 8 7 Request to Send

Note: DSR & CD are jumpered to fool the programs to think that they are onlineModem (9-25) CableThis cable should be used for DTE to DCE (for instance computer to modem) connections with hardware handshaking.

9 pin D-SUB FEMALE connector  at the Computer 25 pin D-SUB MALE connector to the modem Female Male Dir Shield   1 Transmit Data 3 2 Receive Data 2 3 Request to Send 7 4 Clear to Send 8 5 Data Set Ready 6 6 System Ground 5 7 Carrier Detect 1 8 Data Terminal Ready 4 20 Ring Indicator 9 22

At drawing up the information was used from http://wired.hard.ru