RS232

From HwB

Common names: EIA-232D (RS232-D), ITU-TSS (CCITT) V.24/V.28, ISO 2110

Pinout

Dsub25m.png

25 PIN D-SUB MALE at the DTE (Computer).

Dsub25f.png

25 PIN D-SUB FEMALE at the DCE (Modem).

Pin Name RS232 V.24 Dir Description
1 GND n/a 101 Arrow.png Shield Ground
2 TXD BA 103 Arrowr.png Transmit Data
3 RXD BB 104 Arrowl.png Receive Data
4 RTS CA 105 Arrowr.png Request to Send
5 CTS CB 106 Arrowl.png Clear to Send
6 DSR CC 107 Arrowl.png Data Set Ready
7 GND AB 102 Arrow.png System Ground
8 CD CF 109 Arrowl.png Carrier Detect
9 - - RESERVED
10 - - RESERVED
11 STF 126 Arrowr.png Select Transmit Channel
12 S.CD SCF 122 Arrowl.png Secondary Carrier Detect
13 S.CTS SCB 121 Arrowl.png Secondary Clear to Send
14 S.TXD SBA 118 Arrowr.png Secondary Transmit Data
15 TCK DB 114 Arrowl.png Transmission Signal Element Timing
16 S.RXD SBB 119 Arrowl.png Secondary Receive Data
17 RCK DD 115 Arrowl.png Receiver Signal Element Timing
18 LL LL 141 Arrowr.png Local Loop Control
19 S.RTS SCA 120 Arrowr.png Secondary Request to Send
20 DTR CD 108.2 Arrowr.png Data Terminal Ready
21 RL RL 140 Arrowr.png Remote Loop Control
22 RI CE 125 Arrowl.png Ring Indicator
23 DSR CH 111 Arrowr.png Data Signal Rate Selector
24 XCK DA 113 Arrowr.png Transmit Signal Element Timing
25 TI TM 142 Arrowl.png Test Indicator

Notes:

  • Direction is DTE (Computer) relative DCE (Modem).
  • RS232 column is RS232 circuit name.
  • ITU-T column is ITU-TSS V.24 circuit name.
  • Do not connect SHIELD(1) to GND(7).

Details

Value Name Voltage
0 Space +3 to +12 VDC
1 Mark -3 to -12 VDC

Note: -3 to +3 is undefined value.

RS232 Diagram.svg

Contributions