RS232 Port (DB-25). Pinout and Signals. Full RS232 connector

DB25 pin D-SUB male at the DTE (Computer) DB25 pin D-SUB male at the DTE (Computer)
DB25 pin D-SUB female at the DCE (Modem) DB25 pin D-SUB female at the DCE (Modem)

Pin Name Direction Description
1 GND 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 - - RESERVED
10 - - RESERVED
11 STF Select Transmit Channel
12 S.CD Secondary Carrier Detect
13 S.CTS Secondary Clear to Send
14 S.TXD Secondary Transmit Data
15 TCK Transmission Signal Element Timing
16 S.RXD Secondary Receive Data
17 RCK Receiver Signal Element Timing
18 LL Local Loop Control
19 S.RTS Secondary Request to Send
20 DTR Data Terminal Ready
21 RL Remote Loop Control
22 RI Ring Indicator
23 DSR Data Signal Rate Selector
24 XCK Transmit Signal Element Timing
25 TI Test Indicator
Note: Direction is DTE (Computer) relative DCE (Modem).
Note: Do not connect SHIELD(1) to GND(7).
Our software allows you monitor, log, debug and test any your RS232 or COM ports.

RS232 port related links

- RS232 to RS232 connect two DTE devices or computers using DB9 pin connectors.
- RS-232 - RS-232 connect two DTE devices or computers using DB25 pin connectors.
- Serial port interface serial port interface description.