RS232 serial cable pin definition and common connections
RS232 serial cable is used for serial communication between devices and is widely used. Compatibility of serial cables is high. The most common application: desktop computer to connect a variety of serial devices, such as computer and tax control machine, digital machine tools, PDA, Modem, set-top box, bar code machine, industrial instruments and other serial devices to achieve communication functions!
The connection method of RS232 serial port depends on the actual connection device, let's take a look at its pin positioning. At present, the RS232 serial cable interface is DB9 pin, and the RS232 serial cable interface pins are divided into two rows. How to distinguish the serial cable pins?
In the case of the face and interface face up: a row of 5 pins, from left to right, corresponding to pins 1-5:1 row of 4 pins. From left to right, corresponding to pins 6-9.
Needles, definitions, symbols
1.carrier detect
2.Receive data RXD
3.Send data TXD
4.Signal grounding SG
5.The data terminal is ready for DTR
6.Data ready DSR
7.Request to send RTS
8.Clearing sent CTS
So where are the methods of RS232 serial cable direct connection and exchange connection used?
Under normal circumstances, the connection and communication between the device and the computer require a direct connection of the RS232 serial port line; Device-to-device connection communication will use the crossover of the RS232 serial cable. When selecting an RS232 serial cable, select a different connection mode based on the actual connection of the two devices.
