What is the DB9 interface?
What is the DB9 interface?
1.DB9 interface
D-type data interface connector, used to connect electronic equipment (such as: computer and peripherals) interface standard. Because the shape is similar to the English letter D, it is named D-type interface.According to the number of interfaces, it is subdivided into A type (15 pins), B type (25 pins), C type (37 pins), D type (50 pins), E type (9 pins). Therefore, the common computer parallel port is the DB25 pin connector. The serial port should be a DE9 pin connector.Since the serial ports and parallel ports of early computers used DB25 pin connectors, people used to write down the letters B and D together as the common name of the D-type interface, so that later the computer serial port was changed to 9 pins After the interface, people use DB9 instead of DE9 to call the 9-pin interface. The result of further promotion of this habit is that people now use DBX to represent the D-type interface, and the number X is the number of pins of the interface.
Serial communication interface RS232 9-pin --DB9 is a common DB interfaces on the computer,it can also used in our RS232 keypads.
2.DB9 male and female
1. RS-232 (DB9 female / female) pin definition
Pin number 2 3 5 1, 4, 6 7, 8
Corresponding Signal definition TXD RXD GND Internal connection Internal connection
Note: This port can be directly inserted into the COM port of the computer
2. RS-232 (DB9 male / pin type) pin definition
Pin number 2 3 5 1, 4, 6 7, 8
Corresponding Signal definition RXD TXD GND Internal connection Internal connection