DB9 and RS232 are not the same thing. DB9 belongs to the connector model, while RS232 belongs to a communication protocol. Follow our Premier Cable to learn more different between them.

1. DB9

DB9 refers to following type of connector, which has 9 pins. According to the number of interfaces, it is subdivided into Type A (15 pins), Type B (25 pins), Type C (37 pins), Type D (50 pins), and Type E (9 pins). The common computer parallel port is a DB25 pin connector, while the serial port should be a DE9 pin connector. Generally, only three ports, rx, tx, and Gnd, are used for communication.

Due to the early use of DB25 pin connectors for both serial and parallel ports in computers, people used to write down the letters B and D together as a common name for a D-type interface. As a result, after the computer serial port was changed to a 9-pin interface, people used DB9 instead of DE9 to refer to the 9-pin interface. The result of further promotion of this habit is that nowadays people use DBxx to represent D-type interfaces, and the number xx refers to the number of pins of the interface.

Common DB interfaces on computers include:

Serial communication interface RS232 9-pin -- DB9

Display VGA 15-pin -- DB15

Parallel printer LPT 25-pin -- DB25

2. RS232

RS232 refers to a communication protocol.

RS232 has the following electrical characteristics:

1) The maximum distance for RS-232 serial communication is 50 feet

2) RS232 can achieve bidirectional transmission and full duplex communication, with a maximum transmission rate of 20kbps

3) The digital quantity transmitted on RS-232C adopts negative logic and is symmetrical with the ground.

4) Logic 1: -3 ~ -15V,  logic 0: +3~ +15V

Different encoding mechanisms cannot be mixed. For example, RS-232-C cannot be directly connected to RS-422 or RS-485 interfaces. There are specialized protocol converters available on the market that must be connected through the converter.

Our Premier Cable provides different angle DB9 serial RS232 RS485 RS422 cable for chosse: 45° Angle, 90° Angle, Left Angle, Right Angle, Up Angle, Down Angle. Whatever you are looking for, you can find it out on our Premier Cable. Leave us message now for your customized.