Information about RS232 Serial communication

Serial Communication

Data can be transferred between devices in serial or parallel. Serial communication stream data one bit a time and can use down to only one wire. Parallel communication send data in bigger lumps and all bits arrive at the same time, this kind of communication uses several wires, usually 8 or more, to send the data.

RS-232 is a standard for serial communication defined by Electronic Industries Association in 1969.

Serial Port

DB-9 or DB-25 connectors are used for serial ports. They might also be called D-sub. DB-9 has 9 pins and DB-25 25 pins.

Baudrate

The baudrate specifies at which rate bits are transmitted. It specifies the number of signal or symbol changes that occur per second.

If two devices uses different baudrates they aren't communicating at the same speed and it will not work.

Below are standard baudrates listed:

• 50
• 75
• 110
• 134
• 150
• 200
• 300
• 600
• 1200
• 2400
• 4800
• 9600
• 19.2K
• 38.4K
• 57.6K
• 115.2K

DTE and DCE

DTE stands for Data Terminal Equipment. DCE stands for Data Communication Equipment.

External references:

• Serial Port Object Properties
• Commfront 3 easy steps
• Bitrate vs Baudrate