Baud rate refers to the speed of serial communication, measured in symbols per second. In standard binary communication interfaces used for industrial equipment, such as RS-232C, one symbol typically represents one bit. Therefore, the baud rate is effectively equivalent to bps (bits per second).
Importance in Asynchronous Communication
In asynchronous serial communication, there is no shared clock signal between the transmitter (e.g., a computer) and the receiver (e.g., a programmable DC power supply). Both devices must rely on a pre-agreed timing to interpret data correctly.
- Matching Settings: The baud rate must be set to the exact same value on both the controller and the device.
- Mismatched Rates: If settings differ (e.g., 9600 vs. 19200), the receiver will misinterpret the signal timing, resulting in communication failure.
Common Settings
Standard baud rates include 4800, 9600, 19200, 38400, 57600, and 115200 bps. While USB and Ethernet are widely used today, RS-232C remains a standard choice for integrating high-voltage power supplies and measurement instruments due to its reliability in industrial environments.