What is baud rate in serial communication?
Baud rate is the number of signal units (symbols) transmitted per second in a serial communication channel. It determines the speed at which data can be transmitted between devices. For example, a baud rate of 9600 means 9600 symbols can be transmitted per second. See also our find Crosstalk Coefficient with Crosstalk Calculator.
How do I calculate character time from baud rate?
Character time is calculated by dividing the total bits per character by the baud rate. Total bits include start bit (1), data bits (7 or 8), parity bit (0 or 1), and stop bits (1 or 2). For example, with 8 data bits, no parity, 1 stop bit at 9600 baud: Character time = 10 bits / 9600 = 1.04 ms.
What affects the total polling cycle time?
Polling cycle time is affected by: request message length, response message length, slave response delay, network propagation delay, inter-message overhead, and the number of devices being polled. Each device adds one complete poll time to the total cycle.
Why is slave response delay important?
Slave response delay is the processing time a slave device needs to interpret a request and prepare its response. This varies by device complexity and can significantly impact overall communication timing, especially in networks with many devices or complex slave operations.
What baud rate should I use for my application?
Common baud rates include 9600, 19200, 38400, 57600, and 115200. Choose based on your distance requirements, noise environment, and timing needs. Higher baud rates allow faster communication but may be less reliable over long distances or in noisy environments.
How does parity affect communication timing?
Adding parity (even or odd) increases each character frame by one bit, which proportionally increases character time and overall message transmission time. While parity provides error detection, it comes at the cost of slightly slower communication.