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Baud rate is about the speed of bit slots in the channel or symbols. Bit rate is the rate at which actual data is transmitted. Put another way, baud rate is what you see when you look at a scope ...
Answer
#4: Post edited
by
Olin Lathrop
·
2020-11-30T19:00:35Z (almost 4 years ago)
- <i><b>Baud rate</b></i> is about the speed of bit slots in the channel or <i>symbols</i>. <i><b>Bit rate</b></i> is the rate at which actual data is transmitted.
- Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other.
- The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate.
- However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate.
Consider the common UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k/s, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.
- <i><b>Baud rate</b></i> is about the speed of bit slots in the channel or <i>symbols</i>. <i><b>Bit rate</b></i> is the rate at which actual data is transmitted.
- Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other.
- The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate.
- However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate.
- Consider the common UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k/s, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.
- <hr>
- @TonyStewart wrote:
- <blockquote>Can you give an example where Baud Rate is higher than Bit Rate?</blockquote>
- I did. See previous paragraph.
#3: Post edited
by
Olin Lathrop
·
2020-11-24T14:32:12Z (almost 4 years ago)
- <i><b>Baud rate</b></i> is about the speed of bit slots in the channel or <i>symbols</i>. <i><b>Bit rate</b></i> is the rate at which actual data is transmitted.
- Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other.
- The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate.
- However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate.
Consider the basic UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.
- <i><b>Baud rate</b></i> is about the speed of bit slots in the channel or <i>symbols</i>. <i><b>Bit rate</b></i> is the rate at which actual data is transmitted.
- Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other.
- The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate.
- However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate.
- Consider the common UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k/s, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.
#2: Post edited
by
Olin Lathrop
·
2020-11-24T14:29:50Z (almost 4 years ago)
<i>Baud rate</i> is about the speed of bit slots in the channel or <i>symbols</i>. <i>Bit rate</i> is the rate at which actual data is transmitted.- Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other.
- The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate.
- However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate.
- Consider the basic UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.
- <i><b>Baud rate</b></i> is about the speed of bit slots in the channel or <i>symbols</i>. <i><b>Bit rate</b></i> is the rate at which actual data is transmitted.
- Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other.
- The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate.
- However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate.
- Consider the basic UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.
#1: Initial revision
by
Olin Lathrop
·
2020-11-24T14:28:14Z (almost 4 years ago)
<i>Baud rate</i> is about the speed of bit slots in the channel or <i>symbols</i>. <i>Bit rate</i> is the rate at which actual data is transmitted. Put another way, baud rate is what you see when you look at a scope trace of a communication signal. Bit rate is how fast data gets from one end to the other. The bit rate can be both higher and lower than the baud rate due to encoding and packaging schemes. Modern high speed protocols do various fancy things to encode more than one bit of data into each symbol, so the bit rate is often higher than the baud rate. However, for most "ordinary" protocols (UART, CAN, IIC, SPI for example), some of the bit slots are used to delimit and package the information, so the bit rate is lower than the baud rate. Consider the basic UART protocol of 115.2 kBaud, 8 data bits, no parity, and 1 stop bit. Each character requires 10 bit slots to send: 1 start bit, 8 actual data bits, and 1 stop bit. Since the baud rate is 115.2 k, each bit slot is 8.68 µs long. A whole character therefore takes 86.8 µs to transmit. A total of 8 payload bits are transported during that time, so the bit rate is (8 bits)/(86.8 µs) = 92.2 kBits/s.