Skip to main content

Bit rate, baud rate and character time at 9600

Short answer

Bit rate is bits per second, baud rate is signal changes per second; for binary signaling they are equal. A 7-data-bit, 1-start, 2-stop frame has 10 bits. At 9600 baud, character time = 10/9600 = 1.0417 ms, giving 960 characters/s. Sending the word 'Engineer' (8 characters) requires 8 × 1.0417 = 8.33 ms.

Define bit rate and baud rate. Determine a character transmission rate using asynchronous serial data transfer method at baud rate 9600. Suppose a character has 7 bits data, one bit start bit, two bits stop bit and none parity. Calculate the time required to send a word: Engineer.

Definitions

  • Bit rate: number of bits transmitted per second (bps).
  • Baud rate: number of signal changes (signalling elements or symbols) per second. For binary signalling, as in RS-232 where each element carries one bit, baud rate = bit rate. With multi-level coding, bit rate = baud rate x bits per symbol.

Character frame

1 start + 7 data + 0 parity + 2 stop = 10 bits per character.

Calculation at 9600 baud (9600 bps)

 Bit time        = 1 / 9600            = 0.10417 ms
 Character time  = 10 x 0.10417 ms     = 1.0417 ms
 Character rate  = 9600 / 10           = 960 characters/s
 "Engineer" has 8 characters
 Time            = 8 x 1.0417 ms       = 8.33 ms

Answer: character transmission rate = 960 characters/s; time to send "Engineer" = 8.33 ms (80 bits / 9600 bps).

✓ Answer checked by Claude Sonnet 5.5

Related questions

All Instrumentation II chapter 3 questions →