December 2001 Introduction 8 – 7
Data transfer rate The data transfer rate is given in bits per second.
Common transfer rates are:
110, 150, 300, 600, 1200, 2400, 4800, 9600, 19 200, 38 400, 57 600 and
115 200 bps
The time taken to transmit one bit (t
B
) can be calculated from the transfer rate:
For example, a transfer rate of 19 200 bps will have a bit duration of
t
B
= 52.083 µs. The number of characters transmitted per second can be
calculated from the transfer rate and the transmission format:
Example:
With a transmission format of one start bit, 7 data bits, two stop bits and a data
transfer rate of 300 bps, exactly 30 characters per second will be transmitted.
t
B
1
Baud rate (Bit/s)
---------------------------------------------------=
t
B
1
19200 (Bit/s)
---------------------------------------- 52 . 083 µs ==
Characters per second
Baud-Rate (Bit/s)
Number of bits per character
-------------------------------------------------------------------------------------------=
Characters per second
300 (Bit/s)
1 + 7 + 2
-------------------------------- 3 0==