Transmission speed

The speed with which the bits are transferred over the bus line are mainly dependent upon

• the length of the bus line,
• the length of the branch lines to the CAN  stations,
• the quality of the bus lines and the contact plug,
• the design of the bus line (twisted, single or twin wire bus),
• the design of the bus connection, and
• the type and the strength of outside interferences.

 

The transmission speed is given in the form of transmission rate. This gives the maximum number of bits that can be transferred in one second.
Therefore the unit of the transmission rate is "bits per second", i.e. "bits / s".

The time a single bit needs for the transmission (the so-called "bit time") has an important role in calculating the transmission rate. Since these bit times are only fractions of a second, the bit time is given in "microseconds" (µs). Remember: A microsecond is a millionth of a second.

If the bit time is known then the transmission rate is easily calculated:

x: trasnmission rate b: bit tb: bit time