CAN (Control Area Network)

There are two types of CAN

1. CAN 2.0 A which is a standard 11 bit identifier

2. CAN 2.0 B which is a extended 29 bit identifier (These are essentially used on vehicles)

There two speed standards for this 

ISO- 11898-2 = High speed up to 1 Mbps

ISO- 11898-3 = Low speed up to 125 Kbps

Mostly they used 1 Mbps high speed up to 40 Meters which is not necessarily enough for a long trunks and the slower speed is 125 Kbps up to 500 Meters. There are other speeds also.

                 Now you need to know control area network communication and why it is CAN message adopted over regular (i.e., digital On/Off method)?

This is how CAN works

1. CAN uses differential method.
2. When nothing is transmitted on CAN line then both CAN high and CAN low is sit around 2.5 Volts, you can measured it with multimeter.
3. When it transmitting then CAN high goes to 3.5 volts and CAN low comes down to 0 volts and receiving end will look at differential voltage between CAN high and CAN low.


Note:-
We also say that CAN is faster because its switching time is less. It means it takes less time to CAN high and CAN low.