Can specifications, Can frame configurations – FUJITSU CAN-Motor Board MB91F267N User Manual

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4. High-speed version and low-speed version

There are two CAN specifications with different communication speeds. One of them is

High-speed-CAN. High-speed-CAN is standardized as ISO11898 and its maximum and

minimum communication speeds are 1 Mbits/sec and 125 kbits/sec. The other is

Low-speed-CAN. Low-speed-CAN is standardized as ISO11519 and its maximum

communication rate is 125 kbits/sec. The communication speeds currently popular are, in order

of rates, 500 kbits/sec, 250 kbits/sec, 125 kbits/sec, 83.3 kbits/sec, 33.3 kbits/sec and so forth.

5. Node control with error counters against errors

CAN supports five types of error detection. Each node has error counters. If an error occurs,

either counter is increased by a specified count. On the contrary, when communication is

successful, the counter is decreased by a specified constant. The communication status of each

node is determined by the values of the error counters. This mechanism serves to limit

communication by node.

5.2

CAN specifications

This section provides brief descriptions of the CAN specifications.

For more information about the specifications, access the web site of the CAN promoting organization

CiA (CAN in Automation) (

) and make a registration; you can get the

specifications.

5.2.1

CAN frame configurations

This section describes frames that are the fundamental communication unit of CAN.

CAN provides four types of frames, which are respectively named the data frame, remote frame, error