Lenze E84DGFCC - Manual (Page 68)

Communication manual 8400 motec CANopen
Monitoring
Integrated error detection
68
L
EDS84DMOTCAN EN 3.0 - 11/2011
10.2 Integrated error detection
If a node detects an error, it rejects the CAN telegram bits received so far and transmits an
error flag. The error flag consists of 6 consecutive bits with the same logic value.
The following errors are detected:
Bit error
The sending node monitors the bus and interrupts the transmission if it receives a different
logic value than the value transmitted. With the next bit, the sending node starts the
transmission of an error flag.
In the arbitration phase, the sender only detects a bit error if a dominantly sent bit is
received as a recessive bit. In the ACK slot as well, the dominant overwriting of a recessive
bit is not indicated as a bit error.
Stuff-bit error
If more than 5 consecutive bits before the ACK delimiter in the CAN telegram have the
same logic value, the previously transmitted telegram will be rejected and an error flag will
be sent with the next bit.
CRC error
If the CRC checksum received does not correspond to the checksum calculated in the CAN
chip, the CAN controller sends an error flag after the ACK delimiter, and the previously
transmitted telegram is invalidated.
Acknowledgement error
If the ACK slot which is sent recessively by the transmitting node is not overwritten
dominantly by a receiver, the transmitting node aborts the transmission. The transmitting
node invalidates the telegram transmitted and sends an error flag with the next bit.
Format error
If a dominant bit is detected in the CRC delimiter, in the ACK delimiter or in the first 6 bits
of the EOF field, the telegram received is rejected and an error flag is sent with the next bit.