Rainbow Electronics CAN интерфейс - Manual (Page 12)

BOSCH
ROBERT BOSCH GmbH, Postfach 50, D-7000 Stuttgart 1
Sep. 1991
Part A - page 10
3 MESSAGE TRANSFER
3.1 Frame Types
Message transfer is manifested and controlled by four different frame types:
A DATA FRAME carries data from a transmitter to the receivers.
A REMOTE FRAME is transmitted by a bus unit to request the transmission of the
DATA FRAME with the same IDENTIFIER.
An ERROR FRAME is transmitted by any unit on detecting a bus error.
An OVERLOAD FRAME is used to provide for an extra delay between the preceding
and the succeeding DATA or REMOTE FRAMEs.
DATA FRAMEs and REMOTE FRAMEs are separated from preceding frames by an
INTERFRAME SPACE.
3.1.1 DATA FRAME
A DATA FRAME is composed of seven different bit fields:
START OF FRAME, ARBITRATION FIELD, CONTROL FIELD, DATA FIELD, CRC
FIELD, ACK FIELD, END OF FRAME. The DATA FIELD can be of length zero.
Interframe
Space Interframe
Space
Start of Frame
Arbitration Field
Control Field
Data Field
CRC Field
ACK Field
End of Frame
or
Overload
Frame
DATA FRAME
Message Transfer