Rainbow Electronics CAN интерфейс - Manual (Page 21)

BOSCH
ROBERT BOSCH GmbH, Postfach 50, D-7000 Stuttgart 1
Sep. 1991
Part A - page 19
For stations which are not ’error passive’ or have been RECEIVER of the previous
message:
For ’error passive’ stations which have been TRANSMITTER of the previous message:
INTERMISSION
consists of three ’recessive’ bits.
During INTERMISSION no station is allowed to start transmission of a DATA FRAME
or REMOTE FRAME. The only action to be taken is signalling an OVERLOAD
condition.
BUS IDLE
The period of BUS IDLE may be of arbitrary length. The bus is recognized to be free
and any station having something to transmit can access the bus. A message, which is
pending for transmission during the transmission of another message, is started in the
first bit following INTERMISSION.
The detection of a ’dominant’ bit on the bus is interpreted as a START OF FRAME.
SUSPEND TRANSMISSION
After an ’error passive’ station has transmitted a message, it sends eight ’recessive’
bits following INTERMISSION, before starting to transmit a further message or
recognizing the bus to be idle. If meanwhile a transmission (caused by another station)
starts, the station will become receiver of this message.
Frame
Bus Idle
INTERFRAME SPACE
Intermission
Frame
Frame
Bus Idle
INTERFRAME SPACE
Intermission
Frame
Suspend Transmission
Interframe Space