摘要:
An improved method for exchange of data in data processing installations, especially Controller Areas Networks (CAN), permits acknowledged and segmented transmission of data strings, of arbitrarily long length, between at least two stations in the network or other data processing installation. The method includes the transmission of the messages associated with the data by means of frames; the frames contain a header field and a data field. In the event of contention between multiple stations of the data processing installation for access to the bus connection, which frame has priority is determined by evaluating the respective header fields. In the data field of the frame, there is a control information field (58, 95) containing a message code which serves to identify the message type. The message codes distinguish among activation messages (AR, AC), data messages (DT), and acknowledgement (AK) messages. This permits transmission of data strings, of limited length, with acknowledgement. Further, the control information fields (58, 95) of certain messages contain a sequence number, a receiver status code, a message end code, and a code specifying how many data bytes are being transmitted in the frame. With this additional information, data strings of arbitrarily long length may be transmitted as segments. The receipt of the individual partial messages is confirmed by sending back an acknowledgment in each case.
摘要:
A process for the localization of defective stations in local networks which consist of several locally distributedly operating stations is proposed, particularly for use in automobiles. The process is characterized by station-internal, statistical evaluation of external and/or internal error signals. The redundancy necessary for a self-monitoring of the stations interconnected by a serial bus need not be available locally in the respective station, rather only the redundancy existing in any case in a network due to the presence of protocol-compatible stations is utilized.
摘要:
The invention is directed to a method for structuring messages for the exchange of data and/or for the synchronization of processes in data processing systems. A message includes at least elements with respect to start (start-bit, SOF), identification (also called identifier) and data with one bit field (IDE-field, IDE-bit) having at least one bit for characterizing the length of the identifier.