Method & apparatus for data exchange in data processing installations
    1.
    发明授权
    Method & apparatus for data exchange in data processing installations 失效
    数据处理设备中数据交换的方法与装置

    公开(公告)号:US5448561A

    公开(公告)日:1995-09-05

    申请号:US947501

    申请日:1992-09-16

    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.

    摘要翻译: 在数据处理装置(尤其是控制器区域网络(CAN))中交换数据的改进方法允许在网络或其他数据处理装置中的至少两个站之间的任意长度的数据串的确认和分段传输。 该方法包括通过帧传输与数据相关联的消息; 帧包含头字段和数据字段。 在用于访问总线连接的数据处理装置的多个站之间发生争用的情况下,通过评估相应的报头字段来确定哪个帧具有优先权。 在帧的数据字段中,存在包含用于识别消息类型的消息代码的控制信息字段(58,95)。 消息代码区分激活消息(AR,AC),数据消息(DT)和确认(AK)消息。 这允许有限长度的数据串的传输与确认。 此外,某些消息的控制信息字段(58,95)包含序列号,接收者状态码,消息结束码和指定帧中正在发送多少个数据字节的码。 利用这些附加信息,任意长度的数据串可以作为段传送。 通过在每种情况下发回确认来确认各个部分消息的接收。