Question

我想确认我的消息已经通过socketCAN库保存在CAN总线上了。当使用recvmsg（）函数时，socketCAN文档描述了这种可能性，我对其实现有疑问。

我要实现的功能是确认我的消息赢得了仲裁过程。

Answer 1

我认为提到recvmsg(2)是指SocketCAN文档的以下段落：

MSG_CONFIRM: set when the frame was sent via the socket it is received on.
      This flag can be interpreted as a 'transmission confirmation' when the
      CAN driver supports the echo of frames on driver level, see 3.2 and 6.2.
      In order to receive such messages, CAN_RAW_RECV_OWN_MSGS must be set.

这里的关键词是“ CAN驱动程序支持驱动程序级别上的帧回显”。，因此必须首先确保。下一步，需要启用相应的标志。最后，这种确认与 arbitration 。当一个帧失去仲裁时，一旦总线空闲，控制器就会尝试重新传输它。

Answer 2

我认为您可以在PC上使用命令“ candump can0 / can1”，它将显示在给定的CAN接口上收到的CAN数据包。

Usage: candump [options] <CAN interface>+
  (use CTRL-C to terminate candump)

Options: -t <type>   (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date)
         -c          (increment color mode level)
         -i          (binary output - may exceed 80 chars/line)
         -a          (enable additional ASCII output)
     -b <can>    (bridge mode - send received frames to <can>)
     -B <can>    (bridge mode - like '-b' with disabled loopback)
     -u <usecs>  (delay bridge forwarding by <usecs> microseconds)
     -l          (log CAN-frames into file. Sets '-s 2' by default)
     -L          (use log file format on stdout)
     -n <count>  (terminate after receiption of <count> CAN frames)
     -r <size>   (set socket receive buffer to <size>)

确认消息已使用socketCAN发送到CAN总线

2 个答案: