使用 socketCAN 确认消息被发送到 CAN 总线

Question

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

我要实现的功能是确认我的消息在仲裁过程中获胜

Answer 1

我想提到 recvmsg(2) 你参考了 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“当 CAN driver支持driver level的帧回显，所以首先要确保，接下来需要开启相应的flags。最后，这样的确认有与 仲裁无关 。当帧失去仲裁时，一旦总线空闲，控制器就会尝试 re-transmit 它。

Answer 2

我想你可以在你的电脑上使用命令"candump can0/can1"，它会显示在给定的 CAN 接口上接收到的 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>)

使用 socketCAN 确认消息被发送到 CAN 总线

Confirmation that the message was sent to the CAN bus using socketCAN

c

sockets

can-bus

socketcan

recvmsg