How does candump display send, receive and timestamp?

As the title says, I used the command candump can0 can1 to watch frames on the CAN bus, but I can't distinguish which frames are received and which are sent. Sometimes I need the timestamp of received frames to analyze problems.
Accordingly, how is the time stamp printed in tcpdump?
Tcpdump prints out a description of the contents of packets on a network interface that match the Boolean expression; the description is preceded by a time stamp, printed, by default, as hours, minutes, seconds, and fractions of a second since midnight.
Consequently, how are time stamps stored in a file? The time stamp precision supported by a specific capture file format differs widely and varies from one second “0” to one nanosecond “0.123456789”. Most file formats store the time stamps with a fixed precision (e.g. microseconds), while some file formats are even capable of storing the time stamp precision itself (whatever the benefit may be).
Moreover, how does the timestamp function work in PostgreSQL?
Date and time: We can use any date and time to display the format of timestamp. If we have used the only date, then it will display a date and time. Current timestamp: This function is used to select the current date and time in PostgreSQL. If we want to use the current date and time, then we have to use a current timestamp function in PostgreSQL.
Indeed, how to change the time stamp format in Wireshark?
You can adjust the way Wireshark displays the time stamp data in the packet list, see the “Time Display Format” item in the Section 3.7, “The “View” Menu” for details. While reading or writing capture files, Wireshark converts the time stamp data between the capture file format and the internal format as required.

20 Similar Question Found

What kind of id does candump show me?

In a nutshell, I want candump to show me ONLY frames with IDs 0x00200200 or 0x255. But this gives ALL frames, and each frame is shown twice. i.e. the output of:

Where are the can messages stored in candump?

The definition are most commonly stored into a .dbc file, a proprietary file format that many tools supports. These file describe how to interpret CAN messages, but also list the nodes in the network and what message ID is attributed to each node.

How to dump can bus traffic in candump?

candump[options] <CAN interface>+ DESCRIPTION¶ candump - dump CAN bus traffic. (use CTRL-C to terminate candump) OPTIONS¶ -t<type> (timestamp: (a)bsolute/(d)elta/(z)ero/(A)bsolute w date) -H (read hardware timestamps instead of system timestamps) -c (increment color mode level) -i

How to log can utils in candump ( 1 )?

(log CAN-frames into file. Sets '-s 2' by default) (use log file format on stdout) (terminate after reception of <count> CAN frames) (set socket receive buffer to <size>) (Don't exit if a "detected" can device goes down. (monitor dropped CAN frames) (dump CAN error frames in human-readable format)

Do you need a timestamp for candump?

Sometimes I need the timestamp of received frames to analyze problems. I don`t know if candump supports these. As said in the comments, the CAN protocol does not keep tracks of sender/receiver. The only data identifying a message is the message ID. In a common CAN network, each devices is assigned specifc ID for transmission and reception.

Do you need gpl for candump.c at master?

* documentation and/or other materials provided with the distribution. * 3. Neither the name of Volkswagen nor the names of its contributors * without specific prior written permission. * GPL apply INSTEAD OF those given above.

How to set comma separated filters in candump?

Comma separated filters can be specified for each given CAN interface. (matches when <received_can_id> & mask == can_id & mask) (matches when <received_can_id> & mask != can_id & mask) (set error frame filter, see include/linux/can/error.h) (join the given CAN filters - logical AND semantic)

Why is the output of candump shown twice?

But this gives ALL frames, and each frame is shown twice. i.e. the output of: Aside from the filter not behaving like I expected and passing through 0x256, the fact that it shows up twice suggests that this frames is actually matched by both filters, which makes even less sense to me.

How to use candump on a canbus?

$ candump -l can0 Disabled standard output while logging. Enabling Logfile 'candump-2017-05-19_112441.log' Cansend is used to transmit individual frames directly onto the CANbus.

How to include comma separated filters in candump?

Comma separated filters can be specified for each given CAN interface: (matches when <received_can_id> & mask == can_id & mask) (matches when <received_can_id> & mask != can_id & mask) (set error frame filter, see include/linux/can/error.h) (join the given CAN filters - logical AND semantic)

Is there a copyright on candump.c file?

* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT * DAMAGE. fprintf (stderr, " -l (log CAN-frames into file.

Why does candump match the mask twice in linux?

Aside from the filter not behaving like I expected and passing through 0x256, the fact that it shows up twice suggests that this frames is actually matched by both filters, which makes even less sense to me. Can anyone explain why this is happening, and perhaps show me the correct way to do it? Now, when the mask is 0, every CAN ID will match it.

Is there a way to record a candump file?

Sent data to the vcan interface using cansend and cangen, with success (verified with candump). Recorded a candump file from vcan0 when running cangen. Recorded files with absolute timestamps (-t a) and without. Tried using canplayer to reproduce the file.

Is there a way to replay a candump file?

Recorded files with absolute timestamps (-t a) and without. Tried using canplayer to reproduce the file. Tried using several arguments, no avail. canplayer just returns immediately without any complaint. If I mess up the the file or arguments it complains.

How to set the can id in candump?

From the help of candump: <can_id>:<can_mask> (matches when <received_can_id> & mask == can_id & mask) Now, when the mask is 0, every CAN ID will match it. So the can_id has no real effect, this is why all messages pass, each required bit in the can id should be set to 1 in the mask.

How to set error frame filter in candump?

(set error frame filter, see include/linux/can/error.h) (join the given CAN filters - logical AND semantic) CAN IDs, masks and data content are given and expected in hexadecimal values.

What is the output format of candump on a raspberry pi?

Output format of the Linux utility candump. This file should have an extension *.log. You can use Raspberry Pi, Orange Pi or any other Linux PC with can interface and can-utils software installed. How to set up Pi for CAN-bus operation you can read there. 11bit format example:

How to decode can frames in candump linux?

Decode CAN frames captured with the Linux program candump. Alternatively, the decoded message can be printed on a single line: The plot subcommand is similar to the decode subcommand but messages are visualized using matplotlib instead of being printed to stdout.

Why is jetson tx2 not showing in candump?

For the first testing, we did not connect any nodes (not even the CAN board) to the jetson. Usually it shouldn’t be a problem as the Jetson itself doesn’t appear in the Candump. Your commands do not work, because we have to use “sudo ip link” in order to set up the network. Without sudo ip link we get:

How is canutilslogwriter compatible with candump-l?

[docs] class CanutilsLogWriter(BaseIOHandler, Listener): """Logs CAN data to an ASCII log file (.log). This class is is compatible with "candump -L". If a message has a timestamp smaller than the previous one (or 0 or None), it gets assigned the timestamp that was written for the last message.