Scripts#

The following modules are callable from python-can.

They can be called for example by python3 -m can.logger or can_logger.py (if installed using pip).

can.logger#

Command line help, called with --help:

$ python3 -m can.logger -h
usage: logger.py [-h] [-c CHANNEL]
                 [-i {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}]
                 [-b BITRATE] [--fd] [--data_bitrate DATA_BITRATE]
                 [-f LOG_FILE] [-a] [-s FILE_SIZE] [-v]
                 [--filter {<can_id>:<can_mask>,<can_id>~<can_mask>} [{<can_id>:<can_mask>,<can_id>~<can_mask>} ...]]
                 [--active | --passive]
                 ...

Log CAN traffic, printing messages to stdout or to a given file.

positional arguments:
  extra_args            The remaining arguments will be used for the interface
                        and logger/player initialisation. For example, `-i
                        vector -c 1 --app-name=MyCanApp` is the equivalent to
                        opening the bus with `Bus('vector', channel=1,
                        app_name='MyCanApp')

options:
  -h, --help            show this help message and exit
  -c CHANNEL, --channel CHANNEL
                        Most backend interfaces require some sort of channel.
                        For example with the serial interface the channel
                        might be a rfcomm device: "/dev/rfcomm0". With the
                        socketcan interface valid channel examples include:
                        "can0", "vcan0".
  -i {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}, --interface {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}
                        Specify the backend CAN interface to use. If left
                        blank, fall back to reading from configuration files.
  -b BITRATE, --bitrate BITRATE
                        Bitrate to use for the CAN bus.
  --fd                  Activate CAN-FD support
  --data_bitrate DATA_BITRATE
                        Bitrate to use for the data phase in case of CAN-FD.
  -f LOG_FILE, --file_name LOG_FILE
                        Path and base log filename, for supported types see
                        can.Logger.
  -a, --append          Append to the log file if it already exists.
  -s FILE_SIZE, --file_size FILE_SIZE
                        Maximum file size in bytes. Rotate log file when size
                        threshold is reached. (The resulting file sizes will
                        be consistent, but are not guaranteed to be exactly
                        what is specified here due to the rollover conditions
                        being logger implementation specific.)
  -v                    How much information do you want to see at the command
                        line? You can add several of these e.g., -vv is DEBUG
  --filter {<can_id>:<can_mask>,<can_id>~<can_mask>} [{<can_id>:<can_mask>,<can_id>~<can_mask>} ...]
                        R|Space separated CAN filters for the given CAN
                        interface: <can_id>:<can_mask> (matches when
                        <received_can_id> & mask == can_id & mask)
                        <can_id>~<can_mask> (matches when <received_can_id> &
                        mask != can_id & mask) Fx to show only frames with ID
                        0x100 to 0x103 and 0x200 to 0x20F: python3 -m
                        can.viewer -f 100:7FC 200:7F0 Note that the ID and
                        mask are always interpreted as hex values
  --active              Start the bus as active, this is applied by default.
  --passive             Start the bus as passive.

can.player#

$ python3 -m can.player -h
usage: player.py [-h] [-c CHANNEL]
                 [-i {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}]
                 [-b BITRATE] [--fd] [--data_bitrate DATA_BITRATE]
                 [-f LOG_FILE] [-v] [--ignore-timestamps] [--error-frames]
                 [-g GAP] [-s SKIP]
                 ... input-file

Replay CAN traffic.

positional arguments:
  extra_args            The remaining arguments will be used for the interface
                        and logger/player initialisation. For example, `-i
                        vector -c 1 --app-name=MyCanApp` is the equivalent to
                        opening the bus with `Bus('vector', channel=1,
                        app_name='MyCanApp')
  input-file            The file to replay. For supported types see
                        can.LogReader.

options:
  -h, --help            show this help message and exit
  -c CHANNEL, --channel CHANNEL
                        Most backend interfaces require some sort of channel.
                        For example with the serial interface the channel
                        might be a rfcomm device: "/dev/rfcomm0". With the
                        socketcan interface valid channel examples include:
                        "can0", "vcan0".
  -i {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}, --interface {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}
                        Specify the backend CAN interface to use. If left
                        blank, fall back to reading from configuration files.
  -b BITRATE, --bitrate BITRATE
                        Bitrate to use for the CAN bus.
  --fd                  Activate CAN-FD support
  --data_bitrate DATA_BITRATE
                        Bitrate to use for the data phase in case of CAN-FD.
  -f LOG_FILE, --file_name LOG_FILE
                        Path and base log filename, for supported types see
                        can.LogReader.
  -v                    Also print can frames to stdout. You can add several
                        of these to enable debugging
  --ignore-timestamps   Ignore timestamps (send all frames immediately with
                        minimum gap between frames)
  --error-frames        Also send error frames to the interface.
  -g GAP, --gap GAP     <s> minimum time between replayed frames
  -s SKIP, --skip SKIP  <s> skip gaps greater than 's' seconds

can.viewer#

A screenshot of the application can be seen below:

_images/viewer.png

The first column is the number of times a frame with the particular ID that has been received, next is the timestamp of the frame relative to the first received message. The third column is the time between the current frame relative to the previous one. Next is the length of the frame, the data and then the decoded data converted according to the -d argument. The top red row indicates an error frame. There are several keyboard shortcuts that can be used with the viewer script, they function as follows:

  • ESCAPE - Quit the viewer script

  • q - as ESCAPE

  • c - Clear the stored frames

  • s - Sort the stored frames

  • h - Toggle highlighting of changed bytes in the data field - see the below image

  • SPACE - Pause the viewer

  • UP/DOWN - Scroll the viewer

_images/viewer_changed_bytes_highlighting.png

A byte in the data field is highlighted blue if the value is different from the last time the message was received.

Command line arguments#

By default the can.viewer uses the SocketCAN interface. All interfaces are supported and can be specified using the -i argument or configured following Configuration.

The full usage page can be seen below:

$ python3 -m can.viewer -h
Usage: python3 -m can.viewer [-c CHANNEL]
                             [-i {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}]
                             [-b BITRATE] [--fd] [--data_bitrate DATA_BITRATE]
                             [-h] [--version]
                             [-d '{<id>:<format>,<id>:<format>:<scaling1>:...:<scalingN>,file.txt}',)]
                             [-f ('{<can_id>:<can_mask>,<can_id>~<can_mask>}',]
                             [-v]
                             'extra_args',

A simple CAN viewer terminal application written in Python

positional arguments:
  extra_args            The remaining arguments will be used for the interface
                        and logger/player initialisation. For example, `-i
                        vector -c 1 --app-name=MyCanApp` is the equivalent to
                        opening the bus with `Bus('vector', channel=1,
                        app_name='MyCanApp')

options:
  -c, --channel CHANNEL
                        Most backend interfaces require some sort of channel.
                        For example with the serial interface the channel
                        might be a rfcomm device: "/dev/rfcomm0". With the
                        socketcan interface valid channel examples include:
                        "can0", "vcan0".
  -i, --interface {canalystii,cantact,etas,gs_usb,iscan,ixxat,kvaser,neousys,neovi,nican,nixnet,pcan,robotell,seeedstudio,serial,slcan,socketcan,socketcand,systec,udp_multicast,usb2can,vector,virtual}
                        Specify the backend CAN interface to use. If left
                        blank, fall back to reading from configuration files.
  -b, --bitrate BITRATE
                        Bitrate to use for the CAN bus.
  --fd                  Activate CAN-FD support
  --data_bitrate DATA_BITRATE
                        Bitrate to use for the data phase in case of CAN-FD.

Optional arguments:
  -h, --help            Show this help message and exit
  --version             Show program's version number and exit
  -d, --decode ('{<id>:<format>,<id>:<format>:<scaling1>:...:<scalingN>,file.txt}',)
                        Specify how to convert the raw bytes into real values.
                        The ID of the frame is given as the first argument and the format as the second.
                        The Python struct package is used to unpack the received data
                        where the format characters have the following meaning:
                              < = little-endian, > = big-endian
                              x = pad byte
                              c = char
                              ? = bool
                              b = int8_t, B = uint8_t
                              h = int16, H = uint16
                              l = int32_t, L = uint32_t
                              q = int64_t, Q = uint64_t
                              f = float (32-bits), d = double (64-bits)
                        Fx to convert six bytes with ID 0x100 into uint8_t, uint16 and uint32_t:
                          $ python3 -m can.viewer -d "100:<BHL"
                        Note that the IDs are always interpreted as hex values.
                        An optional conversion from integers to real units can be given
                        as additional arguments. In order to convert from raw integer
                        values the values are divided with the corresponding scaling value,
                        similarly the values are multiplied by the scaling value in order
                        to convert from real units to raw integer values.
                        Fx lets say the uint8_t needs no conversion, but the uint16 and the uint32_t
                        needs to be divided by 10 and 100 respectively:
                          $ python3 -m can.viewer -d "101:<BHL:1:10.0:100.0"
                        Be aware that integer division is performed if the scaling value is an integer.
                        Multiple arguments are separated by spaces:
                          $ python3 -m can.viewer -d "100:<BHL" "101:<BHL:1:10.0:100.0"
                        Alternatively a file containing the conversion strings separated by new lines
                        can be given as input:
                          $ cat file.txt
                              100:<BHL
                              101:<BHL:1:10.0:100.0
                          $ python3 -m can.viewer -d file.txt
  -f, --filter ('{<can_id>:<can_mask>,<can_id>~<can_mask>}',)
                        Space separated CAN filters for the given CAN interface:
                              <can_id>:<can_mask> (matches when <received_can_id> & mask == can_id & mask)
                              <can_id>~<can_mask> (matches when <received_can_id> & mask != can_id & mask)
                        Fx to show only frames with ID 0x100 to 0x103 and 0x200 to 0x20F:
                              python3 -m can.viewer -f 100:7FC 200:7F0
                        Note that the ID and mask are always interpreted as hex values
  -v                    How much information do you want to see at the command
                        line? You can add several of these e.g., -vv is DEBUG

Shortcuts: 
        +---------+-------------------------------+
        |   Key   |       Description             |
        +---------+-------------------------------+
        | ESQ/q   | Exit the viewer               |
        | c       | Clear the stored frames       |
        | s       | Sort the stored frames        |
        | h       | Toggle highlight byte changes |
        | SPACE   | Pause the viewer              |
        | UP/DOWN | Scroll the viewer             |
        +---------+-------------------------------+

can.logconvert#

$ python3 -m can.logconvert -h
usage: logconvert.py [-h] [-s FILE_SIZE] INFILE OUTFILE

Convert a log file from one format to another.

positional arguments:
  INFILE                Input filename. The type is dependent on the suffix,
                        see can.LogReader.
  OUTFILE               Output filename. The type is dependent on the suffix,
                        see can.Logger.

options:
  -h, --help            show this help message and exit
  -s FILE_SIZE, --file_size FILE_SIZE
                        Maximum file size in bytes. Rotate log file when size
                        threshold is reached.