Set up your CAN device

List your CAN devices

Note

You can also list your CAN interfaces with the script show-can-devices.sh or

Your can have physical or virtual CAN interfaces or both. Virtual CAN interfaces don’t require a device driver. They can be created on any Linux system and just emulate CAN interfaces. This is a great way to test CAN software without a CAN interface card.

Enter the following command:

ip link show type vcan; ip link show type can

If virtual CAN interfaces are set up, the output looks like this:

4: vcan0: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/can
5: vcan1: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/can
6: vcan2: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/can
7: vcan3: <NOARP,UP,LOWER_UP> mtu 72 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/can

If physical CAN interfaces are set up, the output looks like this:

3: can0: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/can
4: can1: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/can
5: can2: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/can
6: can3: <NOARP,UP,LOWER_UP> mtu 16 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
    link/can

Set up your CAN interfaces

Set up your device driver

You need to have a CAN device driver installed for your CAN interface. Some CAN interface cards however, work with the standard drivers of the Linux Kernel.

The standard kernel also contains drivers for a virtual CAN interface, here a CAN interface is only emulated.

Initalization of physical CAN interfaces

Note

You can load the driver and initialize your physical CAN interfaces with the script init-can.sh.

First you may have to load a driver for your CAN bus interface. Here is a short list of drivers socan was tested with, depending on your CAN interface hardware your driver name may be different:

PCAN-PCI Express FD: peak_pciefd
PCAN-USB: peak_usb
USB2CAN-Cable: not needed, driver is loaded automatically
Virtual CAN Bus interface: vcan

If you download and build the PEAK-System CAN Bus driver from source, it’s name is “pcan”.

First see if your CAN driver is loaded (replace ‘DRIVER’ with the name of the driver you need):

lsmod | grep DRIVER

If the command shows no output, load the driver with:

sudo modprobe DRIVER

and repeat the ‘lsmod’ command.

Now list all CAN devices:

ip link show type can

For each CAN device do:

sudo ip link set down DEVICE

Set the bit rate (For 1MBit use ‘1000000’ for BITRATE) and set the transmission queue to 1000:

sudo ip link set DEVICE type can bitrate BITRATE
sudo ip link set DEVICE txqueuelen 1000

Now bring the device up:

sudo ip link set up DEVICE

Initalization of virtual CAN interfaces

Note

You can also initialize your virtual CAN interfaces with the script init-can.sh.

First see if your CAN driver is loaded:

lsmod | grep vcan

If the command shows no output, load the driver with:

sudo modprobe vcan

and repeat the ‘lsmod’ command.

Now list all CAN devices:

ip link show type vcan

If there are none shown or you want to add an additional virtual CAN interface ‘vcan<N>’ where N is a non negative integer (e.g. ‘vcan2’) enter:

sudo ip link add dev vcan<N> type vcan

now bring the device up:

sudo ip link set up vcan<N>

Linking of virtual CAN interfaces

Note

You can also link your virtual CAN interfaces with the script link-vcan-devices.sh.

First show, of a CAN link is already defined:

cangw -L

If the output looks like this:

cangw -A -s vcan1 -d vcan0 -e # 0 handled 0 dropped 0 deleted
cangw -A -s vcan0 -d vcan1 -e # 0 handled 0 dropped 0 deleted

the link (here between vcan0 and vcan1) is already defined.

If the link is not defined, you can add a link between two interfaces DEVICE1 and DEVICE2 (e.g. ‘vcan0’ and ‘vcan1’) like this:

sudo cangw -A -s DEVICE1 -d DEVICE2 -e
sudo cangw -A -s DEVICE2 -d DEVICE1 -e

You may remove the same link later on with:

sudo cangw -D -s DEVICE1 -d DEVICE2 -e
sudo cangw -D -s DEVICE2 -d DEVICE1 -e

Scripts and programs provided by socan

These are described here: Programs and scripts.