canlib

Contents

• canlib

  • List connected devices

  • Send and receive single frame

  • Send and receive CAN FD frame

The following sections contain sample code for inspiration on how to use Kvaser Python canlib.

List connected devices

"""list_devices.py -- List all connected CAN devices

This code probes each connected device and prints information about them.

"""

import canlib


for dev in canlib.connected_devices():
    print(dev.probe_info())

Sample Output:

CANlib Channel: 0
Card Number   : 7
Device        : Kvaser Memorator Pro 2xHS v2 (channel 0)
Driver Name   : kcany7a
EAN           : 73-30130-00819-9
Firmware      : 3.24.0.722
Serial Number : 12330
CANlib Channel: 2
Card Number   : 8
Device        : Kvaser Memorator Pro 5xHS (channel 0)
Driver Name   : kcany8a
EAN           : 73-30130-00832-8
Firmware      : 3.23.0.646
Serial Number : 10028
CANlib Channel: 7
Card Number   : 0
Device        : Kvaser Virtual CAN Driver (channel 0)
Driver Name   : kcanv0a
EAN           : 00-00000-00000-0
Firmware      : 0.0.0.0
Serial Number : 0

Send and receive single frame

"""send_and_receive_can.py

Here is some basic code to send and receive a single frame.

"""


from canlib import canlib, Frame
from canlib.canlib import ChannelData


def setUpChannel(channel=0,
                 openFlags=canlib.Open.ACCEPT_VIRTUAL,
                 outputControl=canlib.Driver.NORMAL):
    ch = canlib.openChannel(channel, openFlags)
    print("Using channel: %s, EAN: %s" % (ChannelData(channel).channel_name,
                                          ChannelData(channel).card_upc_no))
    ch.setBusOutputControl(outputControl)
    # Specifying a bus speed of 250 kbit/s. See documentation
    # for more informationon how to set bus parameters.
    params = canlib.busparams.BusParamsTq(
        tq=8,
        phase1=2,
        phase2=2,
        sjw=1,
        prescaler=40,
        prop=3
    )
    ch.set_bus_params_tq(params)
    ch.busOn()
    return ch


def tearDownChannel(ch):
    ch.busOff()
    ch.close()


print("canlib version:", canlib.dllversion())
ch0 = setUpChannel(channel=0)
ch1 = setUpChannel(channel=1)
frame = Frame(
    id_=100,
    data=[1, 2, 3, 4],
    flags=canlib.MessageFlag.EXT
)
ch1.write(frame)
while True:
    try:
        frame = ch0.read()
        print(frame)
        break
    except canlib.canNoMsg:
        pass
    except canlib.canError as ex:
        print(ex)
tearDownChannel(ch0)
tearDownChannel(ch1)

Send and receive CAN FD frame

"""send_and_receive_canfd.py

Here are some minimal code to send and receive a CAN FD frame.

"""

from canlib import canlib, Frame

# Specifying an arbitration phase bus speed of 1 Mbit/s,
# and a data phase bus speed of 2 Mbit/s. See documentation
# for more information on how to set bus parameters.
params_arbitration = canlib.busparams.BusParamsTq(
    tq=40,
    phase1=8,
    phase2=8,
    sjw=8,
    prescaler=2,
    prop=23
)
params_data = canlib.busparams.BusParamsTq(
    tq=20,
    phase1=8,
    phase2=4,
    sjw=4,
    prescaler=2,
    prop=7
)

# open channel as CAN FD using the flag
ch0 = canlib.openChannel(channel=0, flags=canlib.Open.CAN_FD)
ch0.setBusOutputControl(drivertype=canlib.Driver.NORMAL)
ch0.set_bus_params_tq(params_arbitration, params_data)
ch0.busOn()

ch1 = canlib.openChannel(channel=1, flags=canlib.Open.CAN_FD)
ch1.setBusOutputControl(drivertype=canlib.Driver.NORMAL)
ch1.set_bus_params_tq(params_arbitration, params_data)
ch1.busOn()

# set FDF flag to send using CAN FD
# set BRS flag to send using higher bit rate in the data phase
frame = Frame(
    id_=100,
    data=range(32),
    flags=canlib.MessageFlag.FDF | canlib.MessageFlag.BRS
)
print('Sending', frame)
ch0.write(frame)

frame = ch1.read(timeout=1000)
print('Received', frame)

ch0.busOff()
ch1.busOff()