CANopen for Python

A Python implementation of the CANopen standard. The aim of the project is to support the most common parts of the CiA 301 standard for a master node wrapped in a Pythonic interface.

The library supports Python 2.7 and 3.3+ and runs on Windows, Linux and Mac.

Features

Object Dictionary from EDS
NMT master
SDO client
PDO producer/consumer
SYNC producer
EMCY consumer
TIME producer

Installation

Install from PyPI using pip:

$ pip install canopen

Install from latest master on GitHub:

$ pip install https://github.com/christiansandberg/canopen/archive/master.zip

If you want to be able to change the code while using it, clone it then install it in develop mode:

$ git clone https://github.com/christiansandberg/canopen.git
$ cd canopen
$ pip install -e .

Documentation

Documentation can be found on Read the Docs:

http://canopen.readthedocs.io/en/latest/

It can also be generated from a local clone using Sphinx:

$ python setup.py build_sphinx

Hardware support

This library supports multiple hardware and drivers through the python-can package. At the time of writing this includes:

SocketCAN on Linux
Kvaser
Peak CAN
IXXAT
USB2CAN
NI-CAN
neoVI

It is also possible to integrate this library with a custom backend.

Quick start

Here are some quick examples of what you can do:

import canopen

# Start with creating a network representing one CAN bus
network = canopen.Network()

# Add some nodes with corresponding Object Dictionaries
node = network.add_node(6, '/path/to/object_dictionary.eds')
network.add_node(7, '/path/to/object_dictionary.eds')

# Connect to the CAN bus
# Arguments are passed to python-can's can.interface.Bus() constructor
# (see https://python-can.readthedocs.io/en/latest/bus.html).
network.connect(bustype='socketcan', channel='can0')
# network.connect(bustype='kvaser', channel=0, bitrate=250000)
# network.connect(bustype='pcan', channel='PCAN_USBBUS1', bitrate=250000)
# network.connect(bustype='ixxat', channel=0, bitrate=250000)
# network.connect(bustype='nican', channel='CAN0', bitrate=250000)

# Read a variable using SDO
device_name = node.sdo['Manufacturer device name'].raw
vendor_id = node.sdo[0x1018][1].raw

# Write a variable using SDO
node.sdo['Producer heartbeat time'].raw = 1000

# Read PDO configuration from node
node.pdo.read()
# Re-map TxPDO1
node.pdo.tx[1].clear()
node.pdo.tx[1].add_variable('Application Status', 'Status All')
node.pdo.tx[1].add_variable('Application Status', 'Actual Speed')
node.pdo.tx[1].trans_type = 254
node.pdo.tx[1].event_timer = 10
node.pdo.tx[1].enabled = True
# Save new PDO configuration to node
node.pdo.save()

# Transmit SYNC every 100 ms
network.sync.start(0.1)

# Change state to operational (NMT start)
node.nmt.state = 'OPERATIONAL'

# Read a value from TxPDO1
node.pdo.tx[1].wait_for_reception()
speed = node.pdo.tx[1]['Application Status.Actual Speed'].phys

# Disconnect from CAN bus
network.sync.stop()
network.disconnect()

Debugging

If you need to see what's going on in better detail, you can increase the logging level of this library and possibly for python-can as well:

import logging
logging.getLogger('canopen').setLevel(logging.DEBUG)
logging.getLogger('can').setLevel(logging.DEBUG)

TODO

There are a lot of things that still needs implementing and fixing. Pull requests are most welcome!

More unit test coverage
Period transmits using python-can cyclic API
XDD support

Jimhui/canopen