canopen 0.4.0

CANopen stack implementation

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

Features

• NMT master

• SDO client

• PDO producer/consumer

• SYNC producer

• EMCY consumer

Installation

Install from PyPI using pip:

$ pip install canopen

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/stable/

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

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 a python-can bus
# (see https://python-can.readthedocs.io/en/latest/bus.html).
network.connect(channel=0, bustype='kvaser', 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()
# Transmit SYNC every 100 ms
network.sync.start(0.1)

# Change state to operational (NMT start)
network[6].nmt.state = 'OPERATIONAL'
network[7].nmt.state = 'OPERATIONAL'

# Read a value from Tx PDO 1
node.pdo.tx[1].wait_for_reception()
speed = node.pdo.tx[1]['ApplicationStatus.ActualSpeed'].phys

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

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

• SDO block transfer

• TIME

• XDD support