pysoem

library1.1.13pypypi✓ verified 86d ago

Cython wrapper for the SOEM (Simple Open EtherCAT Master) library. Provides Python bindings to control EtherCAT networks. Current version 1.1.13. Release cadence: irregular, several minor releases per year.

http-networking

pip install pysoem

github ↗package ↗docs ↗

INSTALL

IMPORT

SIG · PYSOEM

pysoem

http-networkingpythonv1.1.13

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

Master

✓ from pysoem import Master

Primary class for EtherCAT master operations.

settings

✓ from pysoem import settings

Module-level configuration object (e.g., timeouts, GIL behavior).

EMERGENCY

✓ from pysoem import EMERGENCY

Emergency message type constant.

Basic EtherCAT master setup: open interface, configure slaves, map PDOs, set operational state.

import time from pysoem import Master master = Master() master.open(os.environ.get('ETHERCAT_INTERFACE', 'eth0')) master.config_init() # Map PDOs (example) for slave in master.slaves: print(slave.name) master.config_map() master.state = 'OP' master.write_state() master.receive_processdata() time.sleep(0.1) master.close()

Debug

Known issues

breakingIn version 1.1.11, the default release_gil behavior changed. New functions and a global setting 'always_release_gil' were added. Code relying on GIL being held during SDO operations may need to explicitly set release_gil=False.

fix

Set pysoem.settings.always_release_gil = False if you need the GIL held for legacy reasons, or pass release_gil=False to individual calls.

affects: >=1.1.11

gotchaThe config_init() method may fail if called multiple times without a proper re-initialization. Bug fixed in 1.1.6, but still advisable to call config_init() only once per session.

fix

Ensure config_init() is called exactly once per master instance.

affects: >=1.1.6

gotchaProperties 'config_func' and 'setup_func' can be None if not initialized. Accessing them before assignment can cause null pointer errors (fixed in 1.1.8). Always set them before use or check for None.

fix

Set config_func and setup_func on each slave before calling config_init(), or upgrade to 1.1.8+.

affects: <1.1.8

Errors

Common errors & fixes

ModuleNotFoundError: No module named 'pysoem'

Missing installation or wrong Python environment.

fix

Run 'pip install pysoem' in the correct virtual environment. Ensure pip is up to date.

AttributeError: 'Master' object has no attribute 'config_init'

Trying to use an older version of pysoem (pre-1.0) where the API was different, or a corrupted installation.

fix

Upgrade to the latest version: 'pip install --upgrade pysoem'. Check import path: from pysoem import Master.

pysoem.slaves[0].sdo_read(0x1000, 1) -> OSError: SDO read failed

Network issues, slave not responding, or incorrect SDO index/subindex.

fix

Verify network connection and slave state. Ensure master.state is 'OP'. Check that the slave supports the SDO.

Upgrade

Version history

1.1.13latest on PyPI · released Jan 11, 2026

Audit

Dependencies

CythonoptionalRequired at build time if installing from source; pre-built wheels available for most platforms.

Agent activity

6 hits · last 30 days

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Resources

githubhttps://github.com/bnjmnp/pysoem ↗

packagehttps://pypi.org/project/pysoem/ ↗

docshttps://pysoem.readthedocs.io ↗