FYI: Multi-read optimization integrated into upstream python-snap7

.github/workflows/test.yml

@@ -33,9 +33,10 @@ jobs:
           uv pip install ".[test]"
       - name: Run pytest
         run: uv run pytest --cov=snap7 --cov-report=xml --cov-report=term
-      - name: Upload coverage report
+      - name: Upload coverage to Codecov
         if: matrix.python-version == '3.13' && matrix.runs-on == 'ubuntu-24.04'
-        uses: actions/upload-artifact@v7
+        uses: codecov/codecov-action@v5
         with:
-          name: coverage-report
-          path: coverage.xml
+          files: coverage.xml
+          token: ${{ secrets.CODECOV_TOKEN }}
+          fail_ci_if_error: false

CHANGES.md

@@ -5,21 +5,43 @@ CHANGES
 -----
 
 Major release: python-snap7 is now a pure Python S7 communication library.
+This version completely breaks with the previous approach of wrapping the C snap7
+shared library. The entire S7 protocol stack is now implemented in pure Python,
+greatly improving portability and making it easier to install and extend.
 
 * **Breaking**: The C snap7 library is no longer required or used
 * Complete rewrite of the S7 protocol stack in pure Python
 * Native Python implementation of TPKT (RFC 1006) and COTP (ISO 8073) layers
 * Native S7 protocol PDU encoding/decoding
 * Pure Python server implementation for testing and simulation
-* No platform-specific binary dependencies
+* No platform-specific binary dependencies — works on any platform that runs Python
 * Improved error handling and connection management
 * Full type annotations with mypy strict mode
 * CLI interface for running an S7 server emulator (`pip install "python-snap7[cli]"`)
 
-If you experience issues with 3.0, pin to the last pre-3.0 release:
+If you experience issues with 3.0, please report them on the
+[issue tracker](https://github.com/gijzelaerr/python-snap7/issues) with a clear
+description and the version you are using. As a workaround, pin to the last
+pre-3.0 release:
 
     $ pip install "python-snap7<3"
 
+### Thanks
+
+Special thanks to the following people for testing, reporting issues, and providing
+feedback during the 3.0 development:
+
+* [@lupaulus](https://github.com/lupaulus) — extensive testing and bug reports
+* [@spreeker](https://github.com/spreeker) — testing and feedback
+* [@nikteliy](https://github.com/nikteliy) — review and feedback on the rewrite
+* [@amorelettronico](https://github.com/amorelettronico) — testing
+* [@razour08](https://github.com/razour08) — testing
+* [@core-engineering](https://github.com/core-engineering) — bug reports (#553)
+* [@AndreasScharf](https://github.com/AndreasScharf) — bug reports (#572)
+* [@Robatronic](https://github.com/Robatronic) — bug reports (#574)
+* [@hirotasoshu](https://github.com/hirotasoshu) — feedback (#545)
+* [@PoitrasJ](https://github.com/PoitrasJ) — bug reports (#479)
+
 1.2
 ---
 

README.rst

@@ -1,25 +1,63 @@
+.. image:: https://img.shields.io/pypi/v/python-snap7.svg
+   :target: https://pypi.org/project/python-snap7/
+
+.. image:: https://img.shields.io/pypi/pyversions/python-snap7.svg
+   :target: https://pypi.org/project/python-snap7/
+
+.. image:: https://img.shields.io/github/license/gijzelaerr/python-snap7.svg
+   :target: https://github.com/gijzelaerr/python-snap7/blob/master/LICENSE
+
+.. image:: https://github.com/gijzelaerr/python-snap7/actions/workflows/test.yml/badge.svg
+   :target: https://github.com/gijzelaerr/python-snap7/actions/workflows/test.yml
+
+.. image:: https://readthedocs.org/projects/python-snap7/badge/
+   :target: https://python-snap7.readthedocs.io/en/latest/
+
+.. image:: https://codecov.io/gh/gijzelaerr/python-snap7/branch/master/graph/badge.svg
+   :target: https://codecov.io/gh/gijzelaerr/python-snap7
+
 About
 =====
 
 Python-snap7 is a pure Python S7 communication library for interfacing with Siemens S7 PLCs.
 
+The name "python-snap7" is historical — the library originally started as a Python wrapper
+around the `Snap7 <http://snap7.sourceforge.net/>`_ C library. As of version 3.0, the C
+library is no longer used, but the name is kept for backwards compatibility.
+
 Python-snap7 is tested with Python 3.10+, on Windows, Linux and OS X.
 
 The full documentation is available on `Read The Docs <https://python-snap7.readthedocs.io/en/latest/>`_.
 
 
-Version 3.0 - Breaking Changes
-===============================
+Version 3.0 - Pure Python Rewrite
+==================================
+
+Version 3.0 is a ground-up rewrite of python-snap7. The library no longer wraps the
+C snap7 shared library — instead, the entire S7 protocol stack (TPKT, COTP, and S7)
+is now implemented in pure Python. This is a **breaking change** from all previous
+versions.
+
+**Why this matters:**
+
+* **Portability**: No more platform-specific shared libraries (`.dll`, `.so`, `.dylib`).
+  python-snap7 now works on any platform that runs Python — including ARM, Alpine Linux,
+  and other environments where the C library was difficult or impossible to install.
+* **Easier installation**: Just ``pip install python-snap7``. No native dependencies,
+  no compiler toolchains, no manual library setup.
+* **Easier to extend**: New features and protocol support can be added directly in Python.
 
-Version 3.0 is a major release that rewrites python-snap7 as a pure Python
-implementation. The C snap7 library is no longer required.
+**If you experience issues with 3.0:**
 
-This release may contain breaking changes. If you experience issues, you can
-pin to the last pre-3.0 release::
+1. Please report them on the `issue tracker <https://github.com/gijzelaerr/python-snap7/issues>`_
+   with a clear description of the problem and the version you are using
+   (``python -c "import snap7; print(snap7.__version__)"``).
+2. As a workaround, you can pin to the last pre-3.0 release::
 
-    $ pip install "python-snap7<3"
+       $ pip install "python-snap7<3"
 
-The latest stable pre-3.0 release is version 2.1.0.
+   The latest stable pre-3.0 release is version 2.1.0. Documentation for pre-3.0
+   versions is available at `Read The Docs <https://python-snap7.readthedocs.io/en/v2/>`_.
 
 
 Installation
@@ -29,4 +67,4 @@ Install using pip::
 
    $ pip install python-snap7
 
-No native libraries or platform-specific dependencies are required - python-snap7 is a pure Python package that works on all platforms.
+No native libraries or platform-specific dependencies are required — python-snap7 is a pure Python package that works on all platforms.

codecov.yml

@@ -0,0 +1,5 @@
+coverage:
+  status:
+    project:
+      default:
+        target: 80%

doc/API/async_client.rst

@@ -0,0 +1,49 @@
+AsyncClient
+===========
+
+.. warning::
+
+   The ``AsyncClient`` is **experimental**. The API may change in future
+   releases. If you encounter problems, please `open an issue
+   <https://github.com/gijzelaerr/python-snap7/issues>`_.
+
+The :class:`~snap7.async_client.AsyncClient` provides a native ``asyncio``
+interface for communicating with Siemens S7 PLCs.  It has feature parity with
+the synchronous :class:`~snap7.client.Client` and is safe for concurrent use
+via ``asyncio.gather()``.
+
+Quick start
+-----------
+
+.. code-block:: python
+
+   import asyncio
+   import snap7
+
+   async def main():
+       async with snap7.AsyncClient() as client:
+           await client.connect("192.168.1.10", 0, 1)
+           data = await client.db_read(1, 0, 4)
+           print(data)
+
+   asyncio.run(main())
+
+Concurrent reads
+----------------
+
+An internal ``asyncio.Lock`` serialises each send/receive cycle so that
+multiple coroutines can safely share a single connection:
+
+.. code-block:: python
+
+   results = await asyncio.gather(
+       client.db_read(1, 0, 4),
+       client.db_read(1, 10, 4),
+   )
+
+API reference
+-------------
+
+.. automodule:: snap7.async_client
+   :members:
+   :exclude-members: AsyncISOTCPConnection

doc/API/s7commplus.rst

@@ -0,0 +1,70 @@
+S7CommPlus (S7-1200/1500)
+=========================
+
+.. warning::
+
+   S7CommPlus support is **experimental**. The API may change in future
+   releases. If you encounter problems, please `open an issue
+   <https://github.com/gijzelaerr/python-snap7/issues>`_.
+
+The :mod:`snap7.s7commplus` package provides support for Siemens S7-1200 and
+S7-1500 PLCs, which use the S7CommPlus protocol instead of the classic S7
+protocol used by S7-300/400.
+
+Both synchronous and asynchronous clients are available. When a PLC does not
+support S7CommPlus data operations, the clients automatically fall back to the
+legacy S7 protocol transparently.
+
+Synchronous client
+------------------
+
+.. code-block:: python
+
+   from snap7.s7commplus.client import S7CommPlusClient
+
+   client = S7CommPlusClient()
+   client.connect("192.168.1.10")
+   data = client.db_read(1, 0, 4)
+   client.disconnect()
+
+Asynchronous client
+-------------------
+
+.. code-block:: python
+
+   import asyncio
+   from snap7.s7commplus.async_client import S7CommPlusAsyncClient
+
+   async def main():
+       client = S7CommPlusAsyncClient()
+       await client.connect("192.168.1.10")
+       data = await client.db_read(1, 0, 4)
+       await client.disconnect()
+
+   asyncio.run(main())
+
+Legacy fallback
+---------------
+
+If the PLC returns an error for S7CommPlus data operations (common with some
+firmware versions), the client automatically falls back to the classic S7
+protocol. You can check whether fallback is active:
+
+.. code-block:: python
+
+   client.connect("192.168.1.10")
+   if client.using_legacy_fallback:
+       print("Using legacy S7 protocol")
+
+API reference
+-------------
+
+.. automodule:: snap7.s7commplus.client
+   :members:
+
+.. automodule:: snap7.s7commplus.async_client
+   :members:
+
+.. automodule:: snap7.s7commplus.connection
+   :members:
+   :exclude-members: S7CommPlusConnection

doc/connecting.rst

@@ -0,0 +1,100 @@
+Connecting to PLCs
+==================
+
+This page shows how to connect to different Siemens PLC models using
+python-snap7.
+
+.. contents:: On this page
+   :local:
+   :depth: 2
+
+
+Rack/Slot Reference
+-------------------
+
+.. list-table::
+   :header-rows: 1
+   :widths: 20 10 10 60
+
+   * - PLC Model
+     - Rack
+     - Slot
+     - Notes
+   * - S7-300
+     - 0
+     - 2
+     -
+   * - S7-400
+     - 0
+     - 3
+     - May vary with multi-rack configurations
+   * - S7-1200
+     - 0
+     - 1
+     - PUT/GET access must be enabled in TIA Portal
+   * - S7-1500
+     - 0
+     - 1
+     - PUT/GET access must be enabled in TIA Portal
+   * - S7-200 / Logo
+     - --
+     - --
+     - Use ``set_connection_params`` with TSAP addressing
+
+.. warning::
+
+   S7-1200 and S7-1500 PLCs ship with PUT/GET communication disabled by
+   default. Enable it in TIA Portal under the CPU properties before
+   connecting. See :doc:`tia-portal-config` for step-by-step instructions.
+
+
+S7-300
+------
+
+.. code-block:: python
+
+   import snap7
+
+   client = snap7.Client()
+   client.connect("192.168.1.10", 0, 2)
+
+S7-400
+------
+
+.. code-block:: python
+
+   import snap7
+
+   client = snap7.Client()
+   client.connect("192.168.1.10", 0, 3)
+
+S7-1200 / S7-1500
+------------------
+
+.. code-block:: python
+
+   import snap7
+
+   client = snap7.Client()
+   client.connect("192.168.1.10", 0, 1)
+
+S7-200 / Logo (TSAP Connection)
+--------------------------------
+
+.. code-block:: python
+
+   import snap7
+
+   client = snap7.Client()
+   client.set_connection_params("192.168.1.10", 0x1000, 0x2000)
+   client.connect("192.168.1.10", 0, 0)
+
+Using a Non-Standard Port
+--------------------------
+
+.. code-block:: python
+
+   import snap7
+
+   client = snap7.Client()
+   client.connect("192.168.1.10", 0, 1, tcp_port=1102)