PyModbus Documentation

1 PyModbusRelease Source volunteersJul 01, 2023 CONTENTS:1 PyModbus - A Python Modbus Supported versions .. Summary .. Features .. Client Features .. Server Features .. Use Cases .. Example Code .. Examples Directory structure .. PyModbus REPL (Read Evaluate Print Loop) .. PyModbus REPL Client .. PyModbus REPL Server .. Installing .. Current Work In Progress .. Development Instructions .. Generate Documentation .. Contributing .. License Information .. 62 version .. version .. version .. version (picked from dev, only bugfixes) .. version (picked from dev, only bugfixes) .. version .. version .. version .. version.

2 Version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. Version .. 243 Transport classes .. Modbus calls .. 344 Server435 Configuration .. Json file layout .. Server entries .. Server configuration examples.

3 Device entries .. Setup section .. Invalid section .. Write section .. Bits section .. Uint16 section .. Uint32 section .. Float32 section .. String section .. Repeat section .. Device configuration examples .. Configuration used for test .. Simulator datastore .. Web frontend .. PyModbus simulator ReST API .. 69ii6 Dependencies .. Usage Instructions .. DEMO .. REPL client classes .. REPL server classes .. 877 Datastore classes .. 918 module .. module .. module .. module .. 1039 Constants10710 Extra functions11111 Ready to run examples: .. Simple asynchronous client .. Simple synchronous client .. Advanced examples.

4 Asynchronous client .. Asynchronous client basic calls .. Asynchronous server .. Build bcd Payload .. Callback Server example .. Custom Message client .. Message generator .. Message Parser .. Modbus forwarder .. Modbus payload client .. Modbus payload Server .. Synchronous client .. Synchronous server .. Updating server .. Examples contributions .. Redis datastore .. Serial Forwarder .. Sqlalchemy datastore .. 21912 Indices and tables223 Python Module Index225 Index227iiiivCHAPTERONEPYMODBUS - A PYTHON MODBUS STACKWe are constantly working the modernize PyModbus and add new features, and we look for people who want to help abit. There are challenges small and large not only programming but also Documentation and Supported versionsVersion is the last release (python >= , no longer supported).

5 Version is the current release (Tested with Python >= ).Important:All API changes after are documented in SummaryPymodbus is a full Modbus protocol implementation using a synchronous or asynchronous (using asyncio) modbus protocol Documentation can be found hereSupported modbus communication modes: tcp, rtu-over-tcp, udp, serial, tlsPymodbus can be used without any third party dependencies (aside from pyserial) and is a very lightweight also provides a lot of ready to use examples as well as a server/client simulator which can be controlled viaa REST API and can be easily integrated into test Python >= tests are run against Python , , , on Windows, Linux and , Release Client Features Full read/write protocol on discrete and register Most of the extended protocol (diagnostic/file/pipe/setting/informatio n) TCP, RTU-OVER-TCP, UDP, TLS, Serial ASCII, Serial RTU, and Serial Binary asynchronous(powered by asyncio)

6 And synchronous versions Payload builder/decoder utilities PyModbus REPL for quick tests Customizable framer to allow for custom Server Features Can function as a fully implemented modbus server TCP, RTU-OVER-TCP, UDP, TLS, Serial ASCII, Serial RTU, and Serial Binary asynchronous and synchronous versions Full server control context (device information, counters, etc) A number of backend contexts as Use CasesAlthough most system administrators will find little need for a Modbus server on any modern hardware, they may findthe need to query devices on their network for status (PDU, PDR, UPS, etc). Since the library is written in python, itallows for easy scripting and/or integration into their existing , most monitoring software needs to be stress tested against hundreds or even thousands of devices (whythis was originally written), but getting access to that many is unwieldy at PyModbus server will allow a user to test as many devices as their base operating system will allow (allowin thiscase means how many Virtual IP addresses are allowed).

7 For more information please browse the project Documentation : Example CodeFor those of you that just want to get started fast, here you go:from importModbusTcpClientclient = ModbusTcpClient(' ') () (1,True)result = (1,1)(continues on next page)2 Chapter 1. PyModbus - A Python Modbus StackPyModbus, Release (continued from previous page)print( [0]) ()For more advanced examples, check out the Examples included in the repository. If you have created any utilities thatmeet a specific need, feel free to submit them so others can Examples Directory structureexamples-> Essential examples guaranteed to work (tested with our CI) -> Examples not updated to version -> Examples contributed by , if you have a question, please create a post in discussions q&a topic, so that others can benefit from the you think, that something in the code is broken/not running well, please open an issue, read the Template-text firstand then post your issue with your setup PyModbus REPL (Read Evaluate Print Loop)

8 WarningThe PyModbus REPL Documentation is not PyModbus REPL ClientPymodbus REPL comes with many handy features such as payload decoder to directly retrieve the values in desiredformat and supports all the diagnostic function codes directly .For more info on REPL Client refer PyModbus REPL PyModbus REPL (Read Evaluate Print Loop)3 PyModbus , Release PyModbus REPL ServerPymodbus also comes with a REPL server to quickly run an asynchronous server with additional capabilities out of thebox like simulating errors, delay, mangled messages more info on REPL Server refer PyModbus REPL InstallingYou can install using pip or easy install by issuing the following commands in a terminal window (make sure you havecorrect permissions or a virtualenv currently running):pip install -U pymodbusThis will install a base version of install PyModbus with options run:pip install -U PyModbus [<option>.]

9 ]Available options are: repl, installs PyModbus REPL. serial, installs serial drivers. Documentation , installs tools to generate Documentation . development, installs development tools needed to enable test/check of PyModbus to install a specific release:pip install -U PyModbus == you can pull the trunk source and install from there:4 Chapter 1. PyModbus - A Python Modbus StackPyModbus, Release clone pymodbuspip install -r cloning the repo, you need to install python3 (preferable ) and make a virtual environment:python3 -m venv /path/to/new/virtual/environmentTo activeate the virtual environment please do:source .venv/bin/activateTo get latest release (for now with Python support):git checkout masterTo get bleeding edge:git checkout devTo get a specific version:git checkout -b :pip install -r install -e.

10 Pre-commit installThis installs PyModbus in your virtual environment with pointers directly to the PyModbus directory, so any changeyou make is immediately available as if installed. It will also installpre-commitgit method will install all the required dependencies (at their appropriate versions) for your current python repository contains a number of important branches and tags. devis where all development happens, this branch is not always stable. masteris where are releases are kept. All releases are tagged ( ) All prereleases are tagged ( )If a maintenance release of an old version is needed ( ), the release tag is used to create a branch with thesame name, and maintenance development is merged Installing5 PyModbus , Release Current Work In ProgressThe maintenance team is very small with limited capacity and few modbus , if you would like your device tested, we accept devices via mail or by IP said, the current work mainly involves polishing the library and solving issues.