pyModbusTCP

A simple Modbus/TCP client library for Python. pyModbusTCP is pure Python code without any extension or external module dependency.

Since version 0.1.0, a server is also available.

Tests

The module is currently test on Python 3.10, 3.11, 3.12, 3.13 and 3.14.

For Linux, Mac OS and Windows.

Documentation

Documentation of the last release is available online at https://pymodbustcp.readthedocs.io/.

Setup

You can install this package from:

PyPI, the easy way:

# install the last available release (stable)
sudo pip install pyModbusTCP

# install a specific version (here release v0.1.10)
sudo pip install pyModbusTCP==v0.1.10

From GitHub:

# install a specific version (here release v0.1.10) directly from github servers
sudo pip install git+https://github.com/sourceperl/pyModbusTCP.git@v0.1.10

Note on the use of versions:

Over time, some things can change. So, it’s a good practice that you always use a specific version of a package for your project, instead of just relying on the default behavior. Without precision, the installation tools will always install the latest version available for a package, this may have some drawbacks. For example, in pyModbusTCP, the TCP automatic open mode will be active by default from version 0.2.0. It is not the case with previous versions and it just doesn’t exist before the 0.0.12. This can lead to some strange behaviour of your application if you are not aware of the change. Look at CHANGES for details on versions available.

Usage example

See examples/ for full scripts.

include (for all samples)

from pyModbusTCP.client import ModbusClient

module init (TCP always open)

# TCP auto connect on first modbus request
c = ModbusClient(host="localhost", port=502, unit_id=1, auto_open=True)

module init (TCP open/close for each request)

# TCP auto connect on modbus request, close after it
c = ModbusClient(host="127.0.0.1", auto_open=True, auto_close=True)

Read 2x 16 bits registers at modbus address 0 :

regs = c.read_holding_registers(0, 2)

if regs:
    print(regs)
else:
    print("read error")

Write value 44 and 55 to registers at modbus address 10 :

if c.write_multiple_registers(10, [44,55]):
    print("write ok")
else:
    print("write error")

Release files for pyModbusTCP 0.3.1

For a detailed explanation of source distributions (sdists) and built distributions (wheels), please see the package formats documentation.

Source distribution (sdist)

Source distribution for pyModbusTCP 0.3.1
File	Size	Uploaded
pymodbustcp-0.3.1.tar.gz	32.1 kB	Sep 30, 2026	Details

Built distribution (wheel)

Table of built distributions (wheels) for pyModbusTCP 0.3.1
File	Interpreter	ABI	Platform	Reset
pymodbustcp-0.3.1-py3-none-any.whl 25.0 kB Sep 30, 2026	Python 3	none	any	Details

Total release size: 57.1 kB

Release files / pymodbustcp-0.3.1.tar.gz

Download URL	pymodbustcp-0.3.1.tar.gz
Size	32.1 kB
Tags	Source
SHA-256 checksum How to use checksums	`577ac1cf0ec4b629938606983f0fe97b16748759e5c939a8099c8a659a589a53`
BLAKE2b-256 checksum How to use checksums	`ad1b6945817cd0ad69b3b63583c3074b46ba3fa679cd14b35e2d98f5f85afe5f`
Upload date	Sep 30, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.13.5`

Release files / pymodbustcp-0.3.1-py3-none-any.whl

Download URL	pymodbustcp-0.3.1-py3-none-any.whl
Size	25.0 kB
Tags	Python 3
SHA-256 checksum How to use checksums	`f7679bd3daf8e0642a204c68efa233e180a26f0be8460049e32b19a4aee05cb0`
BLAKE2b-256 checksum How to use checksums	`02c8c71fdd48eadc4bbe62ac4fa69cb908b4c42ac8099bdef507b21392eb7241`
Upload date	Sep 30, 2026
Uploaded using Trusted Publishing? What is trusted publishing?	No
Uploaded via	`twine/7.0.0 CPython/3.13.5`