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 for test purpose only (don't use in project).
The module is currently test on Python 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12.
For Linux, Mac OS and Windows.
Documentation of the last release is available online at https://pymodbustcp.readthedocs.io/.
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/[email protected]
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.
See examples/ for full scripts.
from pyModbusTCP.client import ModbusClient
# TCP auto connect on first modbus request
c = ModbusClient(host="localhost", port=502, unit_id=1, auto_open=True)
# TCP auto connect on modbus request, close after it
c = ModbusClient(host="127.0.0.1", auto_open=True, auto_close=True)
regs = c.read_holding_registers(0, 2)
if regs:
print(regs)
else:
print("read error")
if c.write_multiple_registers(10, [44,55]):
print("write ok")
else:
print("write error")