MinimalModbus is an easy-to-use Python module for talking to instruments (slaves) from a computer (master) using the Modbus protocol, and is intended to be running on the master. Example code includes drivers for Eurotherm and Omega process controllers. The only dependence is the pySerial module (also pure Python).
This software supports the ‘Modbus RTU’ and ‘Modbus ASCII’ serial communication versions of the protocol, and is intended for use on Linux, OS X and Windows platforms. It is open source, and has the Apache License, Version 2.0. Tested with Python2.7 and Python3.2.
Very useful module! Thank you!