Pymodbus is a full Modbus protocol implementation. It is currently supports the following :

Client Features:
* Can perform single get/set on discrete and registers
* Can perform multiple get/set on discrete and registers
* Working on diagnostic/file/pipe/setting/info requests
* Can fully scrape a host to be cloned
Server Features:
* Can function as a fully implemented TCP/ASCII modbus server
* Full server control context
* Working on serial communication
* Working on functioning as a RTU
* Can mimic a server based on the supplied input data
For asynchronous communication, you need python-twisted-core. For serial communication, you need python-serial.

This package provides the Python 2.x module.