modbus-proxy 0.1.0

ModBus TCP proxy

ModBus TCP proxy

Many modbus devices support only one or very few clients. This proxy acts as a bridge between the client and the modbus device. This allows multiple clients to communicate with the same modbus device.

When multiple clients are connected, cross messages are avoided by serializing communication on a first come first served REQ/REP basis.

Installation

From within your favorite python environment type:

$ pip install modbus-proxy

Running the server

$ modbus-proxy -b tcp://0:9000 --modbus tcp://plc1.acme.org:502

Now, instead of connecting your client(s) to plc1.acme.org:502 you just need to tell them to connect to *machine*:9000 (where machine is the host where modbus-proxy is running).

Running the examples

To run the examples you will need to have umodbus installed (do it with pip install umodbus).

Start the simple_tcp_server.py (this will simulate an actual modbus hardware):

$ python examples/simple_tcp_server.py -b :5020

You can run the example client just to be sure direct communication works:

$ python examples/simple_tcp_client.py -a 0:5020
holding registers: [1, 2, 3, 4]

Now for the real test:

Start a modbus-proxy bridge server with:

$ modbus-proxy -b tcp://:9000 --modbus tcp://:5020

Finally run a the example client but now address the proxy instead of the server (notice we are now using port 9000 and not *5020):

$ python examples/simple_tcp_client.py -a 0:9000
holding registers: [1, 2, 3, 4]

Credits

Development Lead

• Tiago Coutinho [e-mail]

Contributors

None yet. Why not be the first?

History

0.1.0 (2020-11-11)

• First release on PyPI.