What is this?

This project was created as a way for me to refresh my knowledge on python, as well as to showcase the things I've learned about how SCADAs work thus far.

The "Architecture"

This project is made up of 3 main components:

• The Flask app
• The Modbus server
• The MQTT listening process

The Flask App

This is the bulk of the functionality. It contains a REST API that mainly stores Device/Tag associations, as well as their respective configurations for things like a Device's network configuration or the different communication protocol configurations associated with a Tag.

The Flask app runs on the default port of 5000.

The Modbus server

This is a very simple modbus server, mainly meant to serve a simple store of values that are read/written to via Modbus. It runs on localhost:8502

The MQTT listening process

This process is responsible for subscribing to each Device's MQTT topic, and parsing/handling the message. Each message is assumed to be JSON, and all invalid JSON will be ignored. It checks the keys on the JSON object and against a matching Tag's MQTT configuration and performs a Modbus write on the Tag's Modbus configuration.

How do I start this thing?

Flask App

Make sure you have a SQLite database initialized:

touch ./flask_app/instance/db.sqlite

Copy the example .env file and fill it out:

cp ./flask_app/.env.example ./flask_app/.env

Run the migrations:

cd ./flask_app/ && alembic upgrade head

Start it by running:

source venv/bin/activate && cd flask_app && flask run

Modbus App

To start the Modbus app:

source venv/bin/activate && cd modbus_server && python3 ./server.py 

MQTT Listener App

Make sure that you have Mosquitto installed on your local machine, here is the command for linux:

sudo apt-get install mosquitto

Copy the example .env file and fill it out:

cp ./mqtt_server/.env.example ./mqtt_server/.env

To start the MQTT app:

source venv/bin/activate && cd mqtt_server && python3 ./app.py