The Engineering Projects

So I am storing data in a text file on my raspberry pi (B). The data is just a series of numbers from an analog read from a teensy. I want to have a Modbus connection with another raspberry pi (A) and have it call for the most recent analog data recorded. Any ideas on how I can do this or any points to in the right direction. I'm pretty new to Modbus so I don't know much. I am reading up on it but I don't know how to incorporate what I've learned into python.

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