I have a proof of concept project in mind for a potential client within the brewery industry.
Fist here's a simple context diagram of what I'd like to achieve:
Image link: https://pasteboard.co/GDoCYPq.png
The client has two air compressors running to supply compressed air for manufacturing PET-bottles. Once created/blown up, they are cleaned (more air used), filled (water, soda,beer), packed and shipped. In summary, it's pretty important that these machines are running 24/7. Each machine is controlled by a PLC, that ensures the physical they run correctly by reading inputs (temp, pressure) and monitoring these values against treashold values that must not be breached or the PLC shuts down the machine.
Read out the PLC process data over modbus every Xs and send it to a remote micro service (mqtt/Jason). Display the data on a dashboard in near real-time for remote readout. Monitor data against the same treasholds, alert the operations of a potential failure before the machine is shut down.
I am confident on the software side of things, hardware/modbus not so much...
To my eyes the unipi looks like it can fulfill all of the above, am I wrong?
Would I need a unipi per PLC or can I read more than one with a the single rs485/modbus connection?
Can I read the data of the PLC using nodered (nodered supports modbus) or will I need something more?