Thank you for your reply, Saragani-san!
They are simple valve opening and closing commands, flow meter pulse monitoring. Besides reading the RFID card (13.56 MHz), which has the TAG recognition, it is sent to the web server and it will return with the valve and meter commands.
I say independent because they are more stations controlled by a PLC. Each station has a set of a reader, solenoid valve, meter and IP address. Where each client can access at any time and simultaneously.