I have an Unitronics V570 PLC which takes temperature readings. An Ethernet card enabled PLC is really expensive so I plan to connect the PLC to a Raspeberry PI. How can I use Python functions that allow the computer to connect to web pages. I will eventually build a web site with PHP that will accept a connection from the Raspberry Pi. I will then let the web page load the data into a MySQL database and operators can view this data online.
My question is: How can I connect the raspberry Pi to the PLC to extract all the data I would need to send to the web page. The Rpi has a serial port built into its GPIO connector and I have built an interface that would allow serial connection between the Rpi and the PLC. How can I establish connections between the Rpi and the PLC? I will be using RS232 communications from the PLC to Rpi