An oft-heard question: “Why does a PROFINET device need an IP address? PROFINET uses names.” You may have heard the misinformation that PROFINET does not use TCP/IP. The correct information is that PROFINET does use TCP/IP and devices do have IP addresses!
So, the short answer to that oft-heard question: PROFINET uses TCP/IP and therefore needs an IP address.
The long answer is pretty simple: PROFINET uses TCP/IP where it makes sense (that is, where the data is not time-critical). For example:
Therefore, an IP address is needed for these functions. There are also other benefits. Many devices have embedded Web servers. This allows you to type in their IP address into a Web real-time browser and access them like a webpage. One of the biggest reasons people are moving to PROFINET is data access. By using IP addresses, it helps integrate device-level information vertically into higher-level MES systems.
Now, PROFINET does not use the IP address for real-time data; it just uses the physical address, the MAC address. This means it can skip TCP/IP for faster, more deterministic performance.