What is the difference between PROFIBUS and PROFINET?

The fundamental difference between PROFIBUS and PROFINET is that PROFIBUS is a classic serial Fieldbus, while PROFINET is an industrial Ethernet protocol. Because of their common source, the PI organization, they share some similarities but overall they are different.

The major representation/visual difference is that PROFINET uses the green industrially graded Ethernet cables, with the most common connector type of RJ45, or sometimes M12 connectors in high exposure environments and BFOCs fiber optic installations. PROFIBUS networks on the other side, are characterized by a purple single-pair RS-485 cabling, using the standard DB9 or M12 connectors.

PROFIBUS networks can achieve speeds of up to 12 Mbit/s, but they generally run at 1.5 Mbit/s. The data size (telegram_ can be up to 244 bytes, with address space limited to 126 devices per network.

PROFINET networks on the other hand can achieve speeds of 100 Mbit/s, (sometimes even up to 1 Gbit/s), with telegram size up to 1440 bytes and virtually no address limiting space.

Another crucial difference is the data exchange mechanism, where PROFIBUS employs master-slave interaction, while PROFINET uses the consumer provider model.

PROFINET takes advantage because of the use of future-proof Ethernet technology, providing higher bandwidth, bigger message sizes, and unlimited address space. One more possible advantage is the PROFINET has gone one step further when it comes to defining proxies - gateways that can translate their network to another one.