In order to understand the potential of this disruptive Ethernet technology, it is necessary to go backwards 50 years to see the different data links that have been established over time. In the 70s and 80s, proprietary hardware-oriented point-to-point links were established. For various markets, different bus protocols have been developed. There was no networking functionality, and in the late 90s to early 2000, the first packet-oriented links were developed. Ethernet was becoming a major technology in generic cabling and later also in industrial environments with protocols like Ethernet/IP or PROFINET. Ethernet gave the possibility of using different media such as copper, fiber, and Wi-Fi, and has become the major communication protocol for all types of applications. Today's younger engineers coming fresh from the university will have difficulties developing products for Fieldbus infrastructures that are nearly 30 to 40 years old. The logical way out of the so-called “Fieldbus Zoo” is using Ethernet technology. This will converge control networks to Ethernet-based networks. Single pair Ethernet seems to be the most promising candidate for this disruptive change in communication architecture. It provides full Ethernet transparency and functionality, including a 24 V / 60 W power supply called power over data line (PoDL).