Over the past two decades, industrial facilities have seen a significant number of fieldbus communication networks replaced by Industrial Ethernet. According to a 2021 study by HMS Networksindustrial Ethernet represents 65% of new nodes installed, while fieldbuses represent 28% of new nodes installed.
With the continued advance of Time-Sensitive Networking (TSN) through many new product offerings and its ability to bring determinism to standard Ethernet, some might wonder if it’s only a matter of time before that industrial Ethernet protocols like Profinet, CC-Link IE, EtherNet/IP and EtherCAT are starting to fall behind TSN. A closer look at TSN and Industrial Ethernet protocols explains why this is unlikely and impossible for the foreseeable future.
According to Thomas Burke, Global Strategic Advisor at CLPA (CC-Link Partner Association), “TSN technology only addresses network functions at layer 2 (data link) of the Open System Interconnection (OSI) model for communications. Therefore, it is only responsible for transmitting data from one place to another in a deterministic manner without looking at what the data is. What needs to be done with the data is usually managed at higher level layers that meet application requirements. These are managed by industrial Ethernet technologies.
Burke notes that some users may wonder why TSN and Industrial Ethernet are needed since most Industrial Ethernet protocols can provide determinism if needed. He says the answer lies in convergence.
“Generally, most industrial Ethernet protocols don’t allow merging different types of traffic on the same network,” Burke explains. “TSN adds this missing capability by allowing multiple types of traffic to share the same network while being treated deterministically.”
Burke advises OEMs and end users to explore the use of TSN-compatible industrial Ethernet protocols to ensure that these protocols can address the I/O, motion control, and security aspects of the intended application. For example, he notes that the CC-Link IE TSN protocol uses layers 3 through 7 of the OSI reference model to build on the capabilities of the layer 2 TSN. “In doing so, it allows I/O, motion, and security control to be integrated into standard TCP/IP traffic in a deterministic way.”