Let’s get real for a minute. When it comes to Ethernet IP – Rockwell comes to mind. When we hear Profinet – Siemens comes to mind. While they are not the only vendor that utilizes Profinet they are the heavyweight user. So, which one is better? Prepare for a Ford/Chevy type of debate if you bring this up.
Typically, regions follow protocols. For instance, in Europe Profinet is heavily installed while in the US Ethernet is the predominant protocol of use. Both have their advantages and together take up around 60% of market share worldwide so they are obviously doing things right. Digging into this topic there are a few areas to consider.
Determinism is when a data set, like a message or instruction, is sent from X and when Y should expect to receive it. Unfortunately, there isn’t 100% determinism in either protocol. As with other protocols where this is clearly defined and can be counted on there are gaps in both Ethernet and Profinet in this regard. So, if we were to line these heavyweights up in a ring what could we expect?
In the Blue Corner
The Profinet stat sheet in this fight would highlight their ability to jump protocol levels. They have a speed advantage because they can go directly into applications. So, from a fighting analogy standpoint, they are delivering a lot of punches very quickly. This could lead to a win in on fight night.
In the Red Corner
The Ethernet stat sheet in the fight would highlight their interoperability. Other components can utilize and process the information. Sticking with the fighting analogy, they would be landing targeted punches up and down their opponent. While they may not punch as fast, they would be more effective in the number of areas they hit and that could be big in overall success.
Ding Ding Ding let’s see how this goes!
Both have pros and cons. Profinet can say they are faster while ethernet uses common industrial protocol (CIP) which is increasing time sync capabilities. It really comes down to preference on the installed base of equipment to understand the pros and cons of each. Both should yield reliable results when configured correctly. It’s worth noting that the protocols can convert to each other if needed. Both can operate on the same medium which reduces some hurdles also.
Resources for further education are ODVA (selection guides, white papers) for Ethernet/IP and Profinet PI organization which has multiple resources to review and assist in design.