There’s Ethernet… and then there’s the industrial Ethernet.
One big difference is the distinction between soft and hard deadlines for delivery of information. An ordinary Ethernet connection treats a delivery failure as a total failure. It tried to deliver the information, the information was not delivered, so let’s all move on with our lives.
Or not. A hard deadline — there’s either success or failure — makes sense for flight control or other situations where a failure could literally be a life or death matter.
A soft deadline, when referring to an Ethernet connection, allows adjustment of deadlines, or some level of failure.
As Rexroth’s Matteo Dariol explains, “A hard real-time system considers missing a deadline to be a total failure. A soft real-time system, on the other hand, accepts missing some deadlines even if it degrades the output quality.” When the program compiles, it calculates the available resources and plans the best way to deliver the information and perform the operations.
This makes sense in an industrial setting.
Industrial Ethernet options are becoming increasingly important as the Industrial Internet of Things moves from an idea to a reality. There are, however, many different protocols.
Open source or not
Open source protocols are designed to work with different manufacturers and different kinds of machinery. Proprietary systems are intended to work only with a single kind of software or hardware.
The argument in favor of open source is that it allows faster progress, makes it possible for multiple machine builders to produce machines with greater connectivity, and encourages collaboration.
Opponents of open source say that it frustrates quality control and creates security vulnerabilities.
Until the two sides get closer together, there will be both open and not open (sometimes called “standard”) software for Ethernet protocols.
Did someone say “standard”?
There’s not much that’s standard about industrial Ethernet. Topology, costs, and ability to withstand extreme environments all vary significantly from one protocol to another.
The lack of standards may be an issue, especially as manufactures want and need to connect more different kinds of devices. However, industrial Ethernet is not just about software.
Devices used for connectivity in an industrial setting have to be able to handle temperatures, levels of vibration, and noise that don’t come up in office environments.
Fortunately, companies such as Rexroth are working together to create standards for the future.
In the meantime, count on us when you have issues of any kind with your Rexroth electric motion control.