Users benefit from the changeover from PROFIBUS to PROFINET

“Is this new technology already perfected for real-world use? Are there really benefits? How long will it take to change over?”

Such are the questions that many companies might now be deliberating. All the more amazing then is the growth of PROFINET in recent years.

In 2012 alone, it grew by 35% and 2013 again over 30%. This growth is much more dynamic than that of PROFIBUS when it was introduced on the market.

In particular, PROFINET has experienced much stronger growth when compared with the general Industrial Ethernet market. Experts estimate that in just a few years there will be more new PROFINET nodes than PROFIBUS nodes.

One reason for this success can be attributed to the fact that the technical requirements for migration or introduction to the PROFINET world are not overly demanding.

There are also numerous ways to optimize costs. Moreover, many are using PROFINET in order to benefit from PROFIsafe or PROFIenergy.

Gradually or all at once?

Existing systems based on PROFIBUS DP can be easily ported to the new standard either gradually in logical, reasonable steps or all at once.

With a step-by-step strategy, it is also possible to give optimal consideration to operational requirements (changeover during lower production times, several machines/lines in succession, etc.).

In the simplest case, a higher-level PROFINET IO controller is installed in place of the previous controller, the head modules of the distributed I/O are replaced in the field, and the system components are networked together by PROFINET (aka Ethernet) cable.

What will be different after migration?

The key difference between PROFIBUS and PROFINET is most assuredly the network concept.

Users now have many different options for designing their automation landscape, perhaps by introducing new network structures, using PROFIenergy, or integrating wireless applications.

Of course, this new freedom should be exercised carefully. For large networks in particular, detailed network planning will provide for a stable, high-performance network.

A PROFIBUS application in machine construction typically has 50 to 100 devices. Thus, PROFIBUS users generally operate in a manageable world.

In PROFINET networks, this can look completely different. For example, networks with 10.000 and more nodes already exist in the automotive industry today.

But, it’s not just the number but also that type of networks that is completely different. There are different network structures and dynamic changes to the network possible, for instance in robots with frequent tool changeover. The networks are oriented vertically as well as horizontally and don’t always have to be purely used by PROFINET but allow other traffic as well.

More performance for the future

What are the benefits to users from migration to PROFINET?

This can be divided into three categories: flexibility, efficiency, and performance.

A key benefit of PROFINET is its significantly higher performance, especially with regard to node count, transmission speed, and diagnostics. Up to 256 nodes on one controller are already possible today. The size of networks is virtually unlimited. And the speed at 100 Mbps and full duplex mode of PROFINET is faster than that of PROFIBUS at 12 Mbps in the best case by an order of magnitude.

The two real-time transmission modes of PROFINET – RT (Realtime) and IRT (Isochronous Realtime) with clock synchronization – enable highly dynamic applications with deterministic cycle times.

Exploiting the benefits

As a general recommendation, for each pending automation project the individual requirements should be compared with the many different possible PROFINET solutions before making a decision.

In most cases, the advantages will outweigh any disadvantages – even for projects with a limited scope. For example, the investment costs are amortized faster over the service life of a PROFINET installation due to the shorter commissioning time and the higher availability, productivity, and quality of production.

Energy savings that can be achieved during production pauses with PROFIenergy also contribute to this. With continued growth of device counts and (as with PROFIBUS) broader dissemination of additional functionalities, the Total Cost of Ownership (TCO) of PROFINET systems will decrease even more.

Profibus Australia and the PICC (Pentair) offers comprehensive support for migration including from phone and onsite technical assistance..

Like for PROFIBUS for which installation instructions for easy commissioning have been available for years, the working groups at Profibus International have already created comparable documents for the use of PROFINET. However, these no longer cover just the installation by itself, such as branches, connectors, and the like. Rather, additional aspects such as layout variants and security measures are also emphasized.

In the end, this is one of the greatest strengths of PROFINET: Behind the technology stands a large community whose common goal is efficient production.

This article was prepared by Karsten Schneider (PI Chairman)

Minute PROFINET: PROFIsafe & PROFINET - Without having to run separate wires for safety relays, Functional Safety can be achieved using your pre-existing automation network. View Video here