Tips and Tricks from the PROFINET 2008 Training Events

Carl Henning, deputy director of PTO North America, blogs about PROFIBUS and PROFINET developments in his popular PROFIblog. Here are excerpted highlights taken from recent postings on the 2008 training events.

Aw 3327 0812profi Carl Headshot

Our one-day training classes have concluded for 2008 and we are already planning for 2009. Watch the website to see next year’s schedule. But let’s finish 2008 first.

I was in Chicago (Oak Brook, actually) for the final PROFINET one-day training event of 2008 as I blogged last time. Now let me respond to some of the topics brought up in the course evaluations.

One attendee wanted to know more about “How to access standard Ethernet products over a PROFINET network.” The answer: Pretend PROFINET is not there; PROFINET is just Ethernet so it does not impact standard Ethernet devices. The beauty of Ethernet is that it supports multiple applications at the same time. Just use your standard Ethernet devices like you would in any non-PROFINET network. Two caveats.  One, if you are using PROFINET for motion control, be sure you enter the motion control portion of the network through a PROFINET IRT-capable Ethernet switch. Two, if your other application is Ethernet/IP, make sure you have IGMP snooping in the managed switches to keep EIP from flooding the network.

Here’s a few more items attendees at our one-day training events asked to be covered in greater detail:

 

  • Integration from PROFIBUS to PROFINET
  • Application examples—show us the code!
  • CBA configuration
  • PROFINET topologies

Integration from PROFIBUS to PROFINET  
Our coverage of this is fairly brief, but this integration is also very easy. Basically, you add a proxy between the networks. A proxy is like a gateway in that it interconnects two diverse networks, but unlike a gateway it is part of the PROFINET specification. A gateway is typically the product of a single vendor who happens to know both networks. With a proxy the mapping between the two networks is fixed in the specification. For example, when we specified the HART proxy we invited the HART Communication Foundation to participate in the Working Group.

Application examples
We do try to show some of the code, but time really limits us. For more detail (and more code) I recommend the week-long PROFINET Certified Network Engineer class. We don’t have any available for the remainder of this year, but watch the website for next year’s schedule.

CBA
Component Based Automation (CBA) is the name for our peer-to-peer networking technique. It allows horizontal integration without programming. A simple GUI allows graphical configuration instead.

PROFINET topologies
PROFINET allows star, tree, (virtual) line, and ring topologies. I qualify line as “virtual” because it is not a bus topology like PROFIBUS, just a virtual bus. With PROFIBUS the wiring passes unbroken through connectors that attach to the devices; with PROFINET, the wiring goes into and out of an Ethernet switch. It just happens that the switch is built into the device.  This gives us the best of both worlds—Ethernet and a linear topology. A topology discussion would not be complete without…

Security
In addition to the topology considerations within the automation environment, the interconnection to the office and beyond must be considered. While we cover this in the class, the details are in our long-published “Security Guideline.”  It’s available online by clicking here.

Differences between various Ethernet bus systems
We do offer a competitive comparison chart for each area—IO, CBA, motion control, etc. Our past experience has been that if we dwell on this too much we are accused of being overly critical of the competition. So we present this as succinctly and factually as we can.  We also hand out the booklet, “PROFINET or the story of Pretty Polly, Sweet Sue, and the White Knight” which goes into additional detail. You can order your own downloadable or hard copy edition on the booklet from our website here.


For more on Carl Henning’s PROFIblog, visit www.profiblog.com.

More in Control