Industry 4.0 - network capacity

Hello fellow members,

here at VDAB we're investigating the needs for training towards Industry 4.0. I'm currently looking into what setting we may buy to train people on the skills needed for that hype. One of the things that nobody seem to be able to answer, at least not the commercial guys who want us to buy their stuff, is what network capacity is needed. I know it is depending on the number of intelligent sensors and the frequency of the data exchange, but isn't there a simple rule of thumb that can help me convince the IT department of the needs we have?

Thanks everybody, I know the answer is among us! It's just a matter of time to get it here.

Personally, I can't see you needing anything more than 100 Mbit capable networking within a classroom environment. But why not get stuff with 10, 100, 1000 and get them to see what level of traffic each can handle?

What would be more important is having a range of networking gear so you can teach them why there is a difference between a cheap unmanaged "home office" switch and a industrial managed switch. Teach them about VLANs, teach them about ring redundancy, and for goodness sake teach them how layer 3 routing and subnetting works!

Being able to troubleshoot networking issues using wireshark is another valuable skill. I had to do that just this week when a slightly slow colleague couldn't figure why his remote IO was not getting assigned the address he was expecting. He'd just hooked up all this new gear and a new switch into an existing network. He spent half a day stumped. After 5 minutes with Wireshark i found another router assigning the address via DHCP instead of his PLC. VLAN'd off his PLC, problem solved.

I find that 100 meg Ethernet is fast enough for 99% of automation applications. The automation exceptions are either massive IO installs, or many axes of super fast motion control, and those can usually be solved with a 2nd interface. The other exception is streaming video, which is becoming more and more common. I've seen plenty of systems where an HMI/SCADA couldn't get enough bandwidth, but that was because the PLC couldn't process the requests fast enough, not because Ethernet was too slow.

I generally recommend a minimum of 1 gig Ethernet as the links between cells or uplinks to the plant, to future proof things, and then 100 Meg in each cell.

Even if you aren't going to buy gig switches, is still buy gig cables. Makes upgrading later much simpler.

jvdcande said:

here at VDAB we're investigating the needs for training towards Industry 4.0. I'm currently looking into what setting we may buy to train people on the skills needed for that hype.

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This sounds like a mandate from some unknowing bureaucrat.

Ditto, getting the 100 Mbs ethernet and managed switches. A lot of the Industry 4.0 involves networking to a cloud. This is more of an IT function and not a PLC programmer function.

There is nothing new really at the machine floor. 100Mps has been around for a long time and so has the need for managed switch to separate Ethernet traffic from the different machine centers and the office. Search back a long time on this forum for Tumbarumba, AU and the leaning curve to network the plant.

Right now our Ethernet programmer is upgrading our Profinet software. It is a moving target as the specifications get tighter, stringent and probably better. I know Siemens has some good test software that is allowing us to test our products more thoroughly. I don't know if that would help you with your requirements but since you are in Siemens land you might ask what is available for network testing. It won't be cheap.

BTW, I have heard rumblings that 100 Mps is not fast enough for some CIP motion applications. The problem is that the Ethernet processing may need to process 10 times as many packets per second.

Peter Nachtwey said:

BTW, I have heard rumblings that 100 Mps is not fast enough for some CIP motion applications. The problem is that the Ethernet processing may need to process 10 times as many packets per second.

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I suspect that could be why they went to the built in gig port on the L8s. I'm curious what the real bandwidth out of the interface is; sometimes "gig" just means "faster than 100mbps".

I think I've gotten near that limit in PN with motion, but from what I've seen the processor usually maxes out before we hit the 100 meg limit on the IO.

mk42 said:

I suspect that could be why they went to the built in gig port on the L8s. I'm curious what the real bandwidth out of the interface is; sometimes "gig" just means "faster than 100mbps".

I think I've gotten near that limit in PN with motion, but from what I've seen the processor usually maxes out before we hit the 100 meg limit on the IO.

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The Gbs peak speed is real but I doubt anyone would get a true Gbs because it takes time to process the data. No one gets 100Mbs on a 100Mbs Ethernet for the same reason.

What would be interesting is to compare 100Mbs Ethercat with 100Mbs Profinet or CIP motion. However, I don't think this is what is wanted to satisfy the Industry 4.0 hype.

Peter Nachtwey said:

What would be interesting is to compare 100Mbs Ethercat with 100Mbs Profinet or CIP motion. However, I don't think this is what is wanted to satisfy the Industry 4.0 hype.

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I know the Ethercat guys put out a white paper years ago with charts saying Ethercat was fastest, least overhead, etc. I'm not sure how much of it was fair comparisons, though, and I know the PN guys came out with some updates in the past couple years to even things up. I'm not sure on the capabilities of CIP motion. From what I know of Ethercat, it is kind of a one trick pony: capable of high speeds for motion, but the IT guys cry when they see nonstandard Ethernet.

You are right, though, definitely a siding on the the 4.0 hype train.

Well, as was mentioned, it had to do with bureaucracy, but not for the reasons mentioned.

At VDAB, we're not sitting in classrooms, but in a sort of simulated work environment. The drives and the PLCs are setup such as it resembles a factory environment.

At the moment we're already experiencing problems with our WiFi setup and we want the IT department to look in to it. But they want us to say what the real needs are before they even think about moving a finger. So I've been given the task to gather info and as always, I've turned to the best place I know to start with.

Could the issue be saturation of wifi with lots of users in close proximity?

WiFi is bad for this. Unreliable and suffers from congestion just when lots of WiFi nodes are near. They don't even need to be connected to said AP.

This 4.0 hype is being approached the wrong way. Being bombarded with promises of what is possible. Well yeah, flying cars are also possible, doesn't mean they're viable. Doesn't mention we're gonna need to know so much more than just your basic driving skill to properly use said flying car.

If you're gonna teach 4.0, start with basic networking. Or rather networking basics. Along with cybersecurity. Few things annoy me more than being able to approach an engineering station from the internet. Teach proper segregation techniques. How to keep your lower level IO's separate from your MES servers.

In a properly set up 4.0 environment you don't need anything more than 100mb between devices and layers. It would be advisable to have 1gb as backbone network, especially for the higher level systems such as MES, historians, scada, gateway between your industrial network and the cloudbased 4.0 services, etc.

Jeebs,

I do know we'll need networking basics (already covered in our trainings) and network security (I have been striking that nail for the last 20 years or so).

Industry 4.0 being nothing more than a hype is also notthing new to me, but as you know management is getting a you-know-what when they even just hear the term.

I'm convinced we're better of with laptops with two hardwired ethernetports, but IT keps saying we already have two: one ethernet port and one WiFi connection. You know, it's the old struggle between IT, knowing almost nothing about industrial IT, and us, where IT considers us as IT dummies.

Nevertheless, thanks for your point of view. I'll try to get USB to Ethernet converters for my guys and we'll hope for the best.

BTW For everybody reading this thread: in my opinion, Industry 4.0 has been here for the last 30 or so years. In the automotive industry batch sizes of 1 are being used as long as that, big data has been gathered there about as long as that as well, only the connection of machine level components to the internet is fairly new. New is also that this technology comes within reach for even the small and medium companies.