Network configuration that could be used to connect a programmable controller system

[Etech1]

I will take a look at the sites you have suggested and see if I can find something there. Thankyou for your help.

 

[Maxkling]

So you can choose the protocol correct?

 

[rpoet]

I have been given the following question for part of my coursework,
a) Describe a communications network that could be used with a modern PLC system.
Guidance: Your work should include referenced evidence, and appropriate illustrations. The configuration type also needs to be supported with evidence that shows it is a real (commercial) network rather than one just in theory
The problem I am having is how can I show that a network is commercial? My original answer to this was basically as follows; line topology, rs485 communication standards with modbus protocol. I then referenced a company who use this exact configuration to connect their PLC controlled robot cells. However, the tutor says I have not linked my answer to a real commercial network. How else could I possibly show this is a "real" network and not just one in theory?
Thankyou in advance for your time

Photo of a PLC with an Ethernet port. Tech specs showing what protocols the PLC is capable of using. Link to Wikipedia page on Ethernet.

In all seriousness, your professor sounds like the Ivory Tower type that hasn't been out in the world and actually doing this for a long time (if ever). This is a terribly worded and constructed assignment. You can't swing a dead cat in a production environment without hitting a PLC with some type of COMs usage. What does he want, a picture of a control panel?

I'm happy to send you a photo of a control panel using Ethernet (with and without PoE), wired and wireless DMX, WiFi, and 4G LTE - all in the same enclosure. Does he want the schematics too? I'd attach it here, but the file size limitations of the forum make the photo look like it was taken with a potato.

As far as showing that a network is "commercial" I think Ethernet is a pretty easy case to make. It's installed in just about every building larger than a dog house these days. If he doesn't accept Ethernet without "commercial evidence" he's being a pedantic a$$.


-rpoet

 

[parky]

I feel your pain, my youngest step daughter is currently at university doing a nursing degree. This should be reasonably easy for her as the NHS has a massive archive of papers and practical papers based on real applications in the NHS Trusts but that is still difficult. Finding an actual company that has a system installed, wrote papers about it and willing to allow sharing is probably non-existent. The only thing I think you can do is use one of the companies that supply equipment for example Danfoss and AB as examples. It is unlikely you can find a company that has an installation and publishes it. Based on this you could argue that practical actual installations are almost never published but companies like those mentioned use this protocol and supply documentation on design and implementation. sorry I cannot be of any more help. With a bit of luck, someone on here may have some useful links.

 

[CommissioningMan]

I don't know if it's proper evidence, but what about something like case publications from vendors? Like this one from Beckhoff. (PDF)
It mentions the end customer, shows pictures of the plant, describes the network technology used and how it's used. Springled with copious amounts of vendor specific techno-babble of course.

 

[mad4x4]

I would suggest you watch something like this and work from there -> https://www.youtube.com/watch?v=q8jkLGKFTK8

 

[Etech1]

Pulling my hair out with this now to be honest. I have spoken with my course tutor who confirms I need to supply evidence of 2 seperate specific network installations clearly stating the topology and the protocol of both. I dont feel like this is actually a realistic request. Where would you possibly find such documentation and why would anybody publish it? Finding it completely ridiculous that after 18 months of work being marked at distinction grades I could end up failing over something so silly.

 

[CommissioningMan]

It does seem like a rather unreasonably request. If I was allowed, I could give you the first 500 sets of "evidence" with network topology and all, but I can't, since they are not yours to have. They are, of course, company/customer property.

Perhaps you could contact a local plant or integrator, explain your situation, and ask if they have drawings from old decommissioned machines with something like Profibus, that you can reference?

 

[rpoet]

Pulling my hair out with this now to be honest. I have spoken with my course tutor who confirms I need to supply evidence of 2 seperate specific network installations clearly stating the topology and the protocol of both. I dont feel like this is actually a realistic request. Where would you possibly find such documentation and why would anybody publish it? Finding it completely ridiculous that after 18 months of work being marked at distinction grades I could end up failing over something so silly.

Your instructor is an a$$. PM me; I'm happy to send you a few drawings that show some simple industrial networks, with COMs protocols listed.




-rpoet

 

[Etech1]

Thankyou to everyone for their help. I finally think I have cracked it. My colleague has supplied me with some documents like the ones rpoet was offering so just waiting to put my paper in to be marked now. Hopefully it was enough. Once again thankyou!