Ethernet networking questions

[Mark Snodgrass]

Looking for links and info on ethernet networking, in particular isolation and managed switches. Our network is getting too big and is starting to cause issues.

Thanks in advance

Mark

 

[The Plc Kid]

Here http://lmgtfy.com/?q=isolation+and+managed+switches

 

[The Plc Kid]

All joking aside it depends on what you have on your network? Siemens,Rockwell,etc and protocols Ethernet IP,profinet, Modbus TCP-IP, Etc.

In older rockwell firmware Below V17 and V18 running Ethernet IP on your network of any size it was hard not to have a managed switch but even with new firmware being Unicast by default I still recommend a managed switch if budget permits because of the diagnostics you get.

You can do segregation using many methods but VLAN's are best for this line of work IMHO and it is esier to do ina managed switch rather than using a dedicated router so another reason to go for a managed switch.

There are layer 2 and layer 3 managed switch units and as you may guess layer 3 costs more but if you need to comm between isolated VLAN's then a layer 3 managed switch is the best route.

 

[Mark Snodgrass]

Thanks Kid,

I already googled and found a few articles. I am in a sawmill, and we have multiple PLC5s and a few SLC500s, the planermill has Contrologix and is working ok. As we are upgrading sawmill equipment, and more of it becomes Ethernet dependent, we are starting to run into communication issues as everything (including the offices, both locally and corporate) is connected. We want to be able to have the actual process controls separated from the general network, but still be able to access the PLCs for data and/or troubleshooting purposes.

Thanks Again!

 

[The Plc Kid]

IMHO you need process level switches and a core switch that you control as well as a firewall seperating the equipment network from the corporate. From there you create rules that allow specific access to the equpment network from the outside(internet remote access)and from the corporate LAN.

You may want to have desktops and laptops that sit directly on the equipment network jsut for engineering and maintenance only.

In most caseas you want to have a DMZ between the equipment network and the corporate network and things that both networks need access to should sit there. Examples being data historians, batch historians, batch controllers, Version control servers,etc.

I also recommend VLAN segregation of the equipment network between major lines and processes also as this helps to keep problems isolated so they don't migrate to other areas.

This method works well for me. I have a little over 800 processors and over 3000 drives and I would guess around 300 HMI on this site betwenn 5 buildings and when I came here nothing was networked and now about 80 % of it is and I don't think I could manage it without being networked.

 

[The Plc Kid]

There is some really good stuff here http://www.ab.com/networks/architectures.html

 

[Mark Snodgrass]

Hey Kid,

would you be willing to make a trip to NC for a day or two to help tutor us on what you know, to get us started in the right direction? Myself and the other PLC tech here have been trying to upgrade our systems here, and it looks like the network is our next major project.

Thanks,

Mark

 

[The Plc Kid]

Mark

I appreciate the offer and would love to be able to take you up on it but I am a full time college student and I work 50+ hrs a week here to keep my head above water and being the only EE here it would be difficult for me to do that at the moment but if you will PM me with your contact info I will do the same and I would be happy to help over the phone and email if you would like.

I think with some good communication between us we can get you where you want to be with getting your plant networked.

 

[BobB]

You have a really good supplier of managed switches in the US up to level 3 in Westermo - they are really good.
I also use NTron from time to time and they have been good too - Westermo level 3 in particular is a bit more available in Oz than NTron that is all.