One computer Ethernet port for PLC and company network

[A_G]

My customer wants me to set up their industrial computer hmi running factory talk view se client in the following way. They want to use a single Ethernet port for comms to PLC and to the ftvse server. Is this reasonable or is it better to use two separate Ethernet ports?

 

[KuulKuum]

You can utilize a single ethernet port with multiple IP addresses (I think the max is 64).
You could just add the customer's work network IP setting to the existing PLC/FTV SE client PC system network even with separate IP subnets. The company network would not have access the PLC/FTV SE network but the FTV SE Client PC could access both the PLC/FTV SE server as well as the company network.

Now this will not work if the company work network needs access to the PLC/FTV SE server, in that case you would need to assign a single connection to be on the same IP subnet.

Hope this makes sense.

 

[OkiePC]

Does the client even need to talk to the PLC network? Doesn't it just connect to the server?

Our standard practice is to include 2 physical LAN connections, one as DHCP for the business LAN (or ISP) and one for the PLC network configured as a status private IP. But this is for Ignition Gateway computers in most cases which sometimes also run clients.

 

[I_Automation]

My customer wants me to set up their industrial computer hmi running factory talk view se client in the following way. They want to use a single Ethernet port for comms to PLC and to the ftvse server. Is this reasonable or is it better to use two separate Ethernet ports?

The correct answer to them is:

I tried it your way and it won't work.


I usually work on the project a few days and then tell them this.



Also I use this a lot when the boss won't buy the correct component and wants me to get by with something sitting on the shelf he thinks should work.

 

[cardosocea]

My customer wants me to set up their industrial computer hmi running factory talk view se client in the following way. They want to use a single Ethernet port for comms to PLC and to the ftvse server.

Either you didn't explain yourself correctly or your customer knows a fair bit more than you. Do you want to review what you wrote for accurateness?

 

[TheWaterboy]

Same network? Fine.
Different networks? not advisable, multihoming Nics has fallen out of favor in security circles.

 

[A_G]

@cardosocea I think I described it accurately as far as I understand it but I admit Im no expert at computer networking. It's definitely possible the customer knows more than me

Thanks everyone for the responses, I will have to review them thoroughly

 

[James Mcquade]

if the customer wants to see the screen and change the setpoints, timers, data, recipes, NO !!!!!!!
they will change the information and they have no clue as to what the data means ! they don't watch the machine operate.
if that is what they want, then put my warning in an email and send it to the project manager and state that you will not be held responsible for when the machine quits working because someone changed the data.
make a good working backup before turning the machine over.
james

 

[PreLC]

How much traffic do you estimate would be running on this network?
Sounds to me like this is a reasonable request - as long as your network is strong enough to accommodate the load. Be aware that you might have some issues during client|server startup, but that should be okay as long as no machine-critical IO is also being transferred through your network.

 

[cardosocea]

@cardosocea I think I described it accurately as far as I understand it but I admit Im no expert at computer networking. It's definitely possible the customer knows more than me

Usually the FTView Server talks to the PLC and it's very common for that machine to have two or more NICs so that networks are split. However, the client doesn't talk to the PLC directly, talks to the SCADA server so it really doesn't need more than one NIC for most common applications.

 

[A_G]

@OkiePC @cardosocea if the PLC does not have to talk to the client directly, I guess this explains it

Thanks everyone

 

[joseph_e2]

How much traffic do you estimate would be running on this network?
Sounds to me like this is a reasonable request - as long as your network is strong enough to accommodate the load. Be aware that you might have some issues during client|server startup, but that should be okay as long as no machine-critical IO is also being transferred through your network.

This. In addition to the security concerns, traffic is an issue.



War story: we had a machine with a ControlLogix talking to a Flex IO chassis. It all worked fine until the network jack was plugged in, at which point the Flex adapter would drop, reconnect, drop, reconnect, etc., until the connection to the LAN was removed. Proper fix was to isolate the physical networks. Even with the PLC and Flex adapter on a completely different and non-route-able subnet, the traffic killed the connection. This is one of those things that can work for a while, or most of the time, until something "random" happens and kills it momentarily. Like, say, IT pushing out OS updates, or something like that. If they want it that way...fine...I guess. I would warn them of the pitfalls and dangers before releasing it, though. Is a second NIC really that big a deal? I'd be curious why they don't want one.