Problem Networksetting NUA0100

[EricZero]

Hello everyone,

I am having an issue with setting up the BME eNUA0100, specifically with configuring the IP address and gateway. The system is integrated into a VLAN and therefore has a specific IP address range, subnet, and gateway.

The following hardware is being used:

• BME M580 eP581020
• BME eNUA0100

In Control Expert Classic (V.16.0), I can't find a way to manually set the gateway for the eNUA0100. In the "Ethernet Network" window, an address is displayed in the "Gateway" column, but it's the same "IP address A" of the eP581020.

When I configure and try to use the front port of the eNUA0100 with the given addresses, I receive an error message.

As a comparison, with the NOR2200, it's possible to manually set the IP address, subnet, and gateway. When I connect directly with my laptop via LAN cable, I can easily reach the eNUA through the service port.

My questions are:

How and where do I need to adjust the settings to access the eNUA0100 through the service port of the eP581020?

Why must the IP address not be in the same subnet?

Many thanks in advance.

Here are a few screenshots:

[Trinxs1]

There are two ports on the NUA module.  The backplane must be in the same subnet as the CPU for it to exchange data via the ethernet backplane of the CPU rack, and the CPU is the gateway for this.

The control port on the front (I assume you are using IPV4) if activated must be in a separate subnet to the CPU.  This is why you are getting an error, or it will not allow you to change the gateway address.  If you choose a different subnet for the control port you will have full control over the gateway address.

[EricZero]

Thank you for the quick response, Trinxs1.

I likely didn't explain my issue clearly enough. The network settings are provided by our IT department, so I'm not supposed to use a different subnet.

My problem is that I cannot access the NUA over the network via the service port. Ping is not possible, nor is OPC UA.

However, if I connect directly to the CPU with a PC using a LAN cable, I can reach the NUA without any issues. But I believe that's not really the intended purpose.

What I also don't quite understand is why there is no option to manually configure the network settings. This is possible with the NOR2200, which I can also access over the network through the CPU's service port.

[ciupol · Accepted solution]

The problem with your configuration is that you are trying to put IP addresses in the same subnet for both backplane port (network) and control port. Those addresses need to be in different subnets.

In your example I assume IT gives you an address from subnet 10.7.28.0 with mask 255.255.252 and gateway 10.7.31.254. Allowable IP addresses for such subnet are 10.7.28.1 to 10.7.31.254 (last one used for gateway already). You have to assign one of those addresses to NUA control port in NUA module configuration. So from screenshot let's assume we leave what you have here:

Now problem in your case is with IP addresses for the backplane port and for CPU. Those addresses have to be on different subnet. They can't be from range 10.7.28.1 to 10.7.31.254. This subnet will not be accessible to your IT so you can pick up addresses without them. Here is example of possible configuration. For CPU:

For NUA:

And you ethernet network screen (I have here also one EIO drop):

[Trinxs1]

With respect to the NOR module depending on the hardware version, if it is the version with only one ethernet port (i.e. the back plane) and a serial port on the front the only way you can access the module via ethernet has to be via the CPU backplane.

Ciupol has provided a response which hopefully clarifies a solution.  The important item for the NUA module is segregation of networks.  The CPU backplane should be isolated from the layer above.  You can however filter communications that will allow devices above to access the CPU via the control port of the NUA once you have security enabled and the appropriate filter enabled.

I hope this answers your questions.

As 

[EricZero]

Ok, Trinxs1 and Ciupol, thanks for the explanation.

I'll speak with our IT again to see if something can be done. It might also be due to the firewall that I'm unable to access the NUA from the CPU port over our network.

Unfortunately, in your images, Ciupol, only a yellow triangle is visible, so I can't see the examples.

Thanks for the info on the new NOR hardware Trinxs1. If it's going to be the same with NOR Ver.2, we'll need to find an internal solution first before we switch to the M580.

[ciupol]

EricZero,  not sure why you can't see the images. Here are they once more attached to the post.