Scan Device on different subnet BMCNOC0321

[eldod16]

Hi, 

I need to scan a device (DTM) on a BMENOC0321, but the device is on a diffrent subnet than the NOC card itself. 

How can this be acoomplished?

*Note: There is a router on the network and the traffic can pass. 

*Note: This can be accomplished using a BMENOC0301 card, but my application limit my options.

Running BMEP584040 Control Expert 14.1

[Siddiqui]

Hi @eldod16,

Please share the network architecture along with the IP address schemes and how the different nodes are connected. It becomes easy to understand and answer to your request.

BMENOC0321 came with the IP forwarding feature, and this module can support up to three subnets.

I don't know how this module is configured inside the ECE (Control Expert) in your configuration.

When you said that this could be accomplished with the BMENOC0301 card, could you please explain this, or when you are trying to configure device scanning in a different subnet using BMENOC0321, you are facing an error inside the ECE? If that is the case, please share the error message.

NOTE: The control ports, which are Port 2 and Port 3 of the BMENOC0321 module, are the ones able to scan the devices either using Modbus TCP or Ethernet IP.

I did some configuration in my setup, but I am using ECE V 16.0.

In my configuration, I am not using the IP forwarding feature inside the NOC0321 module to make it simple.

For example, the control ports (Port 2 and Port 3) of the NOC0321 module are in Network A. Check the snapshot for your reference:

IP Address: 172.168.12.1

Subnet Mask: 255.255.255.0

Gateway: 172.168.12.10 (This is the Router IP address where the BMENOC0321 is connected with the Router port)

After opening the DTM configuration of the BMENOC0321 module, I added the Generic Modbus TCP inside the DTM and did the following configuration:

IP Address: 192.168.12.3

Subnet Mask: 255.255.255.0 (Grey out)

Gateway: 172.168.12.1 (Grey out)

NOTE: DHCP is disabled by default for this generic Modbus TCP device. I enabled the DHCP option, corrected the GATEWAY IP Address, and deactivated it again.

The Ethernet Network Manager summarises the BMENOC0321 control port Network and the Modbus TCP device network address.

I managed to build the ECE project with just a warning:

I believe this should work as the BMENOC0321 module should pass scanning Modbus TCP device information to the gateway address, and for the rest, the router does the job. You have to make sure that the proper gateway configuration is done on the other side of the router where the device is connected.

NOTE: I never tested such configuration by myself. Theory-wise, it looks good, but I recommend you do the test to make sure it works. If you are facing issues, please collect the Wireshark logs and share them with me. Even if you plan to enable the IP forwarding feature inside the BMENOC0321, the device scanning should be the same as explained above.

I hope the above comments will provide help.

BR,

MWS

[eldod16]

Hi @Siddiqui 

Thank you for your nice detailed answer. 

The method you have described is what I normally use when doing such scanning on different subnets from a BMENOC0301. 
The issue i am facing is that when doing this on a BMENOC0321, ECE won't allow me to save the IP setting for the DTM. For the sake of testing, i repeated the exact same steps as you on a new project. The NOC0321 is not configured for IP forwarding.

I am starting to think this might be a limitation of ECE v14.1, I will try to install and test this on V15.3

Thank you

[Siddiqui]

Hi @eldod16,

Yes, I agree with you. This limitation seems to come from an older version of ECE 14.1.

Using ECE V15.3, after adding the BMENOC0321 module, followed by adding the device using DTM and then trying to change the IP address of the device into a different subnet, which is not possible in the ECE V15.3.

Check the snapshot for your reference:

We also repeat the same steps using ECE V15.3 with BMENOC0301/0311, which allows the scan of devices from different subnets but not for the BMENOC0321.

In my earlier post, I shared that ECE V 16.0 allows the scan of devices from different subnets for BMENOC0321. It seems that from ECE V16.0 and onwards, all the modules BMENOC/0301/311/0321 support this feature.

NOTE: I suggest you perform the test with ECE V16.0. I was looking at whether there might be any HF for ECE V15.3 that might allow the BMENOC0321 module to scan the device from a different subnet, but I was not able to find it. You can also try it.

I hope the above comment provides help.

Best Regards,

MWS

[Trinxs1]

V15.3 supports allocation of a EIP and Modbus TCP device to a BMENOC0301/311 which is in a different subnet.  Expert V16 supports this for a CPU as well.  I have tried adding devices to a BMENOC0321 in V16.0 and confirm the project builds when I use EIP and MBT devices located in a different subnet to the BMENOC0321 module.
You will need to make the EIP communications point to point and not multi-cast. It is unusual that once the change was made, I had to enable the address server and then disable it to refresh the configuration screen.  The gateway IP address has to be in the same remote subnet for the EIP changes to be accepted, however with the MBT there was not option to change.  Attached is a screen shot of my configuration which has EIP devices connected to ethernet modules including the CPU with IP addresses in a different subnet.