Support regarding PLC M580 over the network

[anupky1979]

Dear Team,

We want your support for the PLC M580, over the network.

Also 1) please tell us if we can have the possibility of removing the broadcasts from the PLC, which are of no use.

        2) and is there any possibility of having two IP ranges in the PLC M580?

Please reply as soon as possible

[Hennie_Smith]

Hi,

Not sure which broadcasts you refer to. As for your 2nd question, you can use BMXNOC0321 with port forwarding with 2 ip subnets to segregate your device and control networks.

BR

[JerryBartlemay]

Broadcasts such as BootP, DHCP and ARP are part of the address server.  The service port of the CPU is part of the EIO system, and even though it doesn't support EIO drops directly, it does support the address server.  If you connect the service port of the CPU to the plant network, these messages will be sent out.

Because these messages are now on the plant network, this means you are cross connecting EIO systems on multiple M580s, never a good thing.  Hennie is spot on; using the BMXNOC0321 will isolate the EIO system, not sending its broadcast messages, and give you multiple IP subnet support.  I've attached my white paper on M580 architectures that addresses these questions.

[anupky1979]

Hello All,

We are facing some instability issues in the network setup shown below, where one of the devices PQ meter keeps disconnecting intermittently and reconnects after a short while. This behavior then repeats periodically.

The network looks like below - 

Our Observations and Queries-

1. Excessive Broadcasts in the Network

Upon analyzing the network traffic using Wireshark (via port mirroring on the Advantech switch), we observed a significant number of broadcast packets being sent across the network.

• Many of these broadcasts appear to be unnecessary for the PQ meter.

• Below is a snapshot from the PCAP file showing a few IP addresses that are generating broadcast traffic very frequently (though there are others as well):

Our Request:
Is there a way to suppress or disable unnecessary broadcast traffic from the PLC M580, particularly if it's not essential for device communication?

We suspect this excess broadcast traffic could be impacting the stability of the PQ meter’s connection.

2) Network Segmentation via VLAN

To further isolate and stabilize the PQ meter's communication path:

Query:
Does the PLC M580 support dual IP addressing or VLAN configuration?
If so, can we configure two IP ranges one for general PLC communication and another isolated VLAN specifically for the PQ meter to avoid interference?

In total that is what needs to establish, PQ meter connected well to PLC M580, so that it never disconnects due to any setting from PLC. 

[anupky1979]

Hello,

I have updated the whole scenario, please have a look into it and let me know what i can do about it.

[anupky1979]

I have elaborated the issue, please have a look and let me know what to proceed with.

[Hennie_Smith]

Hi,

The M580 cannot be configured with Vlan. We still need bit more information.

1. What protocol are you using to communicate to the PQ meter?
2. Does the PQ meter support EthernetIP or DNP3?
3. In your trace, could you provide the IP addresses for the equipment mentioned? The PLC in particular try to establish communication to a number of different IP's unsuccessfully on Layer 2 which causes the ARP messages.
4. Are you communicating from the PLC via a NOC card or from the CPU port? Can you capture a trace with the service port of the NOC/CPU set as mirror port?

If you want to isolate the comms to the PQ from other communication you would need to have a dedicated NOC301 card with separate connection to the switch. The Advantech switch need to be configured to Vlan tag all communication from the PLC on that port. You would need additional managed switch before the PQ meter to untag the vlan if the meter does not support vlan configuration itself.

Hennie