RsLogix/Ethernet/IP - Browsing plant network

Hello, and thanks for providing these forums and taking the time to help us out.

I have a bunch of different Logix5000 and SLC 500 based PLCs hooked up to a plant's IT network.
When using a laptop with a RsLinx Ethernet/IP driver to browse the entire network it happens to crash two pieces of identical equipment in the facility which are both Logix5000 based.
The local equipment in question consists of a 9300-ENA for the uplink which goes to a 2 layer managed switch which then distributes to the PLC, an ASCII Gateway, and about 16 sonic welder ethernet gateways from Schneider Electric(http://motion.schneider-electric.com/products/ethernet_gateway.html).

As soon as I expand to see the contents of the Ethernet/IP driver in RSLinx, both of these machine's Schneider Ethernet Gateways for controlling the sonic welders, crash. The ethernet port communication light on the Sonic Welder Gateways goes from almost a steady green to a periodic pulse and the HMI reports the sonic points being offline. In order to fix the problem I have to ensure the Ethernet/IP driver is no longer browsing the network and the machine's power needs to be cycled.

The only thing I can think of that I may be doing incorrectly is that I am selecting the network adapter and IP address that was assigned to me by the DHCP server in the plant when setting up the Ethernet/IP driver and these sonic welding machines may be at a different third octet then the address that DHCP is assigning me.

If I plug directly into the machine's 2 layer managed switch and browse the network with the same driver,and the laptop's Ethernet adapter settings happen to be left on assign an ip address automatically, and I browse the Ethernet/IP driver contents it will crash the sonic welder gateways. If I manually assign it a local IP address I can communicate to the entire local network in the cabinet without a crash.

I can see how most of the connectivity guides suggest to browse a remote subnet if necessary with the Ethernet/IP driver in order to work properly but if IT has my network divided in such a way, must I always go and cross reference which subnet the devices I want to connect to are on and have to manually set this up before browsing to avoid a crash? No other equipment in the facility is affected as far as I can tell from the simple expansion of the driver in RSLinx.

Thanks guys!

Welcome to the Forum !

My first thought is that there's an unknown interconnection between the networks that generates a "switching loop" when the RSLinx browse packets get sent out.

But the fact that you don't get the same effect when you plug in with a static IP suggests that isn't the case.

I've seen RSLinx Classic behave strangely where it sends out broadcast packets very rapidly (every millisecond) in some circumstances where it doesn't get any responses to its browse initially. I've never nailed down the exact configurations and versions that contribute to this.

But it was very vivid when I capture the traffic with Wireshark.

To troubleshoot this, I think the first step is to install Wireshark and schedule a time to intentionally cause the fault while running a data capture.

Ken Roach said:

Welcome to the Forum !

My first thought is that there's an unknown interconnection between the networks that generates a "switching loop" when the RSLinx browse packets get sent out.

But the fact that you don't get the same effect when you plug in with a static IP suggests that isn't the case.

I've seen RSLinx Classic behave strangely where it sends out broadcast packets very rapidly (every millisecond) in some circumstances where it doesn't get any responses to its browse initially. I've never nailed down the exact configurations and versions that contribute to this.

But it was very vivid when I capture the traffic with Wireshark.

To troubleshoot this, I think the first step is to install Wireshark and schedule a time to intentionally cause the fault while running a data capture.

Click to expand...

Thanks for your reply, I will install Wireshark and capture some packet data, go from there. I will post back once I have some more information. Once again, thank you for your help!

Hi there haven't been able to continue troubleshooting this issue but I've been doing a bit of thinking and have a couple of questions. If my PC gets assigned the ip 10.179.100.52 on the plant network and I add a Ethernet/IP driver to RsLinx and configure it to browse local subnet I am also seeing Ethernet/IP devices with a different third octet such as 10.179.102.xx. Would this not be considered a remote subnet? Could this somehow potentially cause the crash?

Also in regards to your earlier post, Ken Roach, you mentioned your first thought is that a switching loop is happening, but static ip settings tell you otherwise. I'm not sure if I was clear enough on the fact that when I set the static ip, I'm setting it within inside the electrical cabinet without any connection to the plant, so it's not a static IP on the main network just inside the cabinet. Could this revive your first initial instinct about the switching loop happening?

Re-thinking my last post now that I'm awake I understand that shouldn't make a difference. Although the question still stands about subnets and browsing using Ethernet/IP and my IP address would be considered on a different subnet in both cases, when I allow automatic ip assigment to my ethernet adapter locally within the cabinet, or on the plant network, it seems to be common factor here.