TigerLily Posted February 11 Report Posted February 11 Hello, I have a project I am working on that requires a CJ2M-CPU34 to communicate with a NX-EIC202 remote IO rack over Ethernet/IP. The PLC has been in the field several years, it has the IP Address 10.128.207.122. The customer assigned the new remote IO an IP address of 10.128.208.201. I thought if I changed the subnet of the two devices to 255.255.254.0 they would be able to communicate but so far I am not having any luck. Has anyone successfully done something like this? Any advice would be greatly appreciated!! Quote
Chris Elston Posted February 11 Report Posted February 11 My gut reaction would be the same, so long as there is not a routing issue the subnet mask would be 255.255.254.0, however if you want to try a broader mask try this one: 255.255.252.0 (/22) which should include both addresses in the same subnet when you look at the binary. Quote
TigerLily Posted February 11 Author Report Posted February 11 I tried setting the subnet to 255.255.252.0 but still no luck, I am testing with two CJ2M-CPU33 PLCs I have laying around. I changed the subnet but when I connect with Network Configurator via USB it only sees the PLC it is connected to, I tried connecting to each separately and transferring the network configuration but then I get the Er D5 with the other PLCs IP address. Quote
Chris Elston Posted February 11 Report Posted February 11 You have a Gateway defined in each case, is that a router for both separately or the imaginary one we all put in there. (What gateway?) LOL. If they are connected to the same switch, try changing the subnet mask on your PC and pinging both from your PC. If so, I think the mask is correct, but I am wondering if there is a router, that it's not routing traffic or separating the two on VLANs? Just a few thoughts. Quote
TigerLily Posted February 11 Author Report Posted February 11 Ah, the gateway is what the customer gave me to use on site I put it in without thinking, I can take it out for now. I tried changing the subnet on my PC but can only ping the one that matches the third octet I use in my PC's IP address, I am going through a Phoenix Contact unmanaged switch right now. FL SWITCH SFNB 5TX - Industrial Ethernet Switch Quote
Solution TigerLily Posted February 11 Author Solution Report Posted February 11 I tried changing the subnet to 255.255.0.0 and that seems to work now, with all subnets set to that I can ping both controllers from my PC and they are talking over Ethernet/IP. Thank you for your help!! Quote
Chris Elston Posted February 11 Report Posted February 11 13 minutes ago, TigerLily said: I tried changing the subnet to 255.255.0.0 and that seems to work now, with all subnets set to that I can ping both controllers from my PC and they are talking over Ethernet/IP. Thank you for your help!! When in doubt, OPEN THE FLOOD GATE! lol... Glad it worked. Quote
Sergei Troizky Posted February 27 Report Posted February 27 On 2/11/2025 at 1:51 PM, TigerLily said: ... they are talking over Ethernet/IP. So, with or without Gateway? Quote
BachPhi Posted February 28 Report Posted February 28 Instead of open the floodgate, subnet 255.255.224.0 should do it. Quote
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