Posted 11 Dec 2006 Hi Guys. I have RSLinx Single Node running on a PC that has 4 available LAN ports. These are configurable as seperate networks. What we are wanting to do is talk to the PLC using DDE on one network, and talk to our own electronics on the other network. This is to be done as two seperate and distinct networks. WHat I need to know is how do i, or is it possible ( or necessary ) to configure RSLinx to only look at the one network connection... We do not want RSLinx trying to ping our other connection as it will cause comms problems for our electronics. The PC we are using is an advantech ARK 3382. I have not investigated setting up the networks on the PC much as yet. Any help would be much appreciated Share this post Link to post Share on other sites
Posted 11 Dec 2006 Setup one of your ports like this. setup links like this. Share this post Link to post Share on other sites
Posted 12 Dec 2006 datman, Interesting delima! I'm not familiar with a "advantech ARK 3382". Didn't know that company made PCs. Anyhow, I vaugely remember setting up a Compaq PC that had 2 Ethernet ports. One was for Linx, the other for LAN traffic. Most software developers don't think to include an option for selecting which network port is to be used when setting up connections. My guess is because most PCs only have 1 port. I think I just pulled all the cabels from the ports I didn't want Linx to use & then setup the PLC ethernet connection. RSLinx just took the only "Active" port it could find. After that was done, I just plugged the other network cable back in & life was good. I don't know if this is the proper way to it or not. There may be a better or more dependable way, if there is I am not aware of it. Sounds like a call to Rockwell support may be in your future. BD Share this post Link to post Share on other sites
Posted 12 Dec 2006 If it uses Ethernet/IP, you are screwed. Ethernet/IP is "chatty". The "autoconfigure" function is caused by broadcast packets. If it uses PCCC ("Allen Bradley Ethernet"), no problems. There is no broadcasting. In your PC's network configurations, each subnet (LAN) should have a different IP address range. The subnet masks determine which network to route a particular packet onto. RS-Linx has nothing to do with it at that point. Say your networks are 10.1.x.x, 10.2.x.x, 10.3.x.x, and 10.4.x.x. Then your subnet masks will all be "255.255.0.0". When the PC (RS-Linx has nothing to do with it) receives a packet to route from RS-Linx, it looks that the first two bytes (10.??) of the IP address and sends the packet to the appropriate network. NetDDE by the way is also chatty as all getout as DDE automatically broadcasts all the time. This is how it automatically acquires name spaces (machine names). I don't know if it is really possible to stop this because you can't use raw IP addresses with DDE. This is again not an RS-Linx related issue. It's a protocol issue. If you have a hardware firewall in the mix somewhere, you could also easily kill the UDP broadcast traffic by selectively controlling the traffic. Share this post Link to post Share on other sites
Posted 12 Dec 2006 Try to disable all enet ports save the one connected to the PLC. Disable thru device manager. RSLinx should automatically look at the configured port for this. Keep the subnets of the 2 LANs separate. Should not have a problem. In case there is still mixing use a hardware / software firewall to restrict traffic. Never practically tried this but might work. Let me know cuz it might be useful to me in the future. Share this post Link to post Share on other sites
Posted 13 Dec 2006 use this setting as Paulengr Say your networks are 10.1.x.x, 10.2.x.x, 10.3.x.x, and 10.4.x.x. Then your subnet masks will all be "255.255.0.0". When the PC (RS-Linx has nothing to do with it) receives a packet to route from RS-Linx, it looks that the first two bytes (10.??) of the IP address and sends the packet to the appropriate network. Use ethernet devices driver in rslinx Share this post Link to post Share on other sites