Ross

I'm not an expert in Ethernet IP but have had to deal with similar communications issues in controllogix before. Here are some things I've done that have helped. 1) If you are running a continuous task set the system overhead timeslice to 50%. Be careful your scan time will go up and vary more. Alternately you can move everyting to a periodic task set to something like 50 mSec if your process can tolerate it. 2) Make sure your Panelview and RSView tag update rates are 1 second or greater. The less often they ask for data the less traffic on the network. 3) Put all your PLC data in continuous blocks of data AKA arrays. RSLinx optimizes data based upon where it is in memory and if your reading data in the same general area it will read the whole block once and parse out what it needs. 4) Buy RSLinx gateway for the HMI PC (sorry) and set one of the RSView projects (Laptop) to use the remote OPC server. That way only one of the RSview projects is pounding on the controllogix for data. 5) Get ethernet switches that are managed and set them up so that they will only communicate to the ports they need to. Make sure the Switches are 10/100 so that the connection between switches is 100 MB. Here's where IT can help out.