Ethernet Traffic & PVP lockups

Hi, I'm currently looking at an Ethernet network containing approx 10 Micrologix 1100 processors and 3 Panelview plus HMI's (all running the same application but generally viewing different screens and only one has active data logging). The network is physically laid out over a production line using 5 port CTRLink EISK5-100T switches (approx 10) to "daisy chain" the Ethernet network down the length of the production line. The PLC's and HMI's are patched into these switches at various points.

With basic projects in the HMI's the screens tend to operate fine, but once trending, data logging and heavier use of the alarm feature are added the panelview’s tend to lock up - each screen has the current time displayed for reference and this freezes up periodically approx every 1-2 minute for a period of 1-2 minutes the buttons still function in respect that when a button is pressed while locked up when the screen unlocks the button action occurs. I have looked through Rockwell’s knowledgebase and "tuned up" trending and data logging. I have spoken to Rockwell tech support and they believe it will be a network issue, they have asked that I look at the PLC -> PLC messaging which I am in the process of doing to see if messaging between PLC’s can be better managed to improve the network traffic.

I have noted that if a panelview is disconnected form the network then although the screen is not functioning by updating variables it does not lock up at all, it then looks to me like an issue with the data server when not connected it can’t update and therefore doesn’t lock up but when connected is able to update but is slow due to network traffic issues and this reflects in the screen locking up.

Can anyone advise on possible fixes?

I have also been looking into an Ethernet traffic analyzer “Ethereal” (a free web download app) but am a little short on knowledge on what to look for, can anyone advise on this and what to look for?

Thanks in advance!

Apologies for the length of the post.

I would think this is network related. I'm not familiar with that switch, but from what I read on the internet, it sounds like it would work ok. We have many more PLCs and HMIs on our network without those issues.

Ethereal will give you a lot of information that is hard to understand, but it is a good product. Look for IP addresses that come up a lot. Those would be your suspects for problems.

Good luck

Our network is laid out in a ring. We have Hirschmann switches with the redundant ring function, so all data does not travel the shortest path. One thing that helps us is that most of our PLC to PLC com is contained within the local switch in the area. There is not a lot of messaging passing through multiple switches, and that was done by design. We do pass a lot of data to PCs though. There a several nodes in each area getting data from a server in the office that gathers the data from all of the locations.