Ethernet Issue I'v never seen before

[mike590 1]

Ok this is my first time posting here so go easy on me if I'm in the wrong place. I have a 5 port ethernet switch in a control panel that is connected to an HMI, 5/05, and up to the roof switches for the rest of the network. I went to the panel to go online with the processor and plugged in my ethernet cable but then my touch pad on the laptop would not respond so I pulled the cable out and it started working just fine. After that I changed ports on the switch in the panel and had the same problem. Finally I go to my office and try to connect to the same processor from there and it worked just fine. Anyways I was wondering is there to much traffic on that switch or is it just bad all together, the machine is running production right now otherwise I would have tried a new switch all ready. Thanks for your time

[waterboy 7]

The TOUCHPAD stopped working after plugging in an ethernet cable ? Thats bizarre.

[y2kmfic 3]

I don't have an answer, but you know what they say.. misery loves company. Google: mouse touchpad Ethernet You're not alone :)

[Ken Roach 194]

I suspect this is related to electrical noise, rather than to the controllers or the network traffic. I've had this sort of thing happen with USB/RS232 converters connected to servo drives; as soon as the drive is enabled, my touchpad goes unresponsive. Sometimes I can get better reliability with the PC running on batteries, sometimes not. External wire-connected USB mice seem more reliable than touchpads, but sometimes the problem also affects the keyboard. Some network noise problems or ground loop problems are easier to work around than to solve; I've installed tiny WiFi access points, or used RS-232 isolators, or used fiber optic converters just to make sure my computer's port is not electrically connected to the control system.

[mike590 1]

Thank you Im pretty sure you are right now, today I came in when nothing was running and plugged in and it was just slightly responsive. It was very aggrevating but I got what I needed to done. Now do you think this could cause a problem on the rest of my network overtime? I haven't had any problems (that I know of)yet but I have about 150 PLCs on this network, thats not counting the screens and drives. but what do you think?

[Shiner 2]

I have had similar issues connecting to Ethernet applications, but noticed something else. If the laptop was on a table, or any other working surface, the touch pad was unresponsive. If it was in my lap, I got my response back on the touchpad. It is only a guess, but could the RF emitted by the Ethernet cable be creating a charge on my body that interferes with the touch detection system of the pad? Then as soon as the laptop is equalized to my potential being in contact with me, the problem goes away? I do not have one, but someone experiencing this should try wearing an ESD strap attached to the laptop to see if the problem is alleviated.