Ethernet noise reduction strategies
Ethernet noise reduction strategies
(OP)
I have an HMI on a peice of equipment that routinely crashes (at least once per day) whenever the Ehternet cable is plugged in. I suspect noise from nearly equipment is corrupting the WinCE based HMI. Are there any strategies for reducing the noise coming into an ethernet port? I breifly looked for filters however was not able to find anything, other than isolators. This is a test site for a product we are releasing soon and I would like to have some potential solutions and advise at hand for customers who may experience issues such as this.
As always, ny advise is much appreciated.
As always, ny advise is much appreciated.





RE: Ethernet noise reduction strategies
Have you considered an optical interface?
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RE: Ethernet noise reduction strategies
What kind of machine is the HMI being connected too and what is the separation distance between the two?
How do you know the HMI is crashing?
Have you figured out why the HMI is crashing? Does it crash if you have the HMI completely ignoring any signalling on the Ethernet?
Is the HMI in a conductive enclosure?
Is the HMI mechanically grounded to something?
Where is the power for the HMI originating?
Keith Cress
kcress - http://www.flaminsystems.com
RE: Ethernet noise reduction strategies
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RE: Ethernet noise reduction strategies
Keith Cress
kcress - http://www.flaminsystems.com
RE: Ethernet noise reduction strategies
As for my own situation, we installed an ethernet isolator going into the HMI yesterday. Withen a few minutes, we had a situation. I forgot to tell the installer to turn off power to the HMI before doing the install, so it was my immediate hope that connecting to a live panel caused the issue. I rebooted the HMI remotely, and last night it ran all night without an issue. Up until then, with the ethernet installed, it had been crashing every night at around end of the last shift. So far, my hopes are sustained. Time will tell.
I am assuming that the ethernet installation is less than ideal, and, as a test site, it's likely to reflect reality for some of our future customers. With that in mind, I am having them keep the cable routing the same for now so I can test the effects of the isolator, as well as, any other hardware that might positively effect the situation (any ideas). Once we run out of ideas, I will have them reroute the cable.
I hope that clarifies the post a little, and again, thanks for the feedback, and keep it coming.
Now in response to itsmoked's generous query
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That's fairly interesting since typically the only connection between the two communications locations is something like a 1000 puff capacitor to the chassis.
What kind of machine is the HMI being connected too and what is the separation distance between the two? PLC, located inches away in the same enclosure via a 6 ft serial to din cable
How do you know the HMI is crashing? WINCE error window from the operating system
Have you figured out why the HMI is crashing? Does it crash if you have the HMI completely ignoring any signalling on the Ethernet?Disconnecting cable appears to resolve issue
Is the HMI in a conductive enclosure?No, Nema 4X plastic enclosure
Is the HMI mechanically grounded to something?Only at the 120V input to the HMI/color]
Where is the power for the HMI originating?[color #CC0000]Local 120V sourced from step-down transformer connected to 460V mains in a seperate eclosure
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RE: Ethernet noise reduction strategies
So it looks like the OS (Win CE) has the issue. It could be an isolation issue. Are you using a shielded Ethernet cable?