1756-ENBT Control Flash

[Tmac2490]

I have a 1756-ENBT which I would like to flash up to the latest revision. Right now we are getting many FCS errors showing up, sometimes our communications to our HMI's and other devices pause for up to 20 seconds. Would the FCS errors cause this? I believe the revision now is 2.4.

 

[nhatsen]

Right now we are getting many FCS errors showing up...

So there was a time when the system worked fine, right? Before changing the firmware I would look for any recently hardware change.


TN29328 Ethernet Alignment and FCS Errors (Access Level TechConnect)

TN 490068Intermittent loss of communications between Logix processor and Ethernet I/O (Access Level: TechConnect)

 

[Tmac2490]

That is helpful, thank you.
A portion of that article,

The Alignment and FCS errors are detected when the full-duplex port will transmit without listening, and this will sometimes corrupt the messages transmitted by the half-duplex port.
If a hub or unmanaged switch is utilized, then all devices need to be configured for Auto Negotiate.

We have an unmanaged switch in our configuration, I had set all other devices to fixed full/100, to correct a different issue, perhaps I created a new one!

 

[nhatsen]

Here is an interesting discusion about Auto Negotiate vs Fixed Speed and Duplex:

http://www.plctalk.net/qanda/showthread.php?t=74607

I have to add the "guy from Rockwell" to the mythical beings list, between bigfoot and slender man.

 

[Tmac2490]

Thank you for that link, very helpful!

 

[JeremyM]

Yep, auto-negotiate and test your cables.

 

[Tmac2490]

I originally had a issues with several Power Flex 525 losing communications and stopping a process. I was advised from, you guessed it, Rockwell to make sure these drives are set to 100/full and all other devices are set there as well. All seemed fine! Then we started getting very long pauses, up to 20 seconds on our HMI's. This is why I started looking down this Auto vs Fixed road! Today I will make sure all unmanaged switches are replaced with managed.

You folks are really helpful and I do appreciate your thought!