1756-ENBT/A Connection issues

[Kev77]

I am not sure how other members feel but have had issues because in the past because i had them forced on one end like the ENBT and the NIC card was in auto. I heavelly use Hirschmann switches and had a connection issue and found that the forced setting was the issue. It was explained to me that if you force the setting that all equipment need to be forced. They also said that if for some reason 100mb/full is not available then the connections will fail. I watch all my counters on my ENBT cards and after I set them all to auto all my issues went away.

 

[Darkzadow]

I swapped the ethernet switch and set the negotiation to automatic. The negotiation speed stayed 100 and Full. The other card that was not failing when set to auto said it defaulted to half duplex when full was available so I forced that card. All seems good. I have not received any alignment errors or FCS errors. The server applications still refuse to switch to the .100 IP, but the cards seems to behave now. The only thing that bugs me is that the rev 3 1756-ENBT/A card has a 256 CIP message limit while the rev 4 card has 128 limit. So it seems that auto negotiation helped even though the settings stayed the same. Usage percentage even dropped by half. System has been running for years on old settings don't know why it happened.

Thank you,
The PLC Kid, Mark Buskell, and Kev77
For helping me with this issue.

 

[Kev77]

Your welcome...

On my system there are several things that will force a device to 10mb/half.

1. If I have my server set to 100mb/Full and ENBT to auto.
2. If the device that the ENBT is talking to is a 10/mb device.
3. I have fiber converters on my network that have dip switches on them and it is set incorrectly.
4. A managed switch on my network is trying to correct a speed/duplex mismatch or the port is set to 10mb.
5. I made a change and didn't reboot all devices.

As far as the settings staying the same, for the most part they should. You just allow that when needed they BOTH can decide that the speed needs to change. Were you able to look at the servers NIC setup and see if the speeds are forced? If not then I would suspect that it could be in switch somewhere. I have one device that is on my network that is 10mb/half and have never had any comm problems.

 

[Darkzadow]

The server speeds are set to 100/Full. There could be a switch or port that is set wrong. The network here is not exactly organized. In my area alone there are exposed ethernet switches and ports that are not organized and treated in the manner "hey a free port. plug it in there" Issue could have come from anywhere. Just why act up now as opposed to months ago is a mystery.

 

[Kev77]

"hey a free port. plug it in there"

Hey, I've got some of those!