Auto Negotiate
I agree with Ken Roach.
We had an installation with 2-Compact Logix and a mix of 3rd party devices.
The system worked great in SE Michigan at start-up. The system worked great at start up in mid USA.
Later, On-Site, The PLCs were connected to plant network for critical manufacturing build recipe requirements, and then the **** hit the fan.
Ethernet Lock-ups became intermittent, but frequent, could not diagnose even via alternate DF1 serial connection. Power cycles were required about every other day.
On-line Ethernet diagnostic showed: a never ending stream of FCS errors.
On-site, we tried using managed switches with diagnostic capabilities to try to find the source of FSC errors, but were still stymied.
The customer was at limited volume, so this was inconvenient, but resolve was required. Then, one day, after much screaming, by us to our RA vendor, we had a ROOM FULL of RA distributor engineers, AND RA networking engineers. We were off-site in our home State, we made a VPN connection to the problem site. We uploaded and saved the PLC program and settings.
We examined and observed that the PLC network settings that had the check box for auto negotiate was un-checked. HHmmm? We checked the BOX for Auto Negotiate, had the remote customer stop the equipment, performed a download, with the new auto-negotiate setting, and the restarted the processor.
Using diagnostics we saw ZERO FCS errors. And the lock-up NEVER happened again.
As an integrator, we were totally undressed and embarrassed, that after weeks of trying this, and trying that, and spending monies on managed switches, that a simple “check-box” with the PLC configuration solved ALL of the Ethernet lock-up problems.