1769-AENTR communications loss

[moistcat]

3x 1769-AENTR being polled by 5069-L330ER PLC.

AENT modules are freezing approx once per day each.

• Loss of communications from perspective of PLC
• Web page not accessable from either AENTR ports
• AENT not responding to ICMP ping

The only way to bring the AENTR back online, is to powercycle the device.

While operating normally, the AENTR can be disconnected for a period, and once reconnected, comms is automatically reestablished.

Any ideas? Happening on 3x remote IO racks but all other (x30) ethernet devices (powerflex750 and E+H flow meters) do not have issues.

 

[AlfredoQuintero]

What kind of switches are you using? Are you using managed switches or unamanged? If you are using unmanaged, make sure you configure unicast type of connection from the 1769-AENTR and all other Ethernet/IP adapters to the PLC, because if you select multicast you can flood the switches and cause some devices to not be able to communicate.

 

[joseph_e2]

How old are the 1769-AENTRs? We had a similar issue where the IO was working perfectly until we had to flash the firmware of the PLC. Then we'd see them drop randomly like you're experiencing. Flashing the AENTR firmware fixed the issue.


There are somewhat conflicting tech notes about these modules and flashing the firmware of series A modules to Series B firmware. One note suggests doing it while other says not to for a particular error. In the second note, the "proper" fix was to replace the module with Series B, but we had nothing to lose at that point so we went ahead and flashed them anyway and it has worked beautifully for years with zero issues.



First technote saying it's ok to flash up Series A to Series B FW (access level: TechConnect):
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/49853


Second technote saying NOT to flash to series B to correct connection error 16#0203 (access level: TechConnect):
https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/0509707


The first thing I would try is to make sure the firmware is flashed to the newest version it will support. If it's a Series A module stick with a Series A firmware first. If that doesn't fix it, then try a Series B firmware.

 

[Rockfordmfg]

There is a recall on the 1769-AENTR. Certain date ranges has the issues explaind on Rockwell's site.

https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1136614/~/product-notice-2022-09-001---compactlogix-1769-aentr-may-exhibit-16#0204-fault

 

[BachPhi]

1769-AENTR is an older product, it does not have Unicast option.

@joseph: the two links are for 1794-AENT

 

[joseph_e2]

...

@joseph: the two links are for 1794-AENT

I saw that, but thought that suggesting firmware upgrades would still be useful.