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VK_146337003-Newcomer
3-Newcomer
July 22, 2026
Question

ControlLogix Ethernet driver — repeated project upload failures / "device not responding" on legacy CompactLogix

  • July 22, 2026
  • 1 reply
  • 28 views

Experiencing intermittent communication failures across multiple devices on the Allen-Bradley ControlLogix Ethernet driver.

 

Environment:

  • Product: ThingWorx Kepware Server [version, e.g. 6.x — check Help → About]
  • OS: [Windows Server version]
  • Driver: Allen-Bradley ControlLogix Ethernet
  • Affected devices: 1769-L23E-QBFC1 (CompactLogix 5323E), firmware revision 20.12, connected via embedded EtherNet/IP port, connection path <IP>,1,0
  • At least 6 devices affected across multiple channels (CH_3, CH_4, CH_9, CH_13, CH_14, CH_15, CF_2), IPs in the 10.16.70.x range

Symptoms (from Event Log, 21/07/2026, 15:07–15:37):

  • Warning: "The following errors occurred uploading controller project from device. Resorting to symbolic protocol." — repeating every ~10–15 seconds per device
  • Warning: "Device is not responding. | ID = '<10.16.70.x>,1,0'."
  • Warning: "Frame received from device contains errors." (device CH073, 10.16.70.114)
  • Between failures, the driver successfully reads device identity (Details events return correct Vendor ID, Product code, Revision, S/N), indicating the connection is partially working

The pattern per device is: identity read succeeds → project upload fails ~3 seconds later → "Device is not responding" ~15 seconds after that → identity read succeeds again. The driver appears to be in a continuous retry loop re-attempting the controller project upload.

1 reply

M
MRohillaCommunity Manager
Support
July 28, 2026

Greetings ​@VK_14633700 ,

 

Hi,

Thank you for providing the details of the issue.

Based on the information shared, it appears that the driver is able to establish communication with the controller and successfully retrieve the device identity. However, the communication is interrupted during the controller project upload process, after which the driver retries the connection. To help determine whether the issue is related to the network, controller, or driver configuration, we would appreciate if you could check the following information:

  • The exact Kepware Server version and build number (Help → About). Upgrade to the latest V7.1
  • The Windows Server version on which Kepware is installed.
  • Confirm whether Automatic Tag Generation (Controller Project Upload) is enabled for the affected devices.
  • Has this issue always existed, or did it begin after any recent changes such as a Kepware upgrade, PLC firmware update, network modifications, or project changes?
  • Are you able to browse and communicate with the affected PLCs consistently using Studio 5000 or RSLinx while the issue is occurring?
  • Please collect and share the following diagnostics captured during the problem:
    • Kepware Event Log
    • OPC Diagnostics log
    • A Wireshark network capture from the Kepware server while the issue is occurring (if possible)

Additionally, if you have access to the PLC diagnostics, please check and let us know:

  • The controller CPU utilization or task load.
  • Whether any controller faults are present.
  • Whether the issue affects all controllers simultaneously or only specific devices at a given time.

This information will help us determine whether the issue is related to communication reliability, controller responsiveness during project upload, or a compatibility/configuration issue.

We appreciate your cooperation and look forward to your response.


Best regards,
Technical Support

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