[PFC100 750-8111] BACnet service outage, Kbus error following API network connection

CODESYS
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1

Hello,

Have you ever encountered a similar case?

I am working on a PFC 100 automation unit (750-8111) communicating via BACnet IP with a Panorama 2025 supervision system.

I connect directly via Ethernet to the API to load/modify the code. Once finished, I switch to RUN mode and reconnect the client network cable (connecting it to the supervision server). After one or two minutes, everything stops:

  • The relay outputs return to 0.
  • The I/O indicator light turns red and blinks.
  • The BACnet service goes into « disabled ».
  • On the WBM and Codesys, it indicates a Kbus error, watchdog timer exceeded.

Firmware version: 28
Development environment: Codesys V3 SP19 Patch 7

I know that when my PC is connected, no anomalies are detected. On the client network side, there are no other BACnet communications. The program remains functional as long as the automation unit is not connected to the client network.

Thank you in advance for your feedback.

Screenshot 2025-11-18 144012 (002)

2

Hi, have you tried restarting the runtime?

3

Hello, what exactly do you mean by runtime?

4

In the WBM, in the “Fieldbus” tab → OPC UA → Runtime restart

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