Internal PROFIsafe Error

What does 8706 mean?

A critical internal error has been detected within the PROFIsafe communication stack or functionality of the Safety PLC. This error directly compromises the PLC's ability to participate in safe communication and to process safety-critical data from other PROFIsafe devices. The entire safety system's integrity is at risk.

• PROFIsafe F-Address conflict or incorrect F_Address assignment for an F-device (safety device) on the network.
• Checksum error (F_iPar_CRC) or data integrity failure detected in PROFIsafe telegrams exchanged between the safety PLC and F-devices.
• Configuration mismatch between the safety PLC's project and a connected PROFIsafe F-device (e.g., incorrect F_iPar_CRC, wrong device type, or incompatible firmware version).
• Internal PROFIsafe driver or protocol stack corruption within the safety PLC's firmware, preventing proper communication processing.
• Loss of cyclic PROFIsafe communication packets due to network instability (e.g., physical cable break at an RJ45 connector, faulty switch port, excessive network load).

Click steps to track your progress.

1. 1

   Review the PROFIsafe configuration in the engineering software, verifying that the F_Address and F_iPar_CRC for all connected F-devices match the PLC's project.

2. 2

   Check the diagnostic buffer of the safety PLC and all connected PROFIsafe F-devices for specific communication errors (e.g., F-device timeout, CRC mismatch).

3. 3

   Physically inspect the PROFINET/PROFIBUS cable connections to the safety PLC and all F-devices for damage, proper termination, and secure seating of connectors (e.g., RJ45, M12).

4. 4

   Using a network diagnostic tool (e.g., PROFINET Inspector), verify the integrity of the PROFINET network, checking for packet loss, jitter, or overall communication load.

5. 5

   Perform a consistent download of the entire safety project (hardware configuration and safety program) to the safety PLC and all connected F-devices.

6. 6

   If the issue persists, test by temporarily disconnecting one F-device at a time to isolate a potentially faulty device or replace the safety PLC module.