K-bus Input Update Not Complete (TwinCAT)

What does State Variable Bit 9 mean?

The K-bus State variable in TwinCAT has Bit 9 set, indicating that the K-bus input update cycle has not yet completed within the expected time. This can lead to outdated or missing input data in the PLC program.

• K-bus input data update cycle not completed within the expected time.
• Interruption in the input data acquisition process.
• Slow response from input devices.
• TwinCAT task scheduling issue affecting input updates.

Click steps to track your progress.

1. 1

   Evaluate the TwinCAT task time configured for the K-bus. Ensure the task time is sufficiently fast (recommended less than 50 ms) to allow for complete input updates.

2. 2

   Check for high system loading or excessive data traffic on the K-bus that might be delaying the completion of input update cycles.