No Valid Inputs (TwinCAT)

What does State Variable Bit 8 mean?

The K-bus State variable in TwinCAT has Bit 8 set, indicating that there are currently no valid inputs being received from the K-bus. This can happen if input terminals are disconnected, faulty, or if there's a broader communication issue.

• No valid input data received from the K-bus terminals.
• All input channels are disconnected or in an invalid state.
• Input data not updated by the connected devices.
• Configuration error preventing valid input acquisition.

Click steps to track your progress.

1. 1

   Verify the physical wiring and operational status of all input-only Bus Terminals. Check for disconnected sensors or faulty terminal units.

2. 2

   Check for general K-bus communication errors, which might be preventing any input data from being read (refer to page 80 for K-bus ERR LED diagnostics).