Parameter database busy

What does 90 mean?

The drive's parameter database is currently occupied because both the Local Control Panel (LCP) and the RS485 communication (e.g., Modbus) are simultaneously attempting to update parameters. This prevents concurrent modifications to maintain data integrity.

• Simultaneous write commands from both the LCP (manual input) and a Modbus master (via RS485) attempting to modify parameters.
• Continuous polling for write-enabled parameters from a Modbus master interfering with LCP navigation or save operations.
• High-frequency write requests over RS485 (e.g., setting a speed reference in Parameter 3-02) colliding with a user attempting to save a full parameter set from the LCP.
• Internal timing conflict within the drive's parameter handling logic under specific concurrent access scenarios.

Click steps to track your progress.

1. 1

   Stop all communication attempts from the RS485 master device (e.g., PLC, HMI) by pausing its write operations before using the LCP.

2. 2

   If modifying via LCP, ensure no active Modbus write commands are being sent to the drive's Holding Register 0007.

3. 3

   Increase the delay between Modbus write requests from the master device if concurrent writes are unavoidable for non-critical parameters.

4. 4

   Implement a software lockout mechanism in the Modbus master to prevent parameter writes when manual LCP access is expected.

5. 5

   Observe diagnostic registers (if available in Parameter 16-50 series) for active communication sessions to determine which interface is currently locking the database.