USS setpoint fault

What does F00071 mean?

The drive has failed to receive setpoint values via the USS (Universal Serial Interface) communication protocol within the configured telegram off time. This suggests a problem with the USS master device or the communication settings, causing the drive to lose its operational commands and halt controlled operation.

• RS485 communication wiring error (e.g., A/B lines swapped, common ground missing on terminal 9 (X101), loose terminals).
• Incorrect USS communication parameters (e.g., P2010 Baud rate, P2011 Address, P2013 Telegram off time) on either the USS master or the drive.
• The USS master device is not sending telegrams or is experiencing an internal fault preventing setpoint transmission.
• Excessive electrical noise on the RS485 bus due to unshielded cables or improper grounding, causing data corruption.
• Terminating resistors (e.g., 120 Ohm) are missing or incorrectly placed on the USS bus (e.g., P2015 bit 0 not set for internal termination).

Click steps to track your progress.

1. 1

   1. Verify the wiring of the USS (RS485) bus on terminals X101, ensuring A/B lines are not swapped and the common ground is securely connected.

2. 2

   2. Check USS communication parameters P2010 (Baud rate), P2011 (USS address), and P2013 (Telegram off time) on the drive to precisely match the USS master device.

3. 3

   3. Monitor the USS communication status (e.g., P2017) on the drive or use a USS sniffer tool to analyze telegram traffic from the master.

4. 4

   4. Temporarily increase P2013 (USS telegram off time) to 500ms and retest communication from the master device.

5. 5

   5. Ensure RS485 terminating resistors (typically 120 Ohms) are correctly applied at both ends of the USS bus (e.g., activate P2015 bit 0 for internal termination on the drive).