Cause : Safe Disable Signal Input comes when one Safe Disable channel is open while the other channel is closed. The signals to the Safe Disable inputs are wrong or the wiring is incorrect. 

1. Check signal status at the input terminals H1 and H2. If the Safe Disable function is not utilized, terminals H1-HC, and H2-HC must be linked.
2. One of the Safe Disable channels is faulty. Replace either the control board or the entire drive.