Code

Name

Causes

Possible Solutions

STo

Safe Torque OFF

Safe Disable inputs H1-HC and H2-HC are open.

  • Make sure that the Safe Disable signal is input from an external source to terminal H1-HC and H2-HC.

  • When the Safe Disable function is not in use, use a jumper to connect terminals H1-HC and H2-HC.

There is internal damage to the two Safe Disable channels.

Replace the board or the drive. Contact Yaskawa or your nearest sales representative to replace the board.
Note:

  • The drive will not output an alarm signal for this alarm.

  • If the drive detects this error, the terminal set to H2-01 to H2-04 = 21 [MFDO Function Select = Safe Torque OFF] will activate.