# Safe Torque Off > Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Safe_Torque_Off > Markdown URL: https://mediated.wiki/source/Safe_Torque_Off.md > Source: https://en.wikipedia.org/wiki/Safe_Torque_Off > Source revision: 1302752768 > License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/) The '''Safe Torque Off (STO)''' is an electronic signal used in industrial [motor controller](/source/motor_controller)s for safety reasons. ==Description== The STO function is the most common and basic drive-integrated safety function. It ensures that no torque-generating energy can continue to act upon a motor and prevents unintentional starting.{{cite web|title=STO Definition by Siemens|url=http://www.industry.siemens.com/topics/global/en/safety-integrated/machine-safety/product-portfolio/drive-technology/safety-functions/pages/safe-torque-off.aspx|accessdate=29 June 2016|archive-date=3 August 2017|archive-url=https://web.archive.org/web/20170803015225/http://www.industry.siemens.com/topics/global/en/safety-integrated/machine-safety/product-portfolio/drive-technology/safety-functions/pages/safe-torque-off.aspx|url-status=dead}} ==External links== * [http://new.abb.com/drives/functional-safety/typical-safety-functions ABB Webpage Tutorial] * [http://www.industry.siemens.com/topics/global/en/safety-integrated/machine-safety/product-portfolio/drive-technology/safety-functions/pages/safe-torque-off.aspx Siemens Webpage Tutorial] {{Webarchive|url=https://web.archive.org/web/20170803015225/http://www.industry.siemens.com/topics/global/en/safety-integrated/machine-safety/product-portfolio/drive-technology/safety-functions/pages/safe-torque-off.aspx |date=2017-08-03 }} ==References== {{Reflist}} Category:Electrical safety Category:Electric motors --- Adapted from the Wikipedia article [Safe Torque Off](https://en.wikipedia.org/wiki/Safe_Torque_Off) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Safe_Torque_Off?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.