The '''Safe Torque Off (STO)''' is an electronic signal used in industrial motor controllers 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.<ref>{{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}}</ref>
==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==
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Category:Electrical safety Category:Electric motors