White Paper: Safety Integrated Functions in Servo Drives

In 1998, the IEC 61508 standard for Functional Safety was released for electrical systems. This provided standardization of safety concepts and laid the groundwork for further technological advancements in safety.   Over time, servo drive manufacturers began implementing these changes, leading to the development of additional functions, including core functions (STO) in the 2000s and safe stop and speed functions (SS1, SS2, SOS, SLS, SLP, SDI) in the 2010s.   Also at this time, networked safety solutions and programming were being developed and implemented. Fieldbus solutions such as Functional Safety over EtherCAT (FsOE), PROFIsafe, and CIP Safety were created to enable these safety functions to be easily programmed.   This white paper examines the progress of this technology, covering basic and advanced safety functions and network safety options commonly used with today’s servo drives to make machines safer to operate and easier to maintain.