Sto - Safe Torque Off And Sbc - Safe Brake Control; Introduction To The Sto And Sbc Functions - Danfoss Vacon OPTEA Operating Manual

VACON® NXP Advanced Safety Options
Operating Guide
3. The SS1 function
4. The SS2 function
When a higher priority function is requested while a lower priority function is active, it interrupts the lower priority function and
becomes active. The higher priority function behaves as it is parameterized. The lower priority function stays active, but it stops
monitoring.
When a lower priority function is requested while a higher priority function is active, the lower priority function does not become
active.
Speed
Speed
Zero speed
SS2 td1
Logical level
SS2 Active
SS1 Active
SS2 Reached
SS1 Reached
Illustration 28: The SS1 Function Interrupts the SS2 Function. The Signal SS2 Active Stays Active but the Operation Stops
If a higher priority function interrupts a lower priority function, both functions must be not requested for the STO(+SBC) or the SOS
function to be deactivated.
If the SS1 function is requested when the SOS function is active (if, for example, the SS2 function is reached), the SS1 function acti-
vates the STO function after SS1 td2, without ramp or time monitoring.

6.2.2 STO - Safe Torque Off and SBC - Safe Brake Control

6.2.2.1 Introduction to the STO and SBC Functions

The Safe Torque Off (STO) safety function allows the drive output to be disabled so that the drive cannot generate torque to the
motor shaft.
Danfoss A/S © 2021.06
SS1 td1
Safety Functions
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