Ss2 - Safe Stop 2 And Sos - Safe Operating Stop; Introduction To The Ss2 And Sos Functions - Danfoss Vacon OPTEA Operating Manual

VACON® NXP Advanced Safety Options
Operating Guide
Logical level
SS1 Request
Speed
Zero Speed
Logical level
SS1 Active
SS1 Reached
STO Reached
Reset
Illustration 40: The SS1 Signals in Zero Speed Monitoring Mode in a Violation Case. The STO Function without SBC.

6.2.4 SS2 - Safe Stop 2 and SOS - Safe Operating Stop

6.2.4.1 Introduction to the SS2 and SOS Functions

The Safe Stop 2 (SS2) safety function starts the motor deceleration and activates the SOS function.
The SS2 function can operate in one of the three monitoring modes:
• Time monitoring mode
• Time + zero speed monitoring mode
• Time + zero speed + ramp monitoring mode
The SS2 function can activate the SOS function:
• When an application-specific time delay has passed (Time monitoring)
• When the speed reaches zero speed (Zero speed monitoring)
The violation response of the SS2 function is the STO(+SBC) function. During ramp down, it is possible to monitor the deceleration.
If there is a violation in the ramp monitoring of the SS2 function, or if zero speed is not reached, it activates the STO(+SBC) function
as a violation response.
The SOS safety function keeps the drive output active and monitors the positions of the motor shaft. A violation of the position
monitoring of the SOS function activates the STO(+SBC) function.
The SS2 and SOS functions fulfill the stop category 2 of the standard IEC-60204-1.
The parameters of the SS2 and SOS safety functions are described in
The SS2 safety function can be used only with Sin/Cos encoders.
78 | Danfoss A/S © 2021.06
SS1 t1
8.6 SS2 and SOS
N O T I C E
Violation
Parameters.
AQ319736045637en-000101 / DPD01798
Safety Functions
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