BECKHOFF AX5805 Installation - Manual (Page 49)

Product description
AX5805 47
3.6.5.4 Description of the SS2 safety function
Figure 27: Description of the Safe Stop 2 function (SS2) with time monitor
When the SS2 function is activated, the timer t_SS2 is started and the speed of the motor is monitored.
Similarly to the SS1 function, the SS2 function can complete in two ways. Unlike the SS1 function, when the
SS2 function completes without error, the drive will be in the SOS state (rather than the STO state).
- Completion Condition 1: If the motor is within the range of n_Zero_SS2 prior to t_SS2 timing out,
then the SOS state is activated after t_L_SS2 has elapsed.
- Completion Condition 2: If the t_SS2 timer elapses before the motor reaches the speed set by
n_Zero_SS2, then the SOS function is activated regardless of whether the motor is moving or not.
Should the parameters of the SOS function be exceeded, the SOS function will activate the STO
function, removing torque from the motor.
A corresponding instance of SOS must be used for each instance of SS2.