With safe stop 2 (SS2), the defined motor braking is part of the safety function. When the motor is at standstill, a safe operating stop (SOS) is triggered. Unlike safe stop 1 (SS1), the motor at standstill is in closed loop operation.
This means that the standstill position is held precisely, due to the active control loop. Again, there are several options for implementing these requirements. This safety function corresponds to a category 2 stop (controlled stop) in accordance with IEC 60204-1.
If the axes no longer need to be shut down at standstill, they will actively hold their current position and consequently the synchronisation between axes and process is no longer lost. As a result, the axes can be restarted immediately at any time, which clearly increases plant availability. Here too, the drive-integrated function leads to shorter reaction times, thereby minimising the risks. The monitoring functions’ response times have a direct influence on the potential channels available until a safety shutdown occurs.
More information on safe motion monitoring can be found on our application page: