Torque is safely removed from the motor. Motor stops by Inertia (or Dynamic Brake). It is the ultimate safest function. When other safety functions fail the drive executes STO.

• STO function can be executed by hard wire or Safety over EtherCAT. 
• Commonly used for most axes and usually linked to E-Stop switches

Timed STO. The torque in the motor is removed at a certain (settable) time after SS1 activation, so the controller has time to stop the load in a controlled manner before the STO is executed.

• SS1 function can only be executed through Safety over EtherCAT.
• Commonly used when you need STO in machines with Highly Inertial loads that will take too long to stop by friction. 
• Up to 8 instances of SS1 (with different delay each) can be set.

Motor stays standstill in the stop position. Torque in the shaft is allowed.

• Commonly used with Machines that needs to be manipulated with axis in a certain position.  Eg: changing printing roll in machine for “flexible packaging printing” 
• Up to 8 instances of SOS (with different settings each) can be set
• For SOS standard safety function blocks can be used

Timed SOS. SOS is activated after some delay.

• Used for Similar applications than for SOS but SS2 must be used if the execution of the safety function is not known in advanced (a “request access” is not present) so the stop sequence must be executed after the safety function is requested.
• Up to 8 instances of SS2 (with different settings each) can be set.
• Note: Instance 1 of SS2 is related to Instance 1 of SOS and so on.

Drive monitors that a certain maximum speed is not exceeded. By far, the most used and requested Motion Safety Function.

• Commonly used for Any kind of Axis/machine where you need to access to the moving parts but you do not want to stop the machine (because start-up is time consuming or simply because you want to maximize the production).
• We have 8 instances of this function with different settings.

Drive guarantees that the movement occurs only in one direction (rotation). 

• Commonly used for axes that can trap your hands in case they rotate or move in the “wrong” direction, like winders or cutters, or when the mechanics can be destroyed if moved in the wrong direction
• Only one instance of this function.
• This function can be requested separately for positive direction or for negative direction
• If you activate Safe Direction Positive and Negative at the same time, the result is equivalent to SOS.

Drive monitors that actual position is inside “safe” limits. 

• It is necessary first to safely link the motor-encoder position with the load via “safe origin”. Drive has dedicated Inputs for this.
• Commonly used for axes with different working area so the movement goes far from the operator when he enter in the machine.
• We have 8 instances of this function with different settings.
• Link between mechanical position and motor encoder requires to pass through the corresponding sensors.

Drive can activate and monitor the status of an external Safe Brake. Drive has dedicated IO’s for this functionality. This function is usually linked to STO function.

• Note: motor brake is “holding brake”, not safe.
• Commonly used for vertical loads under which operators or maintenance people can be present. Stacker crane, palletizers, etc.
• We have only one instance of this function (only one brake is expected per one motor).
• This function can be executed as a separated function or in combination with STO or SS1