Industrial automation requires top safety standards, and the TWX Motor Series with Integrated Drive meets SIL 2 and SIL 3 certifications.
Featuring the Safe Torque Off (STO) safety function, TWX ensures enhanced operator protection and machine safety by instantly cutting off motor torque power when necessary, preventing unexpected startups during maintenance or human presence.
Unlike conventional switches, STO is a fieldbus-independent, redundant safety system that simplifies design, reduces costs, and maintains critical machine functions. With SIL 3 certification, TWX also provides feedback signals to verify that the safety response is executed correctly, ensuring maximum reliability in industrial environments.
The TWX Motor Series with Integrated Drive, is compliant with the Safety Indistrial Level (SIL) 2 and 3.
Safe Torque Off is an important safety function integrated into TWX servo drive: it cuts off eMotor torque power to prevent unexpected start up, such as during maintenance or human presence.
It is controlled by two dedicated wires inside the power cord that carries a low voltage +24 V signal to the drive.
When at least one of the two signal are interrupted, tipically by operator pressing the safety button, STO is activated.
In this way, STO function is a fieldbus indipendent and redundant safety system(single fault tollerance).
It is safer then a simple switch or disconnectors, reducing as well the total complexity, costs and space.
The main power can be kept so to mantain other safety and general machine functions.
STO activation generates a Drive Fault that has to be reset to restore normal condition, and a Canbus Alarm packet informs all other machines, master, or systems.
STO with SIL 3 level allow a feedback signal so to ensure that the safety response is correct
STO is not an emergency brake: after power cutoff to motor, it could still rotate as a result of system inertia and can be dangerous in case of suspended loads.
STO doesn’t actually shut down the source main power: if needed it has to be shutdown manually
As an additional safety feature, the TWX motor enables the use of the Auxiliary Input inside the power cord (refer to the pinout scheme) to trigger a quick stop or power disable action via firmware. Users can select whether the action occurs on a high or low Aux signal state. To configure this behavior, access the digital input section of CockpitLT. By default, the Aux input remains inactive until the user sets a specific function.
