Functional Safety

Safer machines with integrated safety

What is functional safety?

Functional Safety entails the detection of a potentially dangerous condition resulting in the activation of a protective or corrective device or mechanism to prevent hazardous events arising or providing mitigation to reduce the consequence of the hazardous event.

In the design of a machine, a risk assessment must be performed and then updated regularly. As far as possible, the machine should be designed to be inherently safe, so that hazards are eliminated from the basic design. However, in most cases some risks remain at an unacceptable level and must be actively reduced using suitable control measures.

Why integrated safety?

The integration of motion safety functions in the drive supports a decentralized approach to the machine's functional safety that brings many benefits

Reduced complexity and therefore design time
Reduced wiring and consequential costs
Ease of commissioning
Speed of actuation due to close-coupling of safety function and drive

Functional-Safety-Conventional-Integrated-Approach-Diagrams

Benefits

	Simple, cost-effective & functional
The conventional approach to functional safety relies on an external safety controller, electromechanical components to disconnect the drive from the motor and often additional sensors to monitor speed or position. Integrated safety can dramatically reduce the cost and design time. Onboard STO safely switches off torque to the motor negating the need for external contactors. The addition of an MiS210 or MiS250 Safety option enables complex safe motion monitoring directly on the drive using the existing motor encoder. While many applications can be completely solved with a drive-based distributed architecture, when an external safety PLC is required, drive integration is easily achieved using network safety protocols.
	Performance without compromises
When protecting people and equipment from hazards, timeliness is of the essence. Integrated safety offers faster reaction times, thanks to the close-coupling of safety function and drive. Support of the SafeEnDat protocol enables the use of functional safety certified encoders, with the ability to reach SIL 3 / PLe with a single motor-mounted encoder. All of our integrated safety functions are externally certified to control category SIL 3 or PLe (Performance Level e).
	Flexible safety solution
With an integrated safety solution from Control Techniques you always enjoy maximum flexibility, be it in the functional design or the choice of components and protocols to integrate. The MiS210 and MiS250 options support several encoder protocols on up to 4 different channels wired to the drive or directly to the module. Onboard Motion Safety Functions support multiple instances and safe logicblocks are also available to allow implementation of complex safety chains. Control and monitoring of the functions, as well as transfer of safe position and speed values are available over the main safety fieldbuses: CIP Safety over EtherNet/IP and FSoE over EtherCAT