Frequency inverter with Safety PLe

The project objective was to develop and manufacture a frequency inverter-based machine control system. In order to enable use in machines that pose a danger to people, the core requirement was to achieve safety level PL e. As soon as a danger zone guard, such as a light barrier, is interrupted, the motor control must be stopped. In this case, the objective was for the motor to turn in the opposite direction, for example to free a trapped person. Two CPUs and a special algorithm, combined with monitoring methods, meet these requirements and enable the highest level of safety to be achieved! For worldwide use, there are assembly variants for the 230V or 110V voltage network. Tolerances also cover use in other networks, such as Japan (100V). Buttons, light barriers and temperature sensors can be connected directly to the circuit board and evaluated. The machine controller communicates with an external HMI for extended operation. The connection option to an edge controller and the Knestel cloud platform is forward-looking.