The sensorless rotation direction monitoring modules DN3PR1 don´t require a measuring system either and are unique on the market in this way.
For safe monitoring of 1- to 3-phase motors up to 690V AC with performance level e, it is not even necessary to parameterize the device.
The module measures the frequency of the 3 motor phases as long as the drive is running. The output provides a signal when the drive moves in the preset desired direction. However, the contact output opens immediately should the drive move in a different, wrong direction, which interrupts the circuit and stops the drive.