The motor speed can be regulated manually with the potentiometer on the front of the unit, or using other control options like the unit’s keyboard, an external potentiometer, an analogue voltage or current signal, preset frequencies actuated by digital inputs, the RS485 port, or automatic PID control. The latter option is a closed loop control system widely used for controlling pumps and fans, in which the drive automatically regulates the speed of the motor to hold a given physical value constant (for instance pressure, temperature or flow rate).
There is also an Autorun (sequencer) function, which allows the user to program a sequence of frequency/time cycles composed of customised frequency, motor direction and step duration presets.

As for the hardware, an integrated category C2 EMC filter (EN61800-3) reduces electromagnetic disturbances. A remote keyboard (VT1X C02) can be installed to the front of the enclosure for programming and controlling the unit externally.

The new VT1 variable speed drives are available in the following power ratings: 0.2, 0.4, 0.75, 1.5 and 2.2 kW.