The Vectra's default is Constant mode which is ideal for most applications. That said, the Vectra line is capable of being run in Gyre, ReefCrest, and Lagoon mode. Keep in mind, this is only for Vectras installed in a closed-loop application and has been calibrated.
It's important to remember, the Closed Loop mode is not advisable for Vectras used as a return pump. Varying the speed of your return pump can cause water level fluctuations in your aquarium and sump which may lead to overflows.