Description With the TROX Flow Check App is your NFC-enabled Android smartphone for on-site diagnostic tool for VAV controller and damper and the latest generation of TROX and Belimo valve actuators. Each time there! For wireless access to the parameters and operational data include these components integrated Near Field Communication, NFC recognizable by the logo: for example, VAV-Compact -Volumenstromregler with MP bus interface (2015); Butterfly Valve - PR range; ... NFC - Near Field Comm