Powershield Internal Relay Comms Card with Terminal Connector The Relay Card (PSAS400) provides VFC (Volt Free Contact) relays that change state upon UPS events. This type of card is often used when current loop communications are required for devices such as BMS (Building Management Systems), Access Control Alarm Panels or Industrial PLCs. User selectable normally open (default) or normally closed contacts. PRODUCT FEATURES Volt Free Contact Provides contact closures for remote monitoring of your UPS Capable of selecting the status of the dry-contact signal