The Protect SPP0015 Smoke Cannon Unibuscard is an essential component for operating certain Protect smoke cannon models. It most likely functions as a communication interface card between the smoke cannon unit and the security system's control panel. This card facilitates commands and data exchange, enabling the control panel to trigger smoke deployment from the smoke cannon. The Unibuscard design suggests compatibility with a specific communication protocol used by Protect security systems. Without more details, it's difficult to pinpoint the exact functionality.