The Siemens – Fire Safety Intelligent Interface Module (Model XTRI-M) is designed to provide the means of interfacing direct shorting devices to the fire-alarm control panel (FACP) loop circuit. The module uses one (1) address on the loop. Each XTRI-series interface module provides the “built-in” ISOtechnology feature – intelligent dual isolation meeting NFPA 72 Class X (Style 7) wiring requirements. Up to 252 isolation ready devices per loop and in mixed mode a maximum of 30 non-isolated devices between isolated devices (wired in polarity-insensitive mode). Additionally, the devices between isolators can either be ‘H’-series or the more contemporary ‘X’-series detection devices.