Siemens S54370-B1-A1 XTRI-R Intel Interface Card

The Siemens XTRI-R S54370-B1-A1 is an intelligent, addressable single-input interface module with a built‑in Form-C relay and isolator for Siemens modular fire safety and building‑automation systems. It monitors a dry contact (normally open or normally closed) on its input and exposes a relay output at the same address, enabling control or shunting of external equipment without a separate controller. Marketed as XTRI-R — Single Input Module with Relay, the S54370-B1-A1 variant includes a relay‑status LED (two blinks indicate a relay state change) and carries safety and fire‑safety listings including UL864, UL2572, UL2017, and CAN/ULC‑S527 and CAN/ULC‑S576. As part of Siemens' XTRI family of intelligent devices, this module enables direct interface of switches and devices to the device loop, reducing wiring complexity while maintaining tight integration with Siemens control panels.