The ABB 2TLA010040R0000 — “SENTRY BSR10” — is a compact safety relay / expansion relay designed for industrial safety circuits. It can monitor a simple safety input (e.g. an emergency‑stop button) and provide safety‑rated output contacts, or be used as an expansion relay to increase the number of safe outputs when connected to a main safety relay or safety controller. Supplied by 24 V DC, it supports direct wiring of safety devices in the relay power supply circuit. The relay is DIN‑rail mountable, uses screw‑terminal connections, and is suitable for emergency‑stop circuits, simple machine safety controls, or as output expander in larger safety systems.
