Siemens 3RK3231-1AA10 Programmable Logic Controller Module

Siemens 3RK3231-1AA10 MSS EXP Module is a 24 V DC expansion module for the SIRIUS modular safety system 3RK3 that adds additional fail-safe IO to a central MSS unit. It provides 2 or 4 fail-safe digital inputs (F-DI) and 2 fail-safe digital outputs (F-DO), and is parameterizable via MSS ES for flexible safety circuit configuration. The module is 22.5 mm wide with screw-terminal connections, designed to extend safety-related input and output capacity in a 3RK3 installation. It supports up to SIL 3 (IEC 61508) and up to Performance Level e (ISO 13849-1) in appropriate system configurations, making it suitable for safety tasks such as interfacing safety sensors and actuators, interlocks, and safety-related signaling within a SIRIUS MSS setup.