The Siemens 3RK3242-2AA10 is a SIRIUS modular safety system expansion module delivering four fail-safe digital outputs (4 F-DO). It operates on a 24 V DC control supply and is designed for integration into safety circuits rated up to Performance Level e (ISO 13849-1) and SIL 3 (IEC 61508, IEC 62061).
What the safety ratings mean for your circuit
PL e and Category 4 (EN 954-1, EN ISO 13849-1) mean this module is designed for the highest level of fault tolerance in safety-related control systems — it can tolerate a single fault in any component without losing the safety function, and a second fault is detected before the next demand. SIL 3 per IEC 61508 and IEC 62061 confirms the same integrity for machinery safety functions: the probability of dangerous failure per hour is below 10⁻⁷. That puts it squarely in the range for guarding applications like press brakes, robotic cells, and conveyor hazard zones where a failure could cause serious injury. The four fail-safe outputs are parameterizable, so you can configure the output behavior (e.g., pulsed test signals) to match the downstream contactors or valves without adding external relays.
Vibration resistance is tested to 0.75 mm at 5–500 Hz per IEC 60068-2-6, and shock resistance is rated at 15 g for 11 ms, so it holds up in environments with moderate mechanical stress (e.g., near conveyors or presses).