ASIsafe Safety Monitor – 2 Enabling Circuits, SIL 3
The Siemens 3RK1105-1BE04-1CA0 is an ASIsafe Basis safety monitor with 2 enabling circuits — a special-version safety relay module designed to supervise safety functions on an AS-Interface network. It is rated for use up to Category 4 (EN 954-1), Performance Level e (EN ISO 13849-1), and SIL 3 (IEC 61508), so it can serve as the safety logic element in guarding applications up to the highest standard industrial safety integrity levels. The 50 ms maximum response time means the monitor reacts within one mains cycle, fast enough to stop a hazardous motion before a hand enters the danger zone. Control supply draw is 1 A at 24 V, with lower consumption at higher voltages: 0.1 A at 115 V and 0.05 A at 230 V. The safe output relays are rated for 3 A at 24 V DC (DC-12/DC-1) and 3 A at 250 V AC (AC-12, 50/60 Hz) — these are resistive-load ratings, so derate for inductive or lamp loads. The module has 2 release circuits and 2 enabling circuits, meaning it can independently switch two safety paths, which is useful for dual-channel monitoring of e-stops or light curtains.
All I/O connections are via screw terminals with removable terminal blocks, so the wiring base stays in the panel while the module is swapped. AS-Interface protocol is supported natively, so this monitor communicates directly on the AS-i bus without an extra gateway module. The reference code per EN 61346-2 is F, which classifies it as a protective device in the function-oriented labelling scheme.