ASIsafe safety monitor for safe AS-i outputs
The Siemens 3RK1105-1BG04-4CA0 is an ASIsafe extended Safety monitor with two fail-safe relay outputs (F-RO) and an integrated safe AS-i slave. It provides two enabling circuits and is designed to control safe AS-i outputs in a safety loop. Rated for use up to Category 4 per EN 954-1, Performance Level e per EN ISO 13849-1, and SIL 3 per IEC 61508, this monitor suits guarding applications where a 40 ms maximum response time is acceptable for the safety function. The unit carries a 24 V control supply drawing 1 A, and its relay outputs are rated 3 A at DC-12 (24 V) and 3 A at AC-12 (250 V). The AC-12 rating covers resistive loads; the DC-12 rating covers resistive and slightly inductive DC loads.
Mounting and wiring in the panel
The 45 mm width takes one standard modular unit, and the 120 mm depth fits shallow enclosures. IP20 protection means it belongs inside a cabinet, not on the machine frame. All I/O connections use spring-loaded terminals — strip 8 mm, no screwdriver needed for the power or signal wiring. Removable terminal blocks simplify pre-wiring the panel before inserting the monitor.
AS-Interface integration
Supports the AS-Interface protocol natively, with the integrated safe slave communicating safety data over the same yellow flat cable as the standard AS-i slaves. No separate safety bus wiring is needed. The reference code per EN 61346-2 is F, classifying it as a protective device in the system schematic.