The Siemens 3SF5811-0AA10 is a complete AS-Interface emergency-stop pushbutton assembly — one part number, one box. It ships as a single unit: the red mushroom actuator (plastic, 22 mm mounting diameter) on a yellow plastic enclosure, with the AS-i slave (F slave, 2I) integrated. No separate base, no loose electronics to wire in. The kit is complete: the rotate-to-unlatch mechanism, the positive-opening NC contacts (two switching elements), and the IP65 seal are all factory-assembled. What you don't get: a light source (no lampholders, no optional light extension), a front ring, or a protective collar — this is a pure E-stop, not an illuminated pushbutton.
AS-Interface integration — what the F slave, 2I means on the line
This is an AS-Interface safety slave — specifically an F slave with 2 inputs. It occupies one AS-i slave address on the bus. The F slave designation means it communicates safety-related signals (the E-stop's NC contacts) over the AS-i safety protocol, so it can be wired directly into a safety-monitored AS-i network without a separate safety relay. The 2 inputs correspond to the two switching elements inside the E-stop, giving you dual-channel monitoring for redundancy. The slave is designed for floor mounting (vertical fastening), and the square yellow enclosure carries the black E-stop label. The 30 V DC operating voltage is standard AS-i bus power — no separate supply needed.
Mounting and panel fit — the 22 mm hole, the 64 mm depth
The actuator requires a standard 22 mm round mounting hole — common across industrial E-stop and pushbutton panels. The enclosure footprint is 85 mm wide by 85 mm high, with a depth of 64 mm behind the panel. That 64 mm depth is the key clearance number: it means the AS-i electronics and wiring space fit inside a standard 80 mm deep enclosure or junction box. The plastic housing is rated IP65, so it handles washdown and dust ingress in food, beverage, or general wet-area lines. The rotate-to-unlatch mechanism means the operator twists the red mushroom head to reset — no key required.