AS-Interface emergency stop station in a 22 mm round enclosure
The Siemens 3SF5811-0AE08 is a complete AS-Interface emergency stop station built into a 22 mm round plastic enclosure with a yellow top and protective collar. It carries a 40 mm red mushroom pushbutton that rotates to unlatch, secured with a RONIS SB30 lock. The switching element provides two normally-closed contacts (1 NC + 1 NC), wired via an insulation displacement connection on top of the enclosure. This is the part you reach for when a line-side E-stop needs AS-i bus integration without a separate I/O module — the bus connection and the safety contact block live in one housing.
The 22 mm round form factor is the standard panel cutout for pilot devices — it drops into any enclosure that accepts 22 mm pushbuttons or selector switches. The insulation displacement termination on top means you land the AS-Interface flat cable without stripping or screw terminals; the cable runs through the enclosure top and the contacts pierce the insulation. The RONIS SB30 lock prevents the E-stop from being reset without a deliberate rotation, which satisfies the anti-tamper requirement in IEC 60947-5-5 for emergency stop devices. Two NC contacts give you one channel for the safety circuit and one for the AS-i status feedback, or both in series for a redundant safety path.
Deployment context
This enclosure mounts to a panel or machine frame via the standard 22 mm cutout, common on control stations, conveyor line pedestals, and packaging machine operator panels. The yellow top with protective collar is the standard safety color per ISO 13850 — it signals emergency stop function at a glance. The AS-Interface bus connection means it integrates directly into a Siemens AS-i network without a separate gateway or I/O block for the E-stop.