The Siemens 3RK1205-0CQ00-0AA3 is an ASIsafe compact module from the K45F family — four safety-rated digital inputs for mechanical switching contacts, packaged in a 45 mm wide IP67 housing with M12 connectors. It sits directly on a machine frame or conveyor section, not inside a control cabinet; the IP67 rating means the module and its M12 sockets survive washdown environments on food, beverage, or automotive lines. Power and safety data travel over the AS-Interface flat cable, so no separate control wiring is needed back to the panel.
The four safety inputs (4 F-DI) accept mechanical switching contacts — standard limit switches or safety gate switches with dry contacts. Each input draws a minimum of 5 mA at signal <1> to register a closed contact, which is typical for AS-Interface safety slaves and ensures reliable detection even with long cable runs. The module is addressed via the front addressing socket, and the ID/ID2 code is set to B/F. The yellow LEDs on each input give immediate visual feedback during commissioning or fault-finding. Operating voltage follows the AS-Interface specification at 26.5 to 31.5 V DC, and the module draws up to 70 mA from the AS-Interface bus — that total includes the electronics and the input sensing current, so it fits within a standard AS-Interface power supply budget even on a heavily populated segment.
The 45 mm width and 34 mm depth keep the footprint compact for tight spots on a machine frame. All four M12 input sockets are on the front face, and the AS-Interface connection is via the standard piercing technique through the flat cable. No backplane or separate bus coupler is needed — the module is a fully addressable AS-Interface slave.