What this part is and where it fits
The Siemens 3SF5900-2CC is a connection element for AS-i (Actuator-Sensor Interface) networks, designed to link an AS-i enclosure to the M12 trunk cable. It accepts one to three control points and terminates at an M20 gland. The metal housing carries an IP67 rating, so the assembly withstands washdown and wet-area exposure — common on conveyor lines, packaging machines, and food-grade production cells where a sealed fieldbus drop is required. Fastening is direct mounting — no DIN rail clip, no snap-on foot. The part bolts or screws flat to a panel or enclosure surface. That means the panel builder needs to plan a dedicated mounting hole pattern; it does not share the standard 35 mm DIN rail with contactors or power supplies.
Environmental limits and compliance
The substance prohibitance date of 07/01/2006 aligns with the original EU RoHS directive (2002/95/EC). No later RoHS recast or REACH SVHC declaration is explicitly listed in the spec table, so the compliance documentation that ships with the part should be verified against your local regulatory requirements at order time.
Connection and wiring detail
The auxiliary and control circuit connection is via a connector — not screw terminals or spring clamps. The M12 round connector is the AS-i standard pinout; the M20 cable gland on the opposite side accepts the field cable. The reference code per IEC 81346-2 is X, which designates a terminal or connection point in the system schematic.