The Siemens 3RK1205-0BQ30-0AA3 is an ASIsafe K20F compact module that brings two safe digital inputs (F-IN1 and F-IN2) into the field, designed specifically for mechanical switching contacts like emergency-stop pushbuttons or limit switches. Each input is dual-channel (PIN 1/2 for F-IN1, PIN 3/4 for F-IN2), so a single sensor pair occupies one M12 socket. The module draws up to 45 mA from the AS-Interface bus (26.5... 31.6 V per the AS-i spec), and the built-in polarity reversal protection saves a blown fuse on a miswired cable. IP67 means the housing and M12 connectors handle washdown — mount it right on the machine frame, no enclosure needed.
Deployment context — where this module lives
This is a field-deployed safety I/O slice for AS-Interface Safety at Work (ASIsafe). It sits on the machine, not in a cabinet — the IP67 rating and M12 screw-type terminals let it live next to actuators and sensors on a conveyor or packaging line. No mounting plate is required; the 20 mm wide body fastens directly to the machine frame or a sub-panel. The yellow LED per input gives a quick visual on channel state, and the green/red dual LED on the AS-i diagnostics shows bus health and communication faults.