The Siemens 3RK1405-1BQ00-0AA3 is an ASIsafe compact module from the K60F family, designed to bring two safety-related digital inputs and two standard solid-state outputs onto an AS-Interface network. It reads mechanical switching contacts — think emergency stops, guard door switches, or interlock sensors — and reports their status over the AS-i bus, while the two outputs switch 24 V DC loads at up to 2 A each.
Safety inputs are two channels, each drawing a minimum of 5 mA at signal high, designed for dry-contact sensors. The outputs are solid-state, short-circuit proof, and rated 2 A per channel at 24 V DC — enough for small solenoid valves, signal lamps, or contactor coils. The module draws up to 270 mA from the AS-Interface bus for its own electronics; the output power comes from a separate 24 V DC auxiliary supply via the AUX POWER pins.
The module snaps onto standard DIN rail or mounts to a wall using the 3RK1901-0CA00 mounting plate (ordered separately). All I/O connections are via four M12 sockets; pin assignments follow a special scheme for the safety inputs and a standard scheme for the outputs. The ground terminal on pin 5 of each M12 socket ties to the mounting plate's grounding wrist strap, which is critical for maintaining the safety earth path in a machine-mounted installation.
On-board diagnostics and addressing
Each input and output has a yellow LED for status indication. The auxiliary supply has a green LED; the AS-Interface communication and diagnostics share a green/red LED. Addressing is done through a front-facing socket, and the module carries an ID/ID2 code of B/F. A built-in watchdog monitors the AS-i communication and the safety logic, and built-in short-circuit and induction protection cover the outputs.