ASIsafe module for two-channel safety on AS-Interface
The Siemens 3RK1205-0BG00-0AA2 is an ASIsafe Safe SlimLine module S22.5F carrying two fail-safe digital inputs (2 F-DI) rated for mechanical switching contacts — think emergency-stop pushbuttons, door interlock switches, or position limit switches wired into an AS-Interface safety network. Each input reads a dry contact: open is the low signal level, closed is the high signal level. The module communicates over the AS-Interface bus protocol, drawing up to 45 mA from the bus supply (26.5–31.5 VDC per the AS-Interface specification). The front panel carries a yellow LED per input for I/O status and a green/red LED for AS-Interface diagnostics and communication health. Addressing is set via a front addressing socket using the standard AS-Interface addressing tool.
Lifecycle status — phased out, sourced to order
This part is marked as a phased-out product. The manufacturer's description explicitly states "Phased-out product!!!" and directs inquiries to the sales department for further information on the digital safety portfolio.
At 22.5 mm wide and 91 mm deep, this module occupies a single modular-width slot on a DIN rail — useful when panel space is tight and you need to squeeze a safety input node between standard 22.5 mm I/O blocks. IP20 means it belongs inside an enclosure, not on the machine frame.
The two fail-safe digital inputs are designed for mechanical switching contacts — that is, standard E-stops, safety gate switches, and interlock contacts that provide a dry open/closed signal. The module does not supply sensor power; it reads the contact state from the AS-Interface bus power. The switching levels are defined as "contact open" (low) and "contact closed" (high), with a minimum input current of 5 mA at the high signal. This current is sufficient to wet the contacts and prevent oxide buildup on low-voltage dry contacts — a common failure mode on safety circuits that see infrequent actuation.