The Siemens 3RK2200-0CT20-0AA3 is a K45 compact AS-Interface slave module providing 4 PNP digital inputs (Type 4 inputs) in a 45 mm wide, IP67-rated field housing. It draws power and communication from the AS-Interface bus cable — no separate 24 V supply needed beyond the bus master's power supply. The module is addressed via the front addressing socket, and the A/B slave design allows two slaves per AS-i address when the master supports it. Each input socket (4 total) uses PIN 4 for the data signal, with PIN 1 (L+) and PIN 3 (L-) carrying the sensor supply from the AS-Interface bus. The sensor supply is short-circuit and overload protected. Yellow LEDs indicate the I/O status; a green/red dual LED shows AS-Interface communication and diagnostics.
Field deployment and mounting
IP67 means the module is sealed against dust ingress and water jets — suitable for washdown zones on packaging lines, conveyor sections, or machine cells where a panel-mounted I/O block would be impractical. Mounts directly to standard DIN rail or to a wall using the optional K45 mounting plate (sold separately). The 45 mm width and 30 mm depth keep the footprint small inside a junction box or on a machine frame. Shock resistance rated at 15g / 11 ms, so it holds up on vibrating equipment like sorters or palletizers.
Input characteristics and bus loading
Inputs are PNP — switch High above 10 V, draw minimum 6 mA at signal 1 and maximum 1.5 mA at signal 0. The total AS-Interface current draw is capped at 270 mA (at 40 °C ambient, 200 mA). That bus current includes the sensor supply for all four inputs, so factor in the sensor loads when calculating the AS-i power budget.