The Siemens 3RK1200-0CG03-0AA2 is an AS-Interface counter module in the SIRIUS form factor — a single digital input configured as a counter, PNP-sensed, drawing its operating voltage from the AS-Interface bus at 26.5 to 31.6 V and pulling up to 170 mA total from the bus. It provides one counter input with a 90 mA sensor supply at 40 °C, short-circuit and overload protected, so it can power a proximity sensor or encoder directly off the module without an external supply. The switching thresholds are defined: a High signal starts at 10 V minimum, a Low signal is 5 V maximum, and the input sinks 10 mA minimum at High, 2 mA maximum at Low.
Housed in a 22.5 mm wide enclosure (103 mm tall, 86 mm deep) that clips onto standard 35 mm DIN rail per EN 50022 or can be wall-mounted. Connections are via spring-loaded terminals accepting 2 x (0.25 to 1.5) mm² solid or 2 x (0.25 to 1) mm² with end sleeve; AWG 24 to 16 stranded. Pin assignment: terminal 7 is + (sensor supply), terminal 9 is – (common), terminal 8 is the counter input IN2.
Status and diagnostics
A bicolor LED on the front reports AS-Interface bus health: green on with red off means normal operation; green off with red on means no data traffic; green flashing with red on means zero address; green off with red flashing means sensor overload.