The Siemens 3RK1207-0CG00-2AA2 is a Slimline Compact I/O module for control-cabinet use, part of the AS-i SC22.5 family. It provides four analog inputs for PT100 RTD temperature sensors, with a 16-bit A/D resolution. The module is a standard AS-Interface slave (profile S-7.3.E) and supports both 2-wire and 4-wire PT100 connections. Power delivery is flexible: the module draws 46 mA when supplied solely via the AS-Interface cable, or up to 500 mA when an auxiliary 20–30 V DC PELV supply (Uaux) is connected. The auxiliary feed also powers the output circuits and must comply with IEC 60990 (PELV), protection class III. The Uaux path can handle up to 4 A for external loads.
The analog inputs accept a wide range of signal types: 4–20 mA, ±20 mA, 1–5 V, and ±10 V. This means the module can interface with most common industrial temperature transmitters and linear sensors without an external signal conditioner. The 16-bit resolution gives roughly 0.01 °C steps on a PT100 input — adequate for process monitoring and HVAC applications. At 22.5 mm wide, it occupies a single standard DIN-rail slot. Screw and snap-on mounting means it clips onto the rail and can be secured with a screw for vibration resistance. Shock rating is 15g / 11 ms for the module alone, or 10g / 11 ms with the device connector attached — fine for most stationary industrial panels.
This module connects directly to an AS-Interface network, acting as a standard slave. The ID1 code is set to 'F' at the factory but is changeable via the front addressing socket. The module is also compatible with AS-i Power24V, which allows power and data on the same yellow cable up to 250 mA at 24 V. Wiring uses spring-cage terminals accepting 0.5–1.5 mm² solid or stranded wire (1 or 2 conductors), or 20–16 AWG. Fine-stranded wire with ferrules can be as small as 0.25 mm².