S7-1200 SM 1223 – 8DI / 8DO Relay
This is a Siemens S7-1200 signal module, order code 6AG1223-1PH30-2XB0, providing eight digital inputs and eight relay outputs in a single 45 mm wide slice. Inputs are 24 V DC sinking (signal “1” at 15 V DC, 2.5 mA min, 4 mA typ) with a 10 ms transition time in both directions. Relay outputs are isolated per channel and rated for lamp loads up to 30 W DC or 200 W AC, and general AC loads up to 250 V AC. Diagnostic alarm and status indication are supported per channel, and the module is parameterizable. A front connector is required separately; short-circuit protection must be provided externally on the output wiring.
Integration Notes
The module fits the standard S7-1200 I/O rack and is addressed via the backplane bus. Unshielded cable runs up to 150 m for inputs; shielded runs up to 500 m. Input groups of two share a common reference. For relay outputs, note the lamp load limits: 30 W DC, 200 W AC — exceed these with incandescent inrush and the contacts may weld. The relays are between-channel isolated, so each output can switch a separate potential. Maximum fall height in packaging is 0.3 m five times — not a panel concern, but good to note for incoming inspection.