The 6ES7223-1PH22-0XA0: This is a Siemens EM 223 expansion module — 8 digital inputs and 8 relay outputs in one 71.2 mm-wide housing. It snaps onto the S7-200 rail and draws power from the backplane or an external 24 V DC supply (72 mA max). The inputs accept 15–30 V DC for signal '1', with a 4.5 ms max turn-on time; the relay outputs switch up to 0.75 A each on resistive or inductive loads, with mechanical endurance rated at 10 million cycles and 100,000 at rated load voltage.
Supply flexibility and isolation
The module runs on either 24 V DC or 24–230 V AC — same terminals, no jumper change. Inputs are optocoupler-isolated from the backplane; outputs are relay-isolated in groups of four. Isolation tested at 500 V AC between channels and the bus. That means you can land different field potentials on the same module without chasing ground loops — useful when half the panel runs 24 V sensors and the other half 120 V pilot lights.