What it is and what it does
The Siemens 6ES7223-1PH30-0XB0 is an S7-1200 signal module combining 8 digital inputs (sinking/sourcing) with 8 relay outputs, each capable of switching 5 V AC to 250 V AC or 5 to 30 V DC loads. The relay outputs are isolated between channels, which means a shorted output doesn't cascade to its neighbor—a consideration for panel reliability over time. Wide operating range from -40 °C to 70 °C allows installation in unheated warehouses or cold-chain environments without derating—fewer cold-early-life failures than standard 0–55 °C I/O.
Key electrical and mechanical ratings
Power dissipation is 5.5 W typical; at 70 °C ambient the module derates its output current per channel to stay within the package limit. The 230 g module occupies 45 mm width on the DIN rail, leaving room for an extra module in the same rail slot compared to wider 8-point bricks. Input characteristics: a logic '1' is guaranteed at 15 V DC, 2.5 mA, and sourcing 2.5 mA min; logic '0' is below 5 V DC at 1 mA. This 15 V threshold makes it less susceptible to noise-induced false counts than low-threshold 24 V logic.