4 outputs, 2 A each — the current budget that matters
The Siemens 6ES7148-1CA00-0XB0 PM 148 power module delivers four digital outputs, each rated 2 A at 24 V DC. That per-channel rating is the headline, but the real constraint is the total current: 6 A up to 20 °C, dropping to 4 A at 55 °C. If you're driving four solenoid valves at 1.5 A each, you're fine at 20 °C — at 55 °C you're over the limit and need to derate the load or add cooling. Channel-level diagnostics catch wire-break and short-circuit per output, with a parameterizable diagnostic alarm and a red group-error SF LED. That means a single bad solenoid or a pinched cable flags the exact channel, not just a vague module fault — saves hours of panel chasing on a line-down call.
The module measures 87 mm wide (module body 60 mm) × 165 mm high × 67 mm deep including the connector. The 67 mm depth includes the front connector, so account for that when routing wires to the gland plate. Power dissipation is 2.5 W typical, and the module draws 40 mA max from the 5 V DC backplane bus plus 60 mA max from the 24 V load voltage when unloaded. The 24 V load voltage has a green monitoring LED — if that's out, the outputs won't fire, and the diagnostics will flag a load-voltage fault.