This is a Siemens SIPLUS 6AG1526-1BH00-2AB0 — a heavily instrumented 16-input, 4-output digital module for S7-1500 racks, built with diagnostic gating and SIL3-rated separation. You bring 24 V DC to the backplane (tolerates down to L+ minus 1.5 V) and connect your dry contacts or transistor drivers to the inputs; the four outputs each handle up to 300 mA, though derate to 100 mA if the module is mounted vertically. Width is 35 mm; typical power loss 4.6 W. Shielded cable max. 1 000 m; unshielded 500 m.
Diagnostics and safety integration
The module reports a diagnostic alarm via backplane and has per-channel short-circuit detection. It is SIL 3 certified. Filters are configurable: minimum on/off time is 0.4 ms, maximum 20 ms, so you can reject contact bounce on mechanical limit switches or tighten the window for encoder-style signals.