Module overview
Siemens SIPLUS 6AG1131-4BD01-2AA0 is a 4-channel digital input module for the SIMATIC S7-1200 system. It accepts 24 V DC signals from switches, pushbuttons, or 2-wire proximity sensors. Each input is reverse-polarity protected and optically isolated from the backplane bus. The sensor supply output provides up to 500 mA total for the 2-wire loop — enough for four standard sensors at 7 mA each plus reserve.
Compliance: CE marked, isolation tested at 500 V DC.
Input characteristics and field wiring
Signal '0' threshold: -30 to +5 V. Signal '1' guaranteed from +15 to +30 V. Typical current draw per channel at 24 V is 7 mA. Response time 2 ms to 4.5 ms for both on-to-off and off-to-on transitions — fast enough for most discrete sensing but not encoder tracking. Module dimensions: 15 mm wide, 81 mm high, 52 mm deep — fits one S7-1200 signal slot. Maximum sensor cable length 1 000 m shielded, 600 m unshielded. Address space 1 byte; parameterization not supported (fixed configuration).