Siemens 6ES7 521-1BH50-0AA0 Digital Input Module

Siem​ens 6ES7521-1BH50-0AA0 Digital Input Module (DI 16x24 V DC BA, SRC) is a 16‑channel digital input card for SIMATIC S7‑1500 systems. This SRC (sourcing) 24 V DC input module provides 16 digital inputs arranged in a 16‑channel block, with an input delay of 3.2 ms and input type 3 (IEC 61131) operation for predictable timing in automation logic. Front connectors (screw terminals or Push‑In) are ordered separately to fit your panel design. As part of the SM 521 digital input family, it is designed to mount in compatible S7‑1500 I/O configurations via the standard SM 521 interface. The 16 DI channels are intended for connection to 24 V DC sensors and switches, enabling straightforward machine control, process monitoring, and automation tasks in industrial environments. The module’s compact 16‑channel footprint simplifies wiring for multi‑sensor applications and supports integration into STEP 7 or TIA Portal configurations for S7‑1500 projects.