The 6ES7521-1FH00-0AA0 is a 16-channel digital input module for SIMATIC S7-1500 systems, accepting AC signals from 0 to 264 V AC. Rated input at 120/230 V AC, it reads line-level field devices without step-down transformers. Every channel scans in under 25 ms, configurable for source or sink wiring (P-reading). Power draw is a typical 4.9 W, so thermal load in a packed cabinet is modest. I&M data 0–3 is included for asset tagging.
Integration Notes
Mounts on S7-1500 DIN rail (35 mm width, 129 mm depth, 147 mm height). No shielded cable required up to 1 000 m; unshielded max 600 m. Signal '0' threshold 0–40 V AC, signal '1' 79–264 V AC. Typical input current 11 mA at 230 V AC, 5.5 mA at 120 V AC. Firmware V2.0.0, field-upgradable. Isolation tested at 3 100 V DC between channels and backplane; 500 V AC between channels themselves. The green RUN and channel status LEDs give quick visual on power and each input.