Siemens 6ES7 521-1BL00-0AB0 Digital Input Module

Siemens 6ES7521-1BL00-0AB0 DI 32x24 V DC HF digital input module is a 32-channel digital input card for SIMATIC S7-1500 systems. It provides 32 channels of 24 V DC inputs, arranged in two groups of 16, and supports using two inputs as counters for high-frequency counting. The module features an input delay of 0.05 to 20 ms (IEC 61131 Type 3), built-in diagnostics, and hardware interrupts. Power consumption from the backplane bus is 1.1 W, and the front connector (screw terminals or push-in) must be ordered separately. This module is designed to read field signals from sensors and switches in automation tasks such as machine controls, conveyors, and safety interlocks, and integrates with the S7-1500 family.