6ES7521-1BH00-0AB0

Reliable digital input module 6ES7521-1BH00-0AB0 for S7-1500 systems

The Siemens 6ES7521-1BH00-0AB0 is a high-feature digital input module designed for the SIMATIC S7-1500 series. It provides 16 digital inputs operating at 24V DC. Two of these inputs can be used as high-speed counters. The module features configurable input delay ranging from 0.05 ms to 20 ms, and it supports diagnostic functions and hardware interrupts. This ensures reliable signal acquisition, fast reaction times, and high operational flexibility for industrial control applications.

Technical specifications

• Input channels: 16 digital inputs, 24V DC

• Counter inputs: 2 channels configurable as counters

• Input delay: adjustable from 0.05 ms to 20 ms

• Input type: IEC 61131 Type 3

• Diagnostic functions: supported (status monitoring, hardware interrupts)

• Supply voltage (input side): 24V DC

• Current consumption (input side): max 20 mA

• Power loss: approx. 2.6 W

• Bus current (backplane): approx. 1.1 W

• Isolation test voltage: 707V DC

• Dimensions: approx. 15.0 cm × 15.1 cm × 5.0 cm

• Weight: approx. 277 g

Key advantages

• 16-channel module for high-density signal collection

• Two inputs usable as fast counters

• Configurable delay time for optimized performance

• Diagnostic and interrupt support for advanced monitoring

• Reliable integration with S7-1500 automation systems

Application and use cases of 6ES7521-1BH00-0AB0

This module is used in various industrial applications, including machine automation, production lines, process control, and monitoring systems where high input density and diagnostics are essential. Its ability to handle counter inputs and adjustable response time makes it suitable for both fast and sensitive input signal processing.

About the manufacturer

Siemens is a global technology leader in industrial automation. Its SIMATIC S7-1500 system is known for high performance, modularity, and precise control. The 6ES7521-1BH00-0AB0 module contributes to building scalable and reliable automation architectures.