Siemens 6ES7-221-1BF30-0XB0 Digital Input Module

Siemens SM1221 digital input module, 8 x 24 VDC, 6ES7-221-1BF30-0XB0 (old order number) now superseded by 6ES7-221-1BF32-0XB0, is an eight-channel digital input block for SIMATIC S7-1200 systems. It provides eight 24 V DC inputs that can be wired either sink or source, enabling direct connection of sensors and switches to the CPU via the SM 1221 signal module bus. As part of the SM 1221 family, it expands discrete input capability in automation projects and supports common uses such as monitoring machine signals or safety interlocks. This module is designed for industrial automation environments where compact I/O expansion of digital inputs is required.