Sep 11, 2026Buying Guides
Siemens S7-1200 G2 SM 1221 6ES7221-1BH50-0XB0 Digital Input Module
Explore the Siemens SIMATIC S7-1200 G2 SM 1221 6ES7221-1BH50-0XB0 digital input module with 16 DI, 24V DC sink/source inputs for industrial automation applications.
Siemens SIMATIC S7-1200 G2 SM 1221 6ES7221-1BH50-0XB0 Digital Input Module
The Siemens SIMATIC S7-1200 G2 SM 1221 6ES7221-1BH50-0XB0 is a digital input signal module designed for the SIMATIC S7-1200 G2 automation system. Featuring 16 digital inputs at 24 V DC with sink/source capability, the SM 1221 provides additional digital input capacity for industrial control and machine automation applications.
For engineers, system integrators and maintenance teams searching by exact Siemens article number, 6ES7221-1BH50-0XB0 is an important identifier to verify before purchasing or specifying the module.
Key Product Information
Manufacturer: Siemens
Product Family: SIMATIC S7-1200 G2
Module: SM 1221
Article Number: 6ES7221-1BH50-0XB0
Product Type: Digital Input Module
Digital Inputs: 16 DI
Input Voltage: 24 V DC
Input Type: Sink/Source
What Is the Siemens SM 1221 Used For?
Digital input modules allow a PLC system to receive ON/OFF signals from field devices. Depending on the system design, these signals may come from sensors, switches, push buttons or other digital devices used in industrial machinery.
The S7-1200 G2 SM 1221 expands the digital input capability of a compatible automation system, making it useful when a control project requires more input points than the CPU configuration alone provides.
Typical applications can include machine control, equipment automation, production systems and electrical control panels.
Why the Exact Part Number Matters
When sourcing Siemens automation components, checking only the product family or “SM 1221” designation is not sufficient. Modules within a product family can have different electrical characteristics and configurations.
For this product, buyers should verify the complete article number:
6ES7221-1BH50-0XB0
This helps reduce the risk of selecting a module with an incorrect I/O configuration or electrical specification.
Looking for 6ES7221-1BH50-0XB0?
BOSTENE supplies industrial automation, electrical control and power distribution products. If you are sourcing the Siemens SIMATIC S7-1200 G2 SM 1221 6ES7221-1BH50-0XB0, send us the part number, required quantity and destination country for product and quotation information.
For multi-item projects, you can also send your PLC or electrical BOM list for sourcing assistance.