6ES7221-1BH50-0XB0, Siemens, SIMATIC S7-1200 G2 SM 1221, expansion module 16x digital inputs 24 V DC

6ES7221-1BH50-0XB0 – SIMATIC S7-1200 G2, SM 1221 – 16x digital inputs 24 V DC, Siemens

6ES7221-1BH50-0XB0 is a second-generation SM 1221 expansion module for the Siemens SIMATIC S7-1200 G2 with 16x digital inputs 24 V DC.

Technical specifications

Wiring diagram and example

Indicative wiring diagram for this module type. For an actual installation, always work from the current datasheet.

Digital input (PNP, sourcing): +24V ----+---[ PNP sensor ]---- DIx.x | 0V -----+------------------------ 1M The module draws its 24 V DC supply from the CPU backplane bus – no separate module supply is needed.

What else to buy for this module

The module belongs to an assembly with any CPU SIMATIC S7-1200 G2. Recommended related components:

• 6ES7212-1AG50-0XB0 – CPU 1212C DC/DC/DC
  Smaller CPU for smaller machines and switchboards.
• 6ES7214-1AH50-0XB0 – CPU 1214C DC/DC/DC
  Larger CPU with more integrated I/O and greater expandability.
• 6ES7954-8LE04-0AA0 – memory card 12 MB
  Program backup and easy CPU firmware updates.
• 6ES7822-0AE25-0YA5 – STEP 7 Basic V21, programming software
  Required for configuring the module in TIA Portal.
• SIMATIC S7-1200 G2 textbook – a guide to parameters and programming written in Czech
  Explains wiring of inputs/outputs and reading analogue values step by step.

Official Siemens documentation

The documents open directly in the manufacturer's sources and relate to the order number 6ES7221-1BH50-0XB0.

• Datasheet PDF
• Manuals and operating documentation
• Certificates and declarations
• Product page in SiePortal

Frequently asked questions

How do I verify the correct variant?

Compare the full order number 6ES7221-1BH50-0XB0 and the signal type (16x digital inputs 24 V DC). Models SM 1221 to SM 1233 exist in several variants differing in the number of channels and output type – a similar name is not enough.

Is the module compatible with all CPUs S7-1200 G2?

Yes, the module can be used with any CPU of the S7-1200 G2 series (1212C and 1214C, including fail-safe FC variants) within the maximum number of modules supported by the given CPU.

Is the module compatible with the original S7-1200 series?

No. The G2 generation uses its own range of modules with the order number suffix -50-0XB0, which is not interchangeable with the original series S7-1200.

How many of these modules can be connected to the CPU?

It depends on the CPU type: 1212C supports up to 6 SM/CM modules in total, 1214C up to 10. The number is reduced by each communication module (CM) used.

Alternative Kinco solution

For a new application, we can also design a Kinco control solution. Send us the application parameters; this is not an automatic direct one-for-one replacement.