Product Overview
When reliable digital input acquisition is critical, the Siemens 6ES7221-1BH32-0XB0 delivers robust performance. This SIMATIC S7-1200 SM 1221 module provides 16 digital inputs at 24 V DC, configured as sink/source. Engineered for industrial environments, the Siemens 6ES7221-1BH32-0XB0 offers parameterizable input delays and diagnostic capabilities, ensuring minimal downtime and long-term cost efficiency.
Technical Specifications
| Parameter |
Value |
| Product Type Designation |
SM 1221, DI 16x24 V DC |
| Rated Supply Voltage (DC) |
24 V |
| Supply Voltage Range |
20.4 V – 28.8 V |
| Input Current from Backplane Bus |
5 V DC, max. 130 mA |
| Number of Digital Inputs |
16 (in groups of 4) |
| Input Characteristic Curve |
IEC 61131, Type 1 |
| Rated Input Voltage (DC) |
24 V |
| Signal '0' Voltage/Current |
5 V DC at 1 mA |
| Signal '1' Voltage/Current |
15 V DC at 2.5 mA |
| Input Delay (Parameterizable) |
0.2 ms to 12.8 ms (selectable in groups of four) |
| Power Loss (Typical) |
2.5 W |
| Dimensions (W x H x D) |
45 mm x 100 mm x 75 mm |
| Weight |
Approx. 210 g |
| Degree of Protection |
IP20 |
These parameters, drawn directly from the Siemens 6ES7221-1BH32-0XB0 datasheet, enable precise integration into automation architectures.
Industry Applications
The Siemens 6ES7221-1BH32-0XB0 excels in applications requiring high-density digital input acquisition. Common use cases include packaging machinery, conveyor systems, and material handling where 24 V DC sensor signals must be reliably captured. Its ability to handle up to 16 simultaneous inputs (up to 40 °C) supports scalable machine designs. The parameterizable input delays allow optimization for diverse sensor types, reducing false triggering and improving process reliability—directly supporting a lower total cost of ownership.
Installation & Setup Guidance
Mount the Siemens 6ES7221-1BH32-0XB0 on a standard DIN rail within an S7-1200 system. Connect the front connector (required) according to wiring diagrams for sink/source configurations. Use shielded cables up to 500 m or unshielded up to 300 m. Ensure the supply voltage remains within 20.4 V to 28.8 V DC. The module's IP20 rating requires installation in a protected cabinet. No special tools are needed for installation.
Maintenance & Reliability
To maximize ROI, periodically inspect the Siemens 6ES7221-1BH32-0XB0 for loose connections and environmental factors. The module operates reliably from -20 °C to 60 °C and withstands storage temperatures from -40 °C to 70 °C. With diagnostic alarms and status LEDs, maintenance staff can quickly identify input faults, minimizing downtime. The plastic enclosure ensures durability in standard industrial environments.
Selection Guide & Purchasing Advice
Before purchasing the Siemens 6ES7221-1BH32-0XB0, verify compatibility with your SIMATIC S7-1200 controller and confirm the required number of input groups. No additional accessories are mandatory beyond the front connector (included in scope). For a reliable source of genuine Siemens 6ES7221-1BH32-0XB0 modules, consider ordering from PLC Source PRO (available at ubest101.myshopify.com) to ensure authentic parts and competitive pricing.