Siemens 6ES7221-1BH32-0XB0 Product Description
2026-04-10
ExcerptSiemens 6ES7221-1BH32-0XB0 is a 16-channel digital input module for SIMATIC S7-1200 PLCs, supporting 24V DC input and IP20 protection. It ensures stable industrial automation control with flexible parameterization and wide environmental adaptability.
The Siemens 6ES7221-1BH32-0XB0 belongs to the SIMATIC S7-1200 series, a high-performance digital input module designed for industrial automation control systems. It integrates 16 digital input channels, suitable for connecting various 24V DC sensors and switches in industrial sites. This module adopts reliable circuit design and high-quality materials to ensure stable operation in harsh industrial environments, making it widely used in manufacturing, processing, and other automation fields. The 6ES7221-1BH32-0XB0 is easy to install and parameterize, which can effectively improve the efficiency of system debugging and operation.
Technical Specifications
Power Supply Parameters
The rated power supply voltage of the 6ES7221-1BH32-0XB0 is DC 24V, with a permissible range from 20.4V to 28.8V. It draws a maximum current of 130mA from the backplane bus at 5V DC, ensuring stable power supply for long-term operation. The typical power loss of the module is 2.5W, which is energy-saving and suitable for low-power automation systems.
Digital Input Parameters
The 6ES7221-1BH32-0XB0 is equipped with 16 digital input channels, divided into groups of 4 for convenient management and wiring. Each channel supports both sink and source input types, complying with IEC 61131 Type 1 input characteristics. The rated input voltage is DC 24V, with a signal “0” at 5V DC (1mA) and signal “1” at 15V DC (2.5mA).
For signal “0”, the maximum permissible quiescent current is 1mA; for signal “1”, the minimum current is 2.5mA and the typical current is 4mA. The input delay is parameterizable, with options of 0.2ms, 0.4ms, 0.8ms, 1.6ms, 3.2ms, 6.4ms and 12.8ms, selectable in groups of four. Interrupt inputs are also parameterizable to meet different control needs.
Environmental Tolerance
The6ES7221-1BH32-0XB0 has excellent environmental adaptability, with an operating ambient temperature ranging from -20°C to 60°C. The permissible temperature change is 3°C per minute between 5°C and 55°C, suitable for areas with large temperature fluctuations. During storage and transportation, it can withstand temperatures from -40°C to 70°C.
The module can operate at a relative humidity of up to 95% at 25°C without condensation, and can withstand air pressure between 660 hPa and 1080 hPa during storage and transportation. It has an IP20 protection level, effectively preventing dust and small objects from entering and ensuring internal component safety.
Mechanical Parameters
The 6ES7221-1BH32-0XB0 has a compact design with a width of 45mm, height of 100mm, and depth of 75mm, saving installation space in the control cabinet. The front enclosure is made of high-quality plastic, which is durable and corrosion-resistant. The module’s gross weight is 210g, making it easy to handle and install.
Wiring and Anti-Interference
The 6ES7221-1BH32-0XB0 supports a maximum shielded cable length of 500m and unshielded cable length of 300m, allowing flexible wiring in large industrial sites. It has good anti-interference ability, with potential separation between channels in groups of 4, effectively reducing signal interference from external equipment.
Installation Guide
Before installing the 6ES7221-1BH32-0XB0, ensure the power of the S7-1200 PLC system is turned off to avoid electrical damage. The module is installed on the DIN rail of the control cabinet, and you can directly snap it into the rail for quick fixing.
Connect the power supply and input signals according to the wiring diagram on the module’s front panel. Use a suitable front connector to connect the 24V DC power supply and sensor signals, ensuring correct polarity to prevent module failure. After wiring, check all connections to ensure they are firm and free of loose contacts.
The module can be installed in both horizontal and vertical positions, and up to 16 channels can be used simultaneously at temperatures up to 40°C. When the temperature exceeds 40°C, ensure proper ventilation in the control cabinet to maintain stable module operation.
After installation, power on the system and use the programming software to parameterize the input delay and interrupt functions according to actual control requirements. Check the LED indicator lights on the module to confirm that each input channel works normally.
Packaging List
1 x Siemens 6ES7221-1BH32-0XB0 Digital Input Module 1 x Front Connector (matching the module) 1 x Installation Manual (English version) 1 x Protective Cover (for module front panel)
We ship the product via Fedex, UPS, or DHL, and you can choose the most suitable shipping method according to your location and needs. The shipping time varies by region, usually 3-7 working days.
Frequently Asked Questions (FAQ)
Q1: What is the difference between the 6ES7221-1BH32-0XB0 and 6ES7221-1BF32-0XB0?
The main difference lies in the number of input channels: the 6ES7221-1BH32-0XB0 has 16 digital input channels, while the 6ES7221-1BF32-0XB0 has only 8 channels. Both modules support 24V DC input and have the same power supply and environmental parameters.
Q2: Can the 6ES7221-1BH32-0XB0 be used with other brands of PLCs?
No, the 6ES7221-1BH32-0XB0 is specially designed for Siemens SIMATIC S7-1200 series PLCs. It is not compatible with PLCs of other brands due to differences in bus communication protocols and mechanical structure.
Q3: Why does the 6ES7221-1BH32-0XB0 input signal fail to be detected?
First, check if the power supply voltage is within the permissible range (20.4V-28.8V). Then check the wiring polarity and connections to ensure no loose or wrong wiring. You can also check the input delay parameter settings and adjust them to appropriate values.
Q4: What is the maximum cable length supported by the 6ES7221-1BH32-0XB0?
The module supports a maximum shielded cable length of 500m and unshielded cable length of 300m. Using shielded cables can effectively reduce external signal interference and ensure stable input signal transmission.
Q5: Can the 6ES7221-1BH32-0XB0 operate normally in high-humidity environments?
Yes, the module can operate at a relative humidity of up to 95% at 25°C without condensation. However, you should avoid direct contact with water or corrosive gases to prevent damage to internal components.
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