Siemens 6ES7221-1BH32-0XB0 CPU 1212C

Compact Controller for Small to Medium Applications

This CPU 1212C delivers powerful control capabilities in a compact form factor. It combines integrated I/O with communication ports for versatile connectivity. Many machine builders choose this controller for space-constrained automation tasks. The unit offers excellent performance for basic to intermediate applications.

Technical Specifications

Parameter	Specification
Model	6ES7221-1BH32-0XB0
Dimensions	90 mm × 100 mm × 75 mm (W × H × D)
Weight	0.40 kg
Power Supply	24 V DC
Power Consumption	10 W typical
Program Memory	30 KB (integrated)
Data Memory	20 KB (integrated)
Load Memory	2 MB (integrated)
Digital Inputs	8 × 24 V DC (sink/source)
Digital Outputs	6 × 24 V DC, 0.5 A (transistor)
Onboard I/O Count	14 (8 inputs, 6 outputs)
Max I/O Expansion	Up to 284 (using signal modules)
Built-in Communication	1 × PROFINET (RJ45), 1 × RS-485 (optional)
PROFINET Port	10/100 Mbps (2-port switch)
Ethernet Protocols	TCP/IP, ISO-on-TCP, S7-communication
Bit Instruction Speed	0.08 µs
Word Instruction Speed	1.7 µs
Real-Time Clock	Yes (battery-backed)
Timer/Counter	256 timers, 256 counters
Interrupts	32 hardware, 16 software
Operating Temperature	0°C to +55°C
Storage Temperature	-40°C to +70°C
Humidity Range	5% to 95% RH (non-condensing)
Protection Class	IP20
Certifications	CE, UL, cULus, ATEX, FM

Integrated I/O and Onboard Features

This CPU includes 8 digital inputs and 6 transistor outputs onboard. The inputs accept 24 V DC signals from sensors and pushbuttons. Transistor outputs drive small solenoids, relays, and indicator lamps. This built-in I/O reduces additional module requirements for basic applications.

Processing Performance and Execution Speed

The CPU executes bit instructions in 0.08 microseconds. Word instructions complete in 1.7 microseconds for efficient data processing. This speed suits applications requiring moderate scan times. The controller handles 30 KB of program memory effectively.

Memory Architecture and Storage Capacity

Program memory holds 30 KB of user logic and code. Data memory provides 20 KB for process variables. Load memory of 2 MB stores project data and firmware. This memory supports typical small to medium automation tasks.

Communication Capabilities and Networking

A built-in PROFINET port supports 10/100 Mbps network connections. The integrated 2-port switch enables line topology configurations. Ethernet protocols include TCP/IP and S7-communication. This connectivity links the CPU to HMIs, drives, and SCADA systems.

Expansion Capabilities and System Scalability

The CPU supports up to 284 I/O points using signal modules. Users can add digital, analog, and communication modules as needed. This scalability protects initial investment while allowing future expansion. The modular design adapts to changing requirements.

Interrupt Functions and Real-Time Response

Thirty-two hardware interrupts handle high-priority events immediately. Sixteen software interrupts support periodic tasks and scheduling. Interrupt routines execute independently of the main scan. This architecture ensures fast response to critical field signals.

Mechanical Construction and Physical Specifications

This controller measures 90 mm wide and weighs 0.40 kg. The compact footprint saves space in small control panels. IP20 protection suits installation inside enclosures and cabinets. Standard DIN rail mounting simplifies installation and replacement.

Safety Certifications and Approvals

The 6ES7221-1BH32-0XB0 holds CE, UL, cULus, ATEX, and FM certifications. These approvals permit use in industrial and hazardous environments. Each unit undergoes quality testing before shipment. This commitment ensures reliable operation in diverse applications.