Siemens 6ES7212-1HF40-0XB0 PLC Module 24VDC
The Siemens 6ES7212-1HF40-0XB0 is a CPU 1212C from the SIMATIC S7-1200 family of compact programmable logic controllers. This version operates on 24V DC (sink/source), has 6 digital inputs and 8 relay outputs onboard, and is designed for small automation tasks requiring real-time processing. The module can be expanded with up to two signal boards and eight signal modules, making it highly scalable.
Onboard I/O Specifications
Digital inputs: 6 points, 24V DC (sink/source), input current 4 mA typical. Two of the inputs can be used as high-speed counters (up to 100 kHz). Inputs feature adjustable debounce (0.1 to 12.8 ms). Digital outputs: 8 relay outputs (SPST-NO), rated for 2 A resistive load (30V DC / 250V AC). Outputs are individually isolated and have LED status indicators. The total current per common (2 groups of 4) is 10 A.
Power Supply
The CPU requires a 24V DC nominal supply (20.4–28.8V). Power consumption is 10 W typical. An internal 24V DC sensor supply (300 mA) is available for powering digital inputs or external devices. The power supply is protected against reverse polarity and transients according to IEC 61131-2.
Processing and Memory
The CPU 1212C uses a 32-bit ARM Cortex processor with a cycle time of 0.08 µs for bit instructions. Program memory: 75 KB (working memory), 4 MB load memory (integrated), and 2 MB retentive memory (EEPROM). The real-time clock (RTC) has a 20-day backup capacitor (no battery required). Firmware version as of 6ES7212-1HF40-0XB0 is V4.5.
Communication Interfaces
Integrated PROFINET port (RJ45, 2-port switch) supports 16 Ethernet connections. Protocols: PROFINET IO (controller or device), TCP/IP, Modbus TCP, and S7 communication. An additional RS-232/485 port can be added via a CM 1241 communication module. The CPU also supports a web server for diagnostics and data visualization.
Expansion Capabilities
Up to 2 signal boards (SB, plug-in on front) and 8 signal modules (SM, side expansion) can be added. Maximum digital I/O: 284 points (with expansion). Maximum analog I/O: 28 points. The CPU also supports up to 3 communication modules (CM) and 3 technology modules (TM). All expansion modules are automatically recognized by TIA Portal.
Programming with TIA Portal
The controller is programmed using Siemens TIA Portal (STEP 7 Basic V15.1 or higher). Languages: LAD, FBD, SCL, and GRAPH. The CPU supports 6 motion control axes (PTO outputs) for stepper motors or servos. Built-in PID controllers (4 channels) with auto-tuning are available for process applications.
Environmental and Physical
Dimensions: 100 mm width x 75 mm height x 75 mm depth. Weight: 350 g. Mounting: DIN rail (35 mm) or panel mounting via integrated clips. Operating temperature: -20°C to +60°C (horizontal), -20°C to +50°C (vertical). Protection class: IP20. The housing is rated UL94 V-0.
Diagnostics and LEDs
Multi-color status LEDs: RUN/STOP, ERROR (red), MAINT (yellow), and I/O status for each channel. The CPU stores up to 200 diagnostic events in a buffer, accessible via TIA Portal or web server. A removable microSD card (up to 32 GB) can be used for program backup, data logging, and firmware updates.
Compliance and Certifications
Certified to CE, cULus, ATEX Zone 2, IECEx, and C-Tick. RoHS compliant. The 6ES7212-1HF40-0XB0 meets marine classification (DNV GL) and has a SIL 2 rating for functional safety (when used with safety-rated I/O). Order includes a set of terminal connectors and a power plug.
Typical Applications
Ideal for conveyor systems, packaging machines, small pumping stations, and HVAC control. The relay outputs directly switch contactors, solenoid valves, and small motors (up to 0.3 kW at 230V AC). The integrated high-speed counters support encoder feedback for cut-to-length applications.
