Siemens SIMATIC S7-300 CPU 312C Compact PLC – 6ES7312-5BF04-0AB0, 64 KB Work Memory

The Siemens SIMATIC S7-300 CPU 312C Compact CPU (6ES7312-5BF04-0AB0) is a compact programmable logic controller designed for industrial automation, machine control, and process applications. It combines a PLC processor, integrated digital inputs and outputs, high-speed counting functions, and an integrated 24 V DC power supply in one compact module.

This CPU provides 64 KB of work memory, 10 digital inputs, 6 digital outputs, and two integrated high-speed counters operating at up to 10 kHz. Its MPI communication interface supports connection to compatible Siemens programming devices and operator panels. A compatible Siemens Micro Memory Card (MMC) is required for program and load-memory storage.

The CPU 312C is suitable for compact automation tasks and maintenance of existing SIMATIC S7-300 systems where its integrated I/O configuration and communication capabilities meet the application requirements.

Technical Specifications

Key Features

• Compact PLC design: Combines the CPU and digital I/O in one module to simplify smaller automation installations.

• 64 KB work memory: Supports execution of compatible PLC control programs.

• Integrated digital I/O: Includes 10 digital inputs and 6 digital outputs.

• High-speed counting: Two integrated counters support applications requiring counting frequencies up to 10 kHz.

• MPI communication: Connects to compatible Siemens programming devices and operator interfaces.

• Integrated 24 V DC power supply: Supports compatible S7-300 installation requirements.

• Micro Memory Card support: Provides the required load memory for program storage.

• Legacy system compatibility: Useful for maintaining existing equipment built around the CPU 312C.

Applications

• Compact industrial machine automation

• Packaging and assembly equipment

• Digital signal monitoring and control

• Pulse counting and frequency measurement

• Production-line automation

• Machine sequencing and interlocking

• Maintenance and refurbishment of existing Siemens S7-300 installations

Compatibility and Installation Notes

Before purchasing, confirm the exact part number, wiring arrangement, integrated I/O requirements, front connector, Micro Memory Card, and STEP 7 project compatibility. The CPU 312C has an MPI interface and does not have integrated PROFINET or PROFIBUS DP interfaces. Additional communication functionality may require compatible expansion or communication modules.

Availability notice: Siemens lists this model under its product phase-out announcement, effective October 1, 2023. Availability may depend on remaining stock and specialist automation suppliers. Confirm whether the unit is new, refurbished, or used, and verify warranty and authenticity before ordering.