Product Overview
The Siemens 6ES5375-0LC31 is a precision-engineered EEPROM memory submodule belonging to the world-renowned SIMATIC S5 programmable logic controller family, purpose-designed to provide non-volatile program and data storage for S5-115U central controllers and compatible S5 CPU platforms. As a member of Siemens’ 375-series memory submodule family, the Siemens 6ES5375-0LC31 employs advanced EEPROM (Electrically Erasable Programmable Read-Only Memory) technology to permanently retain user programs, data blocks, and critical configuration parameters without requiring battery backup—a decisive advantage over both UV-EPROM submodules (which demand periodic ultraviolet erasure) and battery-backed RAM submodules (which risk catastrophic data loss upon battery depletion). According to Siemens’ official Industry Support documentation, the Siemens 6ES5375-0LC31 delivers 16 Kbytes of EEPROM storage capacity and is programmed using Programming Number 211 within the STEP 5 engineering environment, making it the standard, field-proven memory solution for S5-115U CPU 941/942/943/944 class controllers.
The core value proposition of the Siemens 6ES5375-0LC31 lies in its seamless integration into the S5 CPU architecture. The submodule plugs directly into the dedicated memory slot on the top of the S5-115U CPU module, drawing its 5V DC operating power directly from the CPU backplane—no external power supply, no separate wiring, no additional interface hardware. Once the user program is downloaded into the CPU’s internal RAM via STEP 5, a simple “Copy” button press (or equivalent STEP 5 copy function) transfers the entire program and data block contents from volatile RAM into the Siemens 6ES5375-0LC31 EEPROM. On subsequent power cycles, cold starts, or battery-related RAM clears, the CPU automatically reloads the program from the Siemens 6ES5375-0LC31 back into working RAM, ensuring deterministic, unattended system recovery. This electric erase-and-rewrite capability—achievable directly within the CPU without removing the submodule or exposing it to ultraviolet light—fundamentally distinguishes the Siemens 6ES5375-0LC31 from older UV-EPROM technology and explains its enduring popularity among S5 maintenance engineers.
With a compact 28-pin DIP form factor, approximately 0.042 kg of weight, and an operating temperature range of 0°C to +60°C (with storage capability from -40°C to +85°C), the Siemens 6ES5375-0LC31 is built to Siemens’ exacting industrial standards. Although Siemens has officially declared the entire SIMATIC S5 platform—including the Siemens 6ES5375-0LC31—as end-of-life, this submodule remains an absolutely mission-critical component in countless operational S5-115U installations worldwide. For facility managers and maintenance engineers responsible for sustaining legacy SIMATIC S5 automation assets, the Siemens 6ES5375-0LC31 represents a lifeline: a tested, warrantable spare part that can be inserted into an existing CPU to restore full non-volatile program storage in a matter of seconds. Its continued availability through specialized industrial automation spare parts suppliers ensures that investments in S5-115U-based automation can be protected and maintained for decades to come.
Technical Specifications
| Parameter Name | Parameter Value |
|---|---|
| Product Model | 6ES5375-0LC31 (6ES5 375-0LC31) |
| Manufacturer | Siemens AG |
| Product Type | EEPROM Memory Submodule (375 Series) |
| Series | SIMATIC S5 › 375 Memory Submodules |
| Memory Technology | EEPROM (Electrically Erasable Programmable ROM) |
| Storage Capacity | 16 Kbytes (per Siemens Industry Support); market literature also references 8KB variants |
| Programming Number | 211 (within STEP 5 EPROM selection) |
| Applicable CPU | SIMATIC S5-115U (CPU 941/942/943/944 class) |
| Installation | Plug-in to dedicated memory slot on top of S5-115U CPU module |
| Form Factor | 28-pin DIP (Dual Inline Package) |
| Operating Voltage | 5V DC (via CPU backplane) |
| Operating Current | Typically < 10 mA (max. 20 mA per some specifications) |
| Data Retention | Permanent—no battery required; nominal ≥ 10 years at room temperature |
| Erase/Write Method | Electric erase and rewrite via CPU “Copy” button or STEP 5 function |
| Write Endurance | Effectively unlimited compared to UV-EPROM (~100 erase cycles) |
| Program Elements | Up to 384 program elements (for 2KB variant class) |
| Operating Temperature | 0°C to +60°C (some specs: -25°C to +60°C) |
| Storage Temperature | -40°C to +85°C |
| Protection Class | IP20 (installation within CPU module, control cabinet required) |
| Dimensions (W×H×D) | Approx. 50 × 100 × 20 mm |
| Weight | Approx. 0.042 kg |
| Commodity Code | 85389091 |
| Product Status | Discontinued (Siemens official EOL) – available as spare part |
| Typical Warranty | 12–24 months (from specialized suppliers) |
