Siemens 6ES5375-1LA71 Memory Module

The Siemens 6ES5375-1LA71 Memory Module provides high-capacity program storage for SIMATIC S5-135U systems. This module uses EEPROM technology for electrical erasure without UV light. You will find it in large automation projects requiring frequent program updates. It stores user logic, parameters, and configuration data safely. Therefore, this unit eliminates the need for an external EPROM eraser.

The Siemens 6ES5375-1LA71 Memory Module measures 230 mm in height and 48 mm in width. Its depth reaches 180 mm for standard rack mounting. The unit weighs approximately 0.38 kilograms. It contains two EEPROM chips with a total capacity of 128 KB. No internal battery maintains data in this module. Additionally, you get one write-protect switch for data security.

Key Technical Specifications

Internal Architecture and Energy Storage

The Siemens 6ES5375-1LA71 Memory Module stores absolutely no electrical energy internally. It contains no capacitors or batteries at all. Two EEPROM chips provide 64 KB each for program and data storage. Each chip allows electrical erasure and reprogramming without UV light. A small PCB traces all 40 pins from the edge connector to the EEPROMs. The module uses parallel access for fast read operations. A mechanical write-protect switch prevents accidental data overwrites. When you slide the switch to PROTECT, the module becomes read-only. The CPU cannot write or erase any memory content in this mode.

Connection Interfaces and Usage Details

You will find a 40-pin edge connector at the bottom of this module. Insert this connector directly into the dedicated memory slot on the S5-135U CPU. Align the module with the guide rails on the CPU front panel. Press firmly until the latch engages securely. The Siemens 6ES5375-1LA71 Memory Module requires no external wiring or power supply. The CPU provides all necessary voltage and data signals through the connector. A label area allows marking the module with program name and version. The mechanical write-protect switch sits on the top edge of the module. Slide it left for normal read/write operation. Slide it right to prevent any modification to stored data.

Installation and Replacement Steps

You power off the PLC system before inserting this memory module. First, locate the dedicated memory slot on the S5-135U CPU front panel. Then, align the module with the plastic guide rails carefully. Push the module downward until the latch locks automatically. The Siemens 6ES5375-1LA71 Memory Module does not require battery backup for data retention. To remove, press the release latch and pull the module upward. Use the STEP 5 software to write programs directly to the memory module. The CPU can program the EEPROM without removing it from the system. The CPU automatically detects the module at power-up. Verify successful detection by checking the system status LEDs. Keep the write-protect switch in PROTECT mode for normal operation.