Siemens 6ES5375-0LA41 Memory Sub Module

This sub module adds user program storage capacity to your S5 processor. The Siemens 6ES5375-0LA41 plugs directly into the memory slot on compatible CPU boards. It measures 85 mm in width and 55 mm in height. This unit weighs approximately 38 grams for lightweight integration.

Technical Specifications Table

Parameter	Value
Product Model	Siemens 6ES5375-0LA41
Category	Memory Sub Module / RAM Expansion
Memory Technology	Static RAM (SRAM)
Storage Capacity	32 KB (32768 bytes)
Memory Width	8-bit parallel interface
Dimensions (W x H x D)	85 mm x 55 mm x 12 mm
Weight	38 g
Connection Type	1 x 40-pin dual-in-line male header
Internal Components	8 x SRAM chips, 1 x lithium battery
Energy Storage	1 x 3.6 V lithium cell (non-rechargeable)
Data Retention Time	Approximately 1 year with fresh battery
Access Time	120 ns maximum
Power Consumption	15 µA standby (battery mode)

Internal Design and Battery Backup System

This memory sub module contains eight independent SRAM chips arranged on one board. A replaceable 3.6 V lithium battery preserves all data during main power loss. The Siemens 6ES5375-0LA41 draws negligible current from the battery in standby mode. The SRAM chips retain stored programs for approximately one year with a fresh cell. This design prevents program loss during extended maintenance shutdowns. The battery only activates when the PLC powers down completely.

Installation and Compatibility Guide

First, power down your SIMATIC S5 PLC completely before handling this module. Next, locate the empty memory sub module slot on your CPU board. Then, align the 40 gold-plated pins carefully with the motherboard socket. Press the module downward until it seats flush against the connector. The CPU automatically detects the additional 32 KB of memory on startup. This sub module works with S5 CPUs 100U, 103U, 115U, and 135U models. Always replace the lithium battery when the low voltage indicator lights up.