Siemens 6ES5376-0AA11 – Memory Module for SIMATIC S5 Program Expansion

The Siemens 6ES5376-0AA11 increases program storage capacity for S5 central processing units. This memory module measures 250 mm in depth and 25 mm in width. It fits standard SIMATIC S5 rack slots without any modifications. The unit weighs 0.28 kg, making installation quick and straightforward.

Storage Capacity and Memory Technology

This memory module provides 16 kB of additional RAM for user program storage. The Siemens 6ES5376-0AA11 uses battery-backed CMOS technology for data retention. A replaceable lithium battery preserves memory content for up to one year. The module stores program blocks, data blocks, and system parameters reliably. It supports both read and write operations from the host CPU.

Internal Architecture and Component Layout

The module contains two separate circuit boards inside its plastic housing. One board holds the RAM chips, while the other manages memory control logic. The Siemens 6ES5376-0AA11 includes address decoding circuits for proper memory mapping. A 48-pin edge connector interfaces with the S5 backplane for data access. The module stores 33 µF of capacitance for power supply filtering only.

Battery Monitoring and Data Integrity

The Siemens 6ES5376-0AA11 includes a low-battery detection circuit on its main board. This circuit triggers a red LED when battery voltage drops below safe levels. A write-protect jumper prevents accidental overwriting of critical program data. The module automatically switches to battery power when backplane voltage drops. It retains data even when you remove it from the rack.

Power Requirements and Environmental Tolerance

The Siemens 6ES5376-0AA11 draws 80 mA at 5V DC from the backplane supply. It draws only 5 µA from the backup battery during power-off conditions. The module operates reliably from 0°C to 60°C ambient temperature. It tolerates humidity levels up to 95 percent without any condensation issues. The unit withstands vibration up to 2g from 10 to 500 Hz.

Below is a complete summary of its technical specifications.

The Siemens 6ES5376-0AA11 replaces older memory modules in S5-115U and S5-135U systems. You do not need any special programmer or eraser for this module. This unit also supports in-system programming without removing it from the rack. Consequently, it provides flexible program expansion for complex automation tasks.