Siemens 6ES5372-0AA61 | SIMATIC S5 Memory Submodule

The Siemens 6ES5372-0AA61 expands the program memory capacity of SIMATIC S5 controllers. This pluggable submodule fits directly into compatible CPU units like the 115U and 135U. It provides additional 4 KB of RAM storage for user program extensions. You can install this module without any soldering or special tools. Consequently, you can upgrade your PLC’s memory capacity in minutes.

Technical Specifications Overview

Parameter	Detailed Specification
Model	Siemens 6ES5372-0AA61
Category	SIMATIC S5 Memory Submodule (RAM Expansion)
Memory Type	CMOS RAM (static)
Storage Capacity	4 KB (additional)
Data Retention	Requires backup battery on CPU module
Access Time	120 ns (typical)
Operating Voltage	5V DC (from CPU submodule slot)
Power Consumption	15 mA (operational) / 2 µA (data retention)
Compatibility	S5-115U, S5-135U, S5-150U CPUs
Dimensions (approx.)	45 mm x 28 mm x 10 mm
Weight	0.02 kg (20 grams)
Connector Type	40-pin gold-plated edge connector
Number of Components	Single submodule (no external wiring needed)
Operating Temperature	0°C to 60°C

Functional Features and Memory Expansion

The Siemens 6ES5372-0AA61 plugs into the dedicated submodule slot inside the CPU housing. You can combine multiple submodules to achieve larger total memory capacity. The CMOS RAM technology provides fast read and write access for time-critical logic. Furthermore, the module consumes minimal power during normal operation.

This submodule retains all data only while the CPU’s backup battery supplies voltage. You will lose stored programs if the battery fails or discharges completely. Additionally, the module supports both program blocks (OB, PB, SB) and data blocks (DB). The CPU automatically detects the additional memory upon power-up.

Installation and Handling Guidelines

First, power down your SIMATIC S5 completely and remove the CPU module. Next, open the small access cover on the top or side of the CPU casing. Then, align the Siemens 6ES5372-0AA61 correctly with the internal guide rails. Finally, press firmly until the connector seats fully into the socket.

You must observe proper anti-static precautions when handling this submodule. The gold-plated contacts are sensitive to skin oils and contamination. Always store spare submodules in anti-static bags for protection. Furthermore, do not force the submodule if you feel resistance during insertion.

This memory submodule works perfectly for expanding legacy S5 programs. It supports additional ladder logic steps, function blocks, and data tables. You can install it alongside other memory types like EPROM submodules. The Siemens 6ES5372-0AA61 gives older CPUs a new life for larger applications.