Siemens 6ES5 340-5AA11 SIMATIC S5 8K RAM Memory Module

Features

-8,192-instruction RAM capacity
-16 KiB equivalent storage
-Read/write user-program memory
-Rugged Series 340 construction
-Hardware-configurable addressing

Product Overview

The Siemens 6ES5 340-5AA11 is a Series 340 read/write RAM memory module for the SIMATIC S5 controller platform. It is identified as a rugged-format memory board with a documented capacity of 8 × 2¹⁰ instructions. The module provides 8,192 instruction locations. With two bytes allocated to each instruction-storage location, this represents 16,384 bytes, or 16 KiB, of addressable RAM capacity. Its purpose is to expand the user-program memory available to a compatible SIMATIC S5 controller. The RAM may contain program instructions, data blocks and other information used by the PLC application. Because the module uses writable RAM, program retention depends on the system’s functioning backup-power arrangement. The memory range is configured through hardware links. Siemens documentation shows that sections of the available memory can be inhibited in 2K-word or 4KB increments when the address range must be coordinated with other installed memory modules.

Technical Specifications

Benefits

-Expands available PLC program memory
-Provides writable application storage
-Supports established S5 memory layouts
-Allows unused memory ranges to be inhibited
-Supports mixed memory configurations
-Maintains exact article-number identification

Application Areas
Machine-Control Program Storage--The module can hold program instructions and data used for machine sequences, operating modes, interlocks and production control. The archived PLC program should correspond to the exact machine version.

Existing Memory-Map Restoration--The module is relevant when an electrical drawing, controller configuration or maintenance record specifies 6ES5 340-5AA11. Restoring the documented address range helps preserve the original PLC memory structure.

Mixed RAM and Program-Memory Configurations--Where several memory modules share the controller address space, portions of the 6ES5 340-5AA11 range can be inhibited through socket 71. This helps prevent overlapping ranges, but the complete memory map must be calculated before startup.

Frequently Asked Questions

1. What is the memory capacity of 6ES5 340-5AA11?
The documented capacity is 8 × 2¹⁰ instructions, equal to 8,192 instruction locations. At two bytes per instruction-storage location, this corresponds to 16 KiB.

2. What is the difference between 6ES5 340-5AA11 and 6ES5 340-5AA21?
The 6ES5 340-5AA11 is cataloged with 8K instruction capacity. The 6ES5 340-5AA21 is cataloged with 16K instruction capacity. A change between the two models can affect the memory map and should not be made without checking the CPU address range and hardware links.

3. Is the rugged module interchangeable with a compact 340 memory module?
It should not be treated as an automatic mechanical or electrical substitute. Rugged and compact versions can differ in construction, backplane arrangement, capacity and address configuration. The complete article number and controller documentation must be compared.