Siemens 6ES5340-5AB21 SIMATIC S5 340 RAM Memory Module

Features

-16K-instruction memory capacity
-32 KB CMOS RAM
-Rugged-format construction
-Battery-backed data retention
-Hardware-configurable addressing
-Byte- and word-mode operation
-Double-height Eurocard format
-Two 48-pin base connectors

Product Overview

The Siemens 6ES5340-5AB21 is a SIMATIC S5 Series 340 CMOS RAM memory module developed for user-program storage in compatible S5 controllers. This rugged-format module provides capacity for 16K instructions, equivalent to 32 KB of memory. Program data is retained through the backup-battery circuit of the host power supply when the main logic supply is interrupted. The board also uses hardware links to establish its operating mode and address range. Correct installation therefore depends on more than the physical connector: the controller type, byte or word operating mode, memory map and existing link arrangement must all be checked.

Technical Specifications

Benefits

-Provides twice the memory capacity of the 6ES5340-5AB11
-Supports writable program storage
-Maintains the original SIMATIC S5 hardware architecture
-Allows controller-specific memory mapping
-Retains program data through the host backup circuit
-Supports structured maintenance and commissioning work

Application Areas
SIMATIC S5 Program-Memory Expansion--The 6ES5340-5AB21 provides 32 KB of RAM for compatible S5 systems requiring space for up to 16K instructions. It is suitable for control programs that exceed the capacity of the 16 KB 6ES5340-5AB11 while remaining within the host controller’s available memory range.

Automated Machinery--The module can store sequencing, interlocking, timing and actuator-control logic in established industrial machinery. Applications may include production equipment, material-handling systems, packaging lines and machine-control panels built around the SIMATIC S5 platform.

Process-Control Installations--In compatible plant-control systems, the module may hold programs for operating sequences, equipment permissives, alarm processing and process coordination. Engineers must preserve the original RAM and EPROM address allocation when changing the board.

Commissioning and Engineering Systems--Its read/write RAM structure supports program loading and controlled logic changes during commissioning. The board is also relevant to engineering test systems used to reproduce or diagnose an existing S5 hardware configuration.

Frequently Asked Questions

1. What is the capacity of the 6ES5340-5AB21?
The module stores up to 16K instructions, corresponding to 32 KB. The instruction figure and byte figure describe the same physical capacity in different addressing units; they should not be added together.

2. How does the 6ES5340-5AB21 differ from the 6ES5340-5AB11?
The 5AB21 provides 16K instructions or 32 KB, while the 5AB11 provides 8K instructions or 16 KB. Their documented current requirements also differ: the 5AB21 draws up to 0.80 A from the logic supply and up to 60 µA from the backup supply.

3. Why must the address-link settings be checked?
The links establish the board’s operating mode and memory range. Incorrect settings can produce an address conflict, overlap RAM and EPROM areas, or place the module outside the controller’s permitted user-memory range. Record the original links before removing the installed board.