Siemens 6ES5 340-3KB42 SIMATIC S5 64 KB RAM Memory Module

Features

-64 KiB CMOS RAM
-32,768-instruction capacity
-Compact Series 340 construction
-Battery-backed data retention
-External backup-voltage connection
-Hardware-configurable memory addressing

Product Overview

The Siemens 6ES5 340-3KB42 is a compact-format Series 340 memory module for SIMATIC S5 programmable controller systems. It provides CMOS RAM for storing PLC user programs and application data, with a documented capacity of 32 × 2¹⁰ instructions or 64 × 2¹⁰ bytes. The module uses battery-backed memory. Under normal operation, the RAM is supplied through the controller system. When the main supply is unavailable, an internal or external backup arrangement can preserve the stored program. The module also provides connections for an external DC backup source during battery maintenance or controlled module handling. Addressing is configured through hardware settings on the module. The correct start address, end address, operating mode and installed memory arrangement must therefore be documented before replacing or moving the module.

Technical Specifications

Benefits

-Expands available user-program memory
-Provides writable PLC program storage
-Supports controlled battery maintenance
-Preserves established S5 memory architecture
-Enables exact address-map configuration
-Supports existing S5 controller installations

Application Areas
SIMATIC S5 User-Memory Expansion--The 6ES5 340-3KB42 expands the memory available for user programs, data blocks and machine-control logic. The usable capacity depends on the address range supported by the installed CPU and the configuration of other memory modules.

S5-130W Controller Systems--Siemens identifies the Series 340 module for use in suitable S5-130W configurations. In these systems, the module operates with byte-addressed memory settings that must correspond to the controller’s documented memory map.

Machine and Process-Control Program Storage--The RAM module can store PLC logic for production equipment, sequence control, interlocking and process automation. Reliable retention during a power interruption depends on the condition and configuration of the backup supply.

Frequently Asked Questions

1. Will the PLC program remain in memory when the main power is switched off?
The module uses CMOS RAM, so data retention depends on the backup supply. The controller power-supply battery, the module’s battery arrangement or an external backup source must remain functional. The program should always be archived before battery or power-supply work.

2. Can the module be moved between different SIMATIC S5 controllers without changing its settings?
Not automatically. S5-130W and S5-150A/K systems use byte-oriented addressing, while S5-150S/U systems use instruction-oriented addressing. The module’s operating mode, start address and end address must agree with the destination controller’s memory map.

3. What should be recorded before removing an installed module?
Archive the PLC program and record the module slot, jumper positions, X4 coding-socket settings, configured address range, CPU model and arrangement of adjacent memory modules. Controller power must be switched off before removal.