Siemens 6ES5340-3KB42 Memory Module

The Siemens 6ES5340-3KB42 Memory Module provides external program storage for SIMATIC S5-135U systems. This module uses EPROM technology for non-volatile data retention. You will find it in large-scale automation projects requiring backup of complex logic. It stores user programs and configuration parameters safely without battery backup. Therefore, this unit eliminates the need for periodic battery replacement in memory areas.

The Siemens 6ES5340-3KB42 Memory Module measures 230 mm in height and 48 mm in width. Its depth reaches 180 mm for standard rack mounting. The unit weighs approximately 0.35 kilograms. It contains eight EPROM chips with a total capacity of 512 KB. No internal battery maintains data in this module. Additionally, you get one write-protect cover for data security.

Key Technical Specifications

Internal Architecture and Energy Storage

The Siemens 6ES5340-3KB42 Memory Module stores absolutely no electrical energy internally. It contains no capacitors or batteries at all. Eight EPROM chips provide 64 KB each for program and data storage. Each chip uses a quartz window for UV erasure when necessary. A small PCB traces all 40 pins from the edge connector to the EPROMs. The module uses parallel access for fast read operations during PLC execution. A mechanical cover prevents accidental data exposure to UV light. You must remove this cover only when erasing the EPROMs. Each EPROM chip sits in a socket for easy replacement if needed.

Connection Interfaces and Usage Details

You will find a 40-pin edge connector at the bottom of this module. Insert this connector directly into the dedicated memory slot on the S5-135U CPU. Align the module with the guide rails on the CPU front panel. Press firmly until the latch engages securely. The Siemens 6ES5340-3KB42 Memory Module requires no external wiring or power supply. The CPU provides all necessary voltage and data signals through the connector. A label area allows marking the module with program name and version. The mechanical write-protect cover sits over the EPROM quartz windows. Keep this cover closed during normal operation to prevent data corruption. Remove the cover only when exposing the chips to UV light for erasure.

Installation and Replacement Steps

You power off the PLC system before inserting this memory module. First, locate the dedicated memory slot on the S5-135U CPU front panel. Then, align the module with the plastic guide rails carefully. Push the module downward until the latch locks automatically. The Siemens 6ES5340-3KB42 Memory Module does not require battery backup for data retention. To remove, press the release latch and pull the module upward. Use an EPROM programmer to write programs to the module before installation. Insert each EPROM chip into its socket with correct orientation. The CPU automatically detects the module at power-up. Verify successful detection by checking the system status LEDs. Store spare modules in anti-static bags away from UV light sources.