Siemens 6ES5374-2FK21 Memory Card

Technical Overview

The Siemens 6ES5374-2FK21 is a memory card designed for use with SIMATIC S5 programmable logic controllers, specifically the S5-115U, S5-135U, and S5-155U models. This module provides reliable non-volatile storage for user programs, ensuring data integrity even during power outages. It utilizes FLASH EPROM technology, offering secure program retention without the need for a backup battery. This reduces maintenance complexity and enhances overall system reliability.

The card mounts directly into the CPU or memory submodule slot, making installation simple and straightforward. The module communicates with the CPU via the S5 bus. The card supports the standard STEP 5 programming language and is compatible with all major S5 programming devices.

Technical Specifications

Parameter	Specification
Manufacturer	Siemens
Model Number	6ES5374-2FK21
Product Type	Memory Card / EPROM Memory Submodule
System Compatibility	SIMATIC S5-115U, S5-135U, S5-155U
Memory Type	FLASH EPROM
Memory Capacity	8 KB
Data Retention	Non-volatile (no battery required)
Programming Language	STEP 5
Installation	Plugs into CPU or memory slot
Weight	0.02 – 0.1 kg
Dimensions	5.10 x 5.10 x 12.70 cm
Operating Temperature	0°C to +60°C
Storage Temperature	-40°C to +85°C
Certifications	CE, UL, CSA
Country of Origin	Germany

Key Features

Non-Volatile FLASH Storage – The module retains programs without a backup battery, eliminating maintenance costs.

Wide S5 Compatibility – The memory card works with S5-115U, S5-135U, and S5-155U controllers.

Plug-and-Play Installation – Users can insert the card directly into the CPU slot.

STEP 5 Program Support – The module stores standard STEP 5 user programs.

Compact Size – The small footprint fits easily into the S5 chassis.

Applications

The Siemens 6ES5374-2FK21 suits program storage, system backup, and firmware upgrades in automation systems. It is widely used in manufacturing, process control, and industrial automation for reliable program storage.