Siemens 6ES5374-2KH21 is a long‑form memory card for SIMATIC S5 PLCs. It contains 256 KB of Flash-EPROM storage and is a 5V‑only module designed as a removable memory cartridge for S5 systems. This Siemens spare‑part memory card replaces memory components in legacy installations, enabling retention of programs and data between power cycles. With its long design and 5V Flash‑EPROM technology, the 6ES5374-2KH21 is a compatible retrofit for older SIMATIC S5 controllers.
