Siemens 6ES5-102-8MA02 4KBYTE Memory CPU Module

Siemens 6ES5-102-8MA02 is a SIMATIC S5 memory submodule designed for the S5-100U CPU 102, delivering 4KBytes of RAM to the CPU to expand working memory for runtime data and program variables without replacing the existing processor card. This 4K RAM submodule is commonly listed as a memory expansion for the S5-100U family and is compatible with CPU 102 models within the 6ES5 series. Some documentation describes the CPU memory in terms of RAM statements, with references noting up to 2048 RAM statements supported by this memory architecture. As part of the legacy SIMATIC S5 line, the 6ES5-102-8MA02 is installed to extend memory while preserving the existing program logic, offering a straightforward upgrade path for older control systems that require more memory headroom without a full hardware replacement.