What This Is
The Siemens 6ES7791-0DP00-0XA0 is a memory expansion module for the PG 740 and PG 760 programming devices, adding 16 MB of storage capacity. This is a field-upgradeable option that slots into the device to increase local memory for project files, firmware archives, or backup images.
This memory expansion is specific to the PG 740 and PG 760 P-series programming devices. It is not a general-purpose SIMATIC memory card or MMC — it interfaces with the internal expansion slot on those units. If you are maintaining a fleet of legacy Siemens programmers for plant-floor support, this is the correct part to keep them running. For newer PG models (PG 741, PG 761, or PG 2000 series), a different memory module is required.