The 512 KB SRAM modules expand the range of the APC620 and Panel PC 700. This allows applications that do not require a fi eldbus card with integrated SRAM to store nonvolatile data in the optional SRAM module. Due to the power supply buffering integrated in the APC620 and Panel PC, Automation Runtime applications support the backup of data in the SRAM module when a power failure occurs. This module uses the buffer battery from the PC system. It is inserted directly on the PC board and doesn't require a PCI slot.