The D4-RAM-1 CMOS RAM memory cartridge with a built-in lithium battery provides 7.5K of program storage for AutomationDirect DirectLOGIC D4 PLCs. This battery-backed RAM preserves memory contents when power is removed, enabling retention of the user program between power cycles. The part is a retired AutomationDirect item (retired May 2016) and is no longer available from the supplier; AutomationDirect recommends D4-EE-2 as a replacement. Key specs include a 7.5K program capacity and a lithium-backed CMOS RAM memory cartridge whose memory can be cleared electrically, reflecting its retention design for legacy D4 systems.
