About the D4-EE-2
The Automation Direct Facts Engineering Koyo D4-EE-2 is an EEPROM memory cartridge. A member of the DirectLogic 405 series, this device interacts with central processing unit (CPU) modules from the same series family. Programmable logic controller CPUs such as D4-440 and D4-450 do not have any integrated system memory and require external memory cartridges. Cartridges like D4-EE-2 provide D4-440 or higher systems with needed system memory.
D4-EE-2 provides EEPROM memory storage space to logic controllers. This cartridge has 15.5K of available memory to store system programs and data. EEPROM memory can be read an infinite amount of times and can retain all stored memory indefinitely. No cartridge battery is required as power is not needed to maintain the saved memory. The cartridge does have a finite number of times it can be written to, with a life cycle of less than 10,000 writes. The D4-EE-2 cartridge has an electrical memory-clear method. To install into a base, the cartridge fits into the designated memory card slot on the back of the CPU module. After installation, the device is ready to be written and read from.
Following all outlined storage and installation parameters will prevent the cartridge from being damaged. To prolong the life of D4-EE-2, transitional logic, like one-shot, should be used with the device. This allows all data to be written once rather than with each CPU scan. Installation graphics and directions are available in the device user manual and datasheet.