General

The PLC memory supports:

  • located application data,

  • unlocated application data,

  • the program: task descriptors and executable code, constant words, initial values and configuration of inputs/outputs.

Structure without Memory Extension Card

The data and program are supported by the internal RAM of the processor module.

The following diagram describes the memory structure.

Structure with Memory Extension Card

The data is supported by the internal RAM of the processor module.

The program is supported by the extension memory card.

The following diagram describes the memory structure.

Memory Backup

The internal RAM is backed up by a Ni-Cad battery supported by the processor module.

The RAM memory cards are backed up by a Ni-Cad battery.

Specificities of Memory Cards

Three types of memory card are offered:

  • application: these cards contain the application program. The cards offered use either RAM or Flash EPROM technology

  • application + file storage: in addition to the program, these cards also contain a zone which can be used to backup/restore data using the program. The cards on offer use either RAM or Flash EPROM technology

  • file storage: these cards can be used to backup/restore data using the program. These cards use SRAM technology.

The following diagram describes the memory structure with an application and file storage card.

NOTE: On processors with 2 memory card slots, the lower slot is reserved for the file storage function.