Retentivity Configuration

When designing a PLC application, it is important for the PLC user to understand the different types of memory in the PLC. Three types of memory are used by the Mikrodev PLC; RAM, SRAM and FLASH memory.

SRAM memory can be configured by the PLC user as either retentive memory. SRAM is powered by internal battery when PLC external power is off.

Retentive memory is memory that is configured by the user to maintain values through a power reset. Non--retentive memory is memory that is configured by the PLC user to clear data after a power reset.

The default behaviour of the blocks in Mikrodev PLC is non-retentive. You need to select "Retentive" option to make the block use retentive memory. Note: You can add maximum 256 retentive blocks on the device. You can check total retentive block count on the project using Mikrodiagram Tools>Show Project Info.