1.Issue:

What does the Control Expert message: "XX% memory reserved for online changes of unlocated variables is used” mean?

2. Product Line:

EcoStruxure Control Expert, Unity Pro


3. Resolution:

(Where "XX" is a value that depends on memory usage)

This message means that the XX% of the data memory (in Kbytes) that has been assigned for the management of the data memory is being used.

This message will appear if the feature named Create New data block on line has not been checked and if unlocated variables are created or modified.

The Create New data block on line feature allows adding or modifying variables without limitation of the memory block. When this option is checked the allocation of unlocated variables can be done online and it is not necessary to Rebuild all Project. Also when this option is checked, when the data memory area approached maximum usage a new area would be allocated without user intervention.

To find the option the next path must be followed:

Tools -> Project Settings -> Build Settings -> Create New data block on line



This function can be activated with an online change, while deactivating this function or changing the size of the free data memory  requires a Rebuild All Project (offline).

If the option Create New data block on line is not selected , every time unlocated variables are created or modified they are added to the memory block of the PLC, and when the memory allocated is full then it is not possible to perform additional on-line modifications. In this case a Rebuild All Project will be required.

In earlier versions of Unity Pro a limited amount of free memory was available which was allocated to the declaration of new variables. Once the memory is full, the user is unable to create any more variables while online. It would be needed to go offline rebuild and reload the application. As Unity evolved the developers addressed this online change limitation by adding the selection Create New data Block on line.

Released for:Schneider Electric UK