Why move global data variable to temp?

This has arisen while looking at another issue. I've found that a value from a HMI is written to a DB. Within one function they've taken that DB variable integer, written it to a temporary variable integer, then used that within the function. Why? The value isn't processed in any way that changes it, so why write it to the temp in the first place?

Is there the possibility that another DB is open during the access of the temp variable? Accessing DBx.DBWy will result in the currently open DB being DBx

L D[AR2 said:

Is there the possibility that another DB is open during the access of the temp variable? Accessing DBx.DBWy will result in the currently open DB being DBx

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Don't understand any part of that question.

Wilso said:

Don't understand any part of that question.

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If you want use any value for one DB you need to use
OPN DBxxx.
If you need other data from other DB, then you need to open other DB.
In STL you could only one time operate 2 DBs(shar DB and IDB), which you see as L DBBxxx or L DIBxxx.

So it's better to first copy these value which you will need to the Temp at begining of the block, if any value you would like to change then copy back to DB at the end of block.