Retentive memory (DB's)

Hi bilro,

Readback function works only with block that support S7_read_back parameter: DB doesn't support this parameter and read back function doesn't updaate your OffLine DBs.

If you want initialize the OnLine DB with your own values, you have to set "Actual Value" in OffLine DB and i't will be vritten when you download DB.

Each time you need change the values and need store them, then only way is save OnLine DBs overwriting OffLine DBs.

If you want some more automatic values update you need write a function to store them in different position, p.e. on windows files (ascii or binary).
You could use a DB word as well as coordinator: p.e. writing0 by download, winCC detect change and write all values andcoordinator word withNON 0 value.

I hope can help you a lil
Regards

Hi bilro,

CBo is right. Read back is not allowed in global DB's.

A solution for your problem is create your WinCC tags in FB parameter instead of DB with S7_read_back=true.

The other option is periodically copy online DB to offline and while downloading CFC's uncheck "Include user DB's" option.

Regards