S7 Data Block Clearing/Wiping Issue

All-

Greetings, and happy Thursday.

I've got a bit of a question regarding Data Blocks in Step7. I apologize ahead of time if it is obtuse to inquire; however, I'm looking for a clean method of wiping a Data Block (DB) to it's initial state, and/or neatly setting everything to a pre-determined value after an operation.

Now, for the fun caveat. I can't use STL or SCL.

Help?

The easiest way is to have a duplicate copy of the block with its initial values in and then copy the duplicate into the working block when you wish to "reset" it using SFC20.

Nick

I've tried doing that, but I get an error each time with the following logic, and was advised I can't "BlkMov" one DB directly into another DB. Posted in STL for sake of ease of posting.

A Test1
JNB _00c
CALL "BLKMOV"
SRCBLK :=DB23
RET_VAL:="test".DB_VAR
DSTBLK :=DB22
_00c: NOP 0

It seems that your problems are in the AnyPointer department. The picture attached shows two calls to SFC20 both copying data from "Backup" to "Working". In the first call, the address are typed in explicitly whereas in the second example a UDT has been used to simplify things. An added advantage of using a UDT is that the working data and the backup data can both reside within the same DB.

Nick

That did the trick. Thanks for the help.