Using SFC20 to copy SDB's

I came across the following coding method which appears to use SFC20 to copy from SDB200 (the SDB used for configured connections) by specifying the source area as DW#16#89000000

Has anyone any experience of using SFC20 for this purpose ?

L P##psource
LAR1
L W#16#1002 // = S7 BYTE
T W [AR1,P#0.0]
L 2 // = Repetition 2 (bytes).
T W [AR1,P#2.0]
L 200 // = DB number 200
T W [AR1,P#4.0]
L DW#16#89000000 // = memory area (*)
T D [AR1,P#6.0]
CALL SFC 20
SRCBLK :=#pSource
RET_VAL:=MW100
DSTBLK :=#WData

*: From Hans Berger and STEP7 online help I know that the memory area is specified as
81 = inputs
82 = outputs
83 = Merkers
84 = DB
85 = IDB
86 = L-Stack
87 = Previous L-Stack

If 89 = SDB, then that is undocumented.
Could be true. I never thought of that you could poke around in the memory like that with SFC20.

well, so who is first, if 89 is sdb, what is 88?

Nice to know those little undocu things thanks LD.

I've tried using SFC20 to copy SDB122 in a 317-2DP CPU but SFC20 reports an error saying the DB is not loaded.

I came across the 89 area when wading about in the code recently posted by pethoek concerning SFB14/FB14 - it's in the library that I posted in the thread.

L D[AR2 said:

I came across the 89 area when wading about in the code recently posted by pethoek concerning SFB14/FB14 - it's in the library that I posted in the thread.

Click to expand...

Well it may be the typo which pethoek is looking for !!