S7 Pointers - Why doesnt this work?

STL??? said:

Hi Folks,
I have wrote a FC which returns Dint Data based on a Station number (Byte)

ie
St1 DBD0
St2 DBD4
etc
St14 DBD52

First i wrote the following which doesn't work:

L #ByStationNo

+ -1 

L 4

*D 

SLD 3 

T #tDwOffset

 

LAR1 P##tDwOffset 

Here you load the pointer to your calculations address instead for the calculation itself. If you skip P# it should be OK.

You can activate monitoring of AR1 and see the actual adresses. 

 

OPN #DbTargets

L DBD [AR1,P#0.0] 

T #DiTarget

 

Ar1 value was L0.0 so i changed approach to this:

L #ByStationNo

+ -1 

L 4

*D 

SLD 3 

LAR1 

 

OPN #DbTargets

L DBD [AR1,P#0.0]

T #DiTarget

Which works fine - Could someone enlighten me to the problem with the first program?

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