What's the mean , L D [AR1,P#2.0]

fritz

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Since "Address" is declared as an INparameter of type Pointer for a Function,it is actually the so called "V" memory area (Local data of the calling block) to which the access take place (the Pointer values are stored in "invisible" TEMP variables of the Block from which you call your Function).
So I guess you would have to call it "VD" even though this does NOT exist as a direct instruction.
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fritz

Hello Juergen

it must be V memory in thiscase which is accesss toa Pointer of Type IN, OUT or IN_OUT in anFC (which iswhat Mudong's questions and the example inEntry ID:5498301refer too).
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I do use similar approach, this is my piece of code:

L P##RP1 // pointer: kje je alociran zacetek (bit RP1) dinamicno ?
LAR1 // Load Address Register 1 from ACCU 1
L DID [AR1,P#8.0] // FPx nalozi double word 64 bitov naprej od pointerja
L L#-1 // negiraj
XOD // /FPx negiraj cel double word
L DID [AR1,P#0.0] // RPx nalozi double word na začetku
AD // (RPx AND /FPx) and double word
TDID [AR1,P#16.0] // Px shrani 128 bitov naprej od pointerja

RP1 is the one bit allocated in my FB (static variable).
First line checks the adress where this bit is allocated.
Third line loads a double word at address thatis allocated 64bits bellow RP1,4-th and 5-th line negates this double word.
6-th line loaads a double word whereRP1 begins, and finally makes word operation AND with that negated word.
7-th line stores the result in a double word 128bits bellow RP1
Practicaly makes this:

Px=RPx AND not(FPx) ; (x is number ofbit 1 to 64)instead of copying statements for 64 times.

Px,Rx,FPx are all declared as bits, thatI use in program

Itis a way to use word processingin instance data block(function block), and all variables are dynamicaly addressed, so even if the block is chnaged like adding new variables before RP1this code would always findwhere RP1 bitis and all subsequent bits.

I hope you I gave you and idea whatthis code is might used for.

I would like to join this discussion because I have very similar problem concerning the V-area memory.

I have implemented the function FC1 with one IN parameter (TEST as POINTER) like this:

L     P##TEST
LAR1
L     W [AR1,P#0.0]

I have also shared DB1 with for example two WORD's. Now in the OB1 I have :

call FC1

TEST := DB1.DBW2

When I debugging these example program step by step, I notice that the parameter is pass to the function by V21.0 (V21.0 is in the AR1 register just after LAR1 instruction done).

Question is : why we have in ACCU1 just after next instruction (L W [AR1,P#0.0]) numer of DB instead value of second WORD from DB ?

After all, please notice that I pass DB1.DBW2 instead of separate DB1, why the loaded ACCU1 in these function will be set on numer of DB instead value of the DBW2 ?

If for example write next instructions in FC1 like this:

T #TEMP

OPN DB[#TEMP]

 and this is still understandable, but next instructions I publish below are completely not understandable for me, please help me understand it :

L D[AR1, P#2.0]

A D DW#16#7FFF8

LAR1

L DBW[AR1, P#0.0]

I have done lot of test and I can write similar codes based on the pointers (for getting values from specific word from specific DB), but I can not understand first of two instructions of above code (meaning of the instructions of course is understand but I can not understand why we should do it this way).

Effect of this code is getting WORD from DB1.DBW2. This example I have met during analize one of real industry object. Please help me understand it!