s7200 Microwin Indirect addressing

jetuaime81 · Dec 16, 2011

Hi,

I would like to know something about indirect addressing.

In the attached picture the value in VW104 is 1100. So, I need to access VB1100 and move its value to say VB110.

Is this possible and can someone show how it can be done.

Thanks and regards,
Irah

iant · Dec 16, 2011

Sorry but this is not indirect addressing it is a maths formula
-in order
VW104 = vw102 - 1
then
VW104 = vw104 x 5
then
VW104 = vw104 + 1100

SO if vw102 was 6
the result of your eqation would be VW104 = 1125

1100 is an integer
so in another rung create a move statement MOV 1100 to vw110

then replace the 1100 in your existing program with vw110

jetuaime81 · Dec 19, 2011

No no...you are not getting the question.the thing i showed is simple maths i know.but suppose the integer value is say 'X', then in the next rung I need to access VB'X'

suppose VW104 is 1100.I need to access the data in VB or VW1100 memory area.How can this be done.

I read something about & , * and accumulator (AC0, AC1 etc) operations in microwin. Can someone explain if I can achieve what im looking for with these..

Thanks

manmeetvirdi · Dec 19, 2011

S7 200 pointer

Hi,
Check this

Code:

LD     SM0.0             //always ON
MOVD   &VB0, AC2        //point AC2 to starting address of VW10
FOR    VW100, 0, VW104   //number of loops are equal to value in VW104, starting from 0
+D     1, AC2            /increment pointer AC2 so that it now points to next address
NEXT                     // GOback
//at the end of loop AC2 points to address which equal to value in VW104, if VW104 is 1100 then AC2 now points to VB1100
MOVW *AC1, VW112   //move the value in VB1100 to VW112

Note this is untested but must get you started on this.

jetuaime81 · Dec 20, 2011

Thanks Manmeetvirdi,

I think thats what im looking for. Will look into it. Thanks

iant · Dec 20, 2011

ypour first example is missing a loop back
isn't it.

s7200 Microwin Indirect addressing

jetuaime81

Member

iant

Lifetime Supporting Member + Moderator

jetuaime81

Member

manmeetvirdi

Member

jetuaime81

Member

iant

Lifetime Supporting Member + Moderator

Similar Topics