Siemens step7 pointers

[rebetiko]

Hi every one.
I am trying to verify the following:
A DINT can be converted to a POINTER by simply shifting the double word left by 3 bits.
i want to prove that DINT 160 results in P#20.0 after a SHL3 on 160.
can some1 prove it by means of an example?
its doing my head ?
1010 0000 = 160 (DINT)
if i do a SHL3 in the above , i get 0000 0000 (?)
but if i do a SHR3 i get 0001 0100 which is 20 (for P#20.0)

so
is it a SHL3 or a SHR3 that converts DIN160 into P#20.0 ?

Many thanks 2 all

 

[wimpiesplc]

Hi every one.
I am trying to verify the following:
A DINT can be converted to a POINTER by simply shifting the double word left by 3 bits.
i want to prove that DINT 160 results in P#20.0 after a SHL3 on 160.
can some1 prove it by means of an example?
its doing my head ?
1010 0000 = 160 (DINT)
if i do a SHL3 in the above , i get 0000 0000 (?)
but if i do a SHR3 i get 0001 0100 which is 20 (for P#20.0)

so
is it a SHL3 or a SHR3 that converts DIN160 into P#20.0 ?

Many thanks 2 all

From my head. For starters, you say you use a DINT but your examples shows shifting bytes.

SLD 3 on 1010000, which is actually 2#00000000000000000000000001010000, would produce 2#00000000000000000000001010000000

 

[PLCKeef]

I think 160 is
10100000
A0 in hex

The pointer format is
XXXXXXXXXXXXXXXX.BBB

I think the 160 might already be in the correct format for
0000000000010100.000
P#20.0

Where is the 160 coming from ?

Maybe try
L 160
LAR1

the contents will then be 20.0

 

[L D[AR2P#0.0]]

As aready stated, 160 dec is P#20.0 when shown in pointer format.
The coding for converting to pointer format is as below: