ACCU 1-L and ACCU 2 - L

Hello members!

In HELP of Step7, i have next information:

jacek d

ACCUx-L is the less significand word of an ACCUx, i.e. bits from 0 to 15.

 Then, the ACCU1-H (in shift rotations) - the high significand word from 16 to 31 bits?
But what's ACCU 2- L-L then? 

Hi,

ACCU 1 and ACCU 2 are memories zone reserved where are store some values according to your program instruction.

You need to laod values into accumulators when you want to do some addition, substraction, multiplication, division, mask.

When you use Load (L) instruction, the value store into ACCU1 is transfer into ACCU2 (Value previously store into ACCU2 is lost) and value you want to load is store into ACCU1.

Wjhen you use Transfer (T) instruction value store into ACCU1 is transfer into your variable.

I don't understand what you want to do exactly. Can you explain with more details what you want to do.

You can not access to ACCU2, if you want to transfer value store into ACCU2 into your variable, you need first to use function "TAK" to swith ACCU1 and ACCU2 and then transfert with "T" instruction content of ACCU1 to your variable.

Regards.

Sapher_Jalt

But what's ACCU 2- L-L then? 

Think bytes...
H-H    H-L    L-H    L-L

Lower word, lower byte

Sapher_Jalt

Hello members!

In HELP of Step7, i have next information:

unknown user

Example 1: STL Explanation

L IW20      //Load contents of IW20 into ACCU 1-L.

L IW22      //Load contents of ACCU 1 into ACCU 2. Load contents of IW22 into ACCU 1-L.

AW            //Combine bits from ACCU 1-L with ACCU 2-L bits by AND; store result in ACCU 1-L.

T MW 8     //Transfer result to MW8.

Example 2: STL Explanation

L IW20                     //Load contents of IW20 into ACCU 1-L.

AW W#16#0FFF     //Combine bits of ACCU 1-L with bit pattern of 16-bit constant                         0000_1111_1111_1111) by AND; store result in ACCU 1-L.

JP NEXT                 //Jump to NEXT jump label if result is unequal to zero, (CC 1 = 1).

 What is ACCU1 - L and ACCU2 - L? 
We just take the content of ACCU1 and do the -1 math operation? 
The same for ACCU 2- L? 

I met it in LOOP, Bool logic operation for Word Data Type. 

 Hello,

Please read this manual like Chapter 7 and so on:

Anweisungsliste (AWL) für S7-300/400 - Siemens

Panov69

Hi,

ACCU 1 and ACCU 2 are memories zone reserved where are store some values according to your program instruction.

You need to laod values into accumulators when you want to do some addition, substraction, multiplication, division, mask.

When you use Load (L) instruction, the value store into ACCU1 is transfer into ACCU2 (Value previously store into ACCU2 is lost) and value you want to load is store into ACCU1.

Wjhen you use Transfer (T) instruction value store into ACCU1 is transfer into your variable.

I don't understand what you want to do exactly. Can you explain with more details what you want to do.

You can not access to ACCU2, if you want to transfer value store into ACCU2 into your variable, you need first to use function "TAK" to swith ACCU1 and ACCU2 and then transfert with "T" instruction content of ACCU1 to your variable.

Regards.

The full question is:

-  i have this code

L #RND (word data type)

AW

T #wShift (word data type)

.... start the loop ... during 16 cycles

go to start of the loop.

The discriptions is: In each cycle, the register i shifted ti the left by one bit and the bits 15, 13, 12 and 10, are operated by XOR. The result of the XOR is the input bit of the shift registor.

But i can't see the math of these operations - XOR and AW. What's they operates for? I think, that the descriptions doesn't match with the code.

And here i meet the ACCU 1 -L and others. 

Thank you,

Your answeres go to an extent in making me understand how the accumulator works. I will only be fully satisfied when I see it working.

Cheers!!

RenFlower

Thank you,

Your answeres go to an extent in making me understand how the accumulator works. I will only be fully satisfied when I see it working.

Cheers!!

 Dear Ren,

if you have problems we are here!!