Hi folks,

I have DB named Db 14. Which contains TOD format array table [0..600] length.

So I have initial value starting at Db14.dbw0.

When I give some trigger, I want to shift and rotate the value to next slot of array i.e db14.dbw2. like wise simultaneously to rotate till end of the DB 14

Can you please anyone help on this requirement to figure it out

Thanks in advance

Regards

Singaravelu S

HI Ssingaravelu

I don't quite understand what you want to do, you want to shift inside the array, to output values?, to input values?, or move the values from one dbw to another dbw??

There are many ways to do these operations, take a look at the "move" function, at the output of this function put the address, for example "DB14.DBW[x]" and in the x you indicate where you want to write or read the values.....

Regards,

G.iwan

Hi,

I want to shift within the DB. Mycase DB14.

Structure was Array and format was TOD.

There are 30 addresses namely

Starting from DB14.DBD0 ...

I want to shift all the DBD address values to its next address when I give only one trigger

If the type of data in the array is declared as a TOD (32 bit), the shift word by word will destroy all the data.

If think that you need somthing like the following code:

// Declaration
data_array : Array[0..599] OF TOD;

// Array data shift
IF x_trigger_condition THEN
  FOR i := 599 to 1 BY -1 DO
    data_array[i] := data_Array[i - 1];
  END_FOR;
END_IF;

The most efficient way is to keep the DB as it is an move the reading pointer / marker to  the next position. The link given by Towome would work well for this idea.

Unless there is some good reason you wish to shift data. What is confusing is that you also mention 'rotating'. Can you clear up what you need to do. Is the TOD information in the DB replaced by something else or is repeatedly read out? The more detail you give the more exact the volunteers' answers can be.

The concept stays very similar if data needs to be replaced by new data. The data in the DB stays in the position where they are. There is a read pointer and write pointer that moves as the data is retrieved or replaced. There are standard libraries in Step7 Classic that allows buffer usages. "add to table" and "FIFO" may be useful search words - if my memory is serves me well.

Mention also if you have access to SCL and if you are able to use it. Mention also if you feel comfortable with coding in STL.