How to reset or Move "null Value" in String Datatype ?

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Split from Defining of string data type.

ANSHUMAN_SINGH

How to reset or Move "null Value" in  String Datatype with Simatic manager For S7-317 2pn/dp PLC.

Assuming a string is defined in DB1 from DBB0 onwards and using the STL language

 Quick and dirty ->

L 0
T DB1.DBB1

Thanks for your Response,

I have tried the above in STL but i didn't get the desired result. I am using Simatic Manager with PLC s7-317 Pn/Dp.
My requirement is to reset String Data Type to initial Value.

Hello.

ANSHUMAN_SINGH

Thanks for your Response,

I have tried the above in STL but i didn't get the desired result. I am using Simatic Manager with PLC s7-317 Pn/Dp.
My requirement is to reset String Data Type to initial Value.

Showing a screen capture of how the string is declared would be helpful to customizing the response.

The method I spoke of does work; just not in the way you expect it.

The 2nd byte in a string indicates how much of the string is filled. The following bytes that stores the ASCII characters is only valid if the 2nd byte says it is.

For that reason quick-and-dirty. The PLC ignores the characters and over-write it. But for human eye the string looks chaotic when seeing the characters left over.

If that is not good enough for you to have the characters in the string be 'invalid' - use block move or fill to make everything except the 1st byte 16#0.

Bye.

Sir,

I have attached a screenshot for reference. My DB no is 800,we use this DB for report generation. when we start 1st Cycle we write the Cyle name for report reference(through HMI). let say 1st Cycle name is "Batch_01" for 1st address in screenshots "MV01_PHT_Batch_Cycle" .

Once 1st cycle is over and we start  2nd Cycle then last cycle batch name appears in I/O field. due to which there is an error in the reports.

My requirement is to reset the I/o field or the address so that it should no show the last written value in that address.   

I can use a bool address to reset those address after a cycle over. So, how can i do that?

Thanks in advance.