Which PLC are you using?  When you looked at the STRING & CHAR instructions available for your PLC while your SCL block is open, what block seemed most fitting?  The MID(..) might do what you want. 

Also, there are open source String handling blocks available, both from Siemens in their LGF and from OSCAT.de.  Perhaps you can solve your problem using a tested and supported open source instruction. 

AutoGen_986302

In TIA Portal we can access any character from string just with following statement:

Char_Variable := String_Variable[Int_Position];

This works well. 

How to access a character from any string located in string array?

Char_Variable := String_Array[String_No][Int_Position];

Doesn't work,

Char_Variable := String_Array[String_No,Int_Position];

Doesn't work either.

Right now the only way I see is to copy string into local variable, and then access single character from temporary string. But this way is waste of memory, and cpu time.

vaibhav1993

 I think we can also use string to char function and then can access byte by byte.

This do not meet the requirement - no copy. 

The REF_TO and REF solution above is for S7-1500 only.

The following should work for s7-1200 PLCs.  If the string array is passed into a block (FB/FC), it should be passed as an "InOut" parameter.

In block of LAD logic, right-click on a network (where you want to access a character within a string within an array of strings) and select "Insert SCL network"

In that network, you only need this line of logic (mostly using the OP tag names):

SCL
"TempDB".Char_Variable := STRING_TO_CHAR(MID(IN := "TempDB".String_Array[#String_No], L := 1, P := #Int_Position));

However, if you want to test it, you can try it like this:

"TempDB".Char_Variable should contain the 5th character in the sample string, which is 'E' 

Unless this is called many different times in the same PLC scan, it is probably best to create an FC to capture the single character within the string array.

vaibhav1993

 I think we can also use string to char function and then can access byte by byte.

 Vaibhav