How can I create the global static variable in Vi?

[Y@sh001]

Hi 

I am trying to concatenation received String over TCP IP through sub VI. Sub Vi(DecodePakcet.vi) is call whenever the Data is available in to Queue. 

So, I would like save the concatenate string for next call of DecodePakcet.vi. I found the on Labview help Shift register is used as static variable. But I think it is work as local static variable (scope withing while loop).

I am trying to use global static variable or similar thing in Labview.
For Example.

1) TCP/IP receive 4 bytes "ABCD".

2) "ABCD" is store into Queue and en queue in another while loop.  

3) On second while loop I am calling DecodePakcet.vi.
4) DecodePakcet.vi. is take string, and concatenate received string with previous received String, if previously, there is not any string receive then it is just store for future purpose. 
5) Now another string is received over TCP/IP, which is "EFGH".

6) repeat steps from 2,3,4

The end result will be something like  "ABCDEFGH".

In reality, I am trying to decode Packet, which is received over TCP/IP.

    



   

[altenbach · Accepted solution]

If you would put the loop and  shift register into an action engine, it is no longer local to one particular loop of the caller.

[Y@sh001]

Thank you for response.  

[Y@sh001 · Accepted solution]

Thank you altenbach. I am able to conactenate string using while and Case structure, and shift register. Just for my knowledge. What is action engine, and where do I get in Labview. I just found some stuff related to AF, They show AF is store the value and perform the operation. 

[altenbach]

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Y@sh001 wrote:

 What is action engine, and where do I get in Labview. 

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Start reading here ... 😄