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Search empty string in Data Table

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I have a Samba sm43-j-r22. 

I need to search in Data Table a row that has a column (of type string) with an empty value.

I have tried using the function "Data Tables Find Row" with the "Start address of value to find" with an MI operand with value equals to 0, because I think that an empty string has it first byte equals to null. But It wasn't succesful.

How can I acomplish this?

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I had to do this a few years ago and couldn't find a way to do with the string.


I finally added and extra column into the data table which was a MI and searched for it.   0 Meant that it had an empty string field  1 meant that the string field had data in it.

You'll have to make sure that when you get a new PLC you write a blank DT into it as often there is garbage in the DT which will mess with the above solution.

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