Why am I getting error 85 from 'scan from string' VI?

Question

Data is in CSV format from an Excel spreadsheet. It may be an empty string but I compare the data to an empty string and, if is empty, then I input  the string constant '0' to the 'Scan from String' VI. I'm using 3 probes to try to debug this.
The 1st probe is at the output of an 'Index Array' VI which extracts the element of interest from the array loaded from the spreadsheet file. The probe declares it's type as 'string' and the probe content is blank. I assumed that this means 'empty string'.
The second probe is at the output of an 'Equal' VI which compares the data described above with the empty string constant "". The result is False. Why is this? How do I tell what the CSV data is? If the probe is blank can it be a Null character or NaN or is it interpretted as a blank string? The Excel file has all fields defined as 'text.
The third probe is also blank.
When the data is interpretted by the 'Scan from String' VI it fails. I also have the default pin wired to a double constant  with a value of o. Shouldn't this be used by the VI in the event the VI can't interpret the string passed to it? 
Thanks for any help,
Frank   

Answer 1

fr@nk wrote:
The second probe is at the output of an 'Equal' VI which compares the data described above with the empty string constant "". The result is False. Why is this? How do I tell what the CSV data is? If the probe is blank can it be a Null character or NaN or is it interpretted as a blank string? The Excel file has all fields defined as 'text.
Yes, it can be a Null character. NaN is something else. To really see what's there you can place an indicator and then change the display mode of the string indicator to Hex Display Mode.
You have not indicated what your format string is. Why don't you upload your code along with your data. Just out of curiosity, what are you using to read the file? Are you using Read From Spreadsheet File?