I am currently using LabVIEW6.1 and have little trouble with this refnum business. Configuration File VIs give refnums that are not refnums. I check this by using the comparison function "NOT A Number/Path/Refnum?" . The same thing happen when I cast a numeric to refnum using "data log file refnum" as the data type. Thanks, tc phan
Configuration File VIs give refnums that are for other Configuration File VIs only. The refnum is created by type casting a numeric. These refnums are incompatible with the File IO refnums for various other file operations.
Config File refnums are not actual file refnum to the config file but a refnum to config data in memory. You can't use it for file operation. "NAN/P/R" will always return TRUE. To test if a config file refnum is valid, use "Not a Config File Refnum.vi".