You do not have to format the data in a datalog file. However, when you write or read datalog files, you must specify the data type. For example, if you acquire a temperature reading with the time and date the temperature was recorded, you write the data to a datalog file and specify the data as a cluster of one number and two strings.
If you read a file that includes a temperature reading with the time and date the temperature was recorded, you specify that you want to read a cluster of one number and two strings.
The data type of each record in the datalog file can be of any type. However, the data type varies depending on how you logged the data to the datalog file.
For a datalog file you created using the Write Datalog function, the data type matches the data LabVIEW wrote to the datalog file.
For a datalog file you created using front panel data logging, the data type is a cluster of two clusters. The first cluster contains a time stamp, and the second cluster contains the front panel data. The time stamp includes a 32-bit unsigned integer that represents seconds and a 16-bit unsigned integer that represents milliseconds elapsed from LabVIEW system time. The front panel data cluster contains the data types that correspond to all front panel controls and indicators in their respective tabbing order.