How to add a timestamp to a TDMS file

[boostinallovryou]

I need to add a timestamp to my TDMS file.  Currently I am taking an array of doubles, converting them to a dynamic data type, then sending that to tdms_write.  I need to add a timestamp but I can not find a way to do that.  I have also tried taking the timestamp, converting it to a doube, U64, and I64 and adding that to my array before dynamic data type conversion but when I lose precision.  I need to have at least millisecond resolution.  I know I lose precision because the timestamp is two 64bit values.  Upper 64bits are whole seconds since epoch and lower 64bits are fractions of a second.  I would even be happy sending those two numbers split into my tdms file and converting at a later date, but can't seem to even do that.  Any help would be appreciated.

[TCPlomp · Accepted solution]

The natural way would be using a waveform.

You could add your timestamp as two U64 (using typecast to U64 array) as properties of the channels as teh t0 of the data.

Ton

[boostinallovryou]

Typecasting to an array of U64's would be great.  I know about the typecast block, I know what the array constant block, but where is there a U64 constant to shove into the array constant??

[boostinallovryou]

Let me scratch my reply.  I just figured out how to get a U64 constant.  Thanks again for the help.