sub sampled data logging

[1113562]

I am sampling an analogue signal at 500Hz using an X series Multifunction DAQ and a DAQ assistant function set to continuous sampling and a buffer set to 2,  I then perform an RMS measurement on the sampled values using Amplitude and Level Measurement function.  I filter this using  a Filter function set to smoothing over a number of samples (moving average).  All of these functions are contained in a While Loop.  This all works fine.  I now want to data log the moving average RMS value to file  but not at the 500 Hz signal sampling rate but at 1 Hz,  If I use the Write to Measurement File function there is no option to reduce the file write rate.  I have tried using the decimate vi function to reduce the data array to a reduced number of samples per second but the Write to Measurement File function still writes at 500 Hz rate although a value only appears at the decimated rate, i.e. the file is still huge with lots of blank date/time stamp entries between values.  I guess I need nested loops but I am not that familiar with this to do what I want.  You would think this would be a common problem that lots of users come across but I cannot find a simple answer in the examples.  Is there a Write to Measurement File type function where you just select the write rate in seconds independant of the data sampling rate?

[JP-NI]

Hi there,

I notice you haven't had a reply on this post yet and it's been open a while.

Is this still an issue for you or have you found an answer?

Cheers

Jimmy