Changing the data acquisition speed

[xXChazXx]

I am recording temperature using a cFP-2120 (cFP-TC-120 + capable). Could someone please explain to me how to slow down the data acquisition so that it is every minute rather than every ms. This is for two reasons. Firstly the data file's that are being produced are getting so big that excel cannot fit all the data to a sheet and notepad cannot open them. I did have a .lvm file that was over 700mb overnight. Secondly the data is displayed on a graph when it is being recorded (Left hand graph on the vi), but it is being plotted an varying rates. Sometimes it is every millisecond, others it is every few seconds.

I have attached  my VI, but i cant attach my text file is too lig to be uploaded (that was after 10min data recording)

Thanks

Chaz

[Hillman · Accepted solution]

Hi Chaz,

Thanks for the post and I hope your well.

To alter the rate of datalogging you need to use loop timing. You can do this with a timed loop structure (best) or with a timing vi (such as wait until next multiple) in the loop (good). This knowledgebase article explains it all in more detail, 

How Do I Adjust the Analog Input Rate of My FieldPoint Modules?

http://digital.ni.com/public.nsf/allkb/3DCBB324D23FD637862571320066AA7A?OpenDocument

Hope this helps,

[xXChazXx]

Thanks 🙂

Works a charm... never used the timed loop before.

[Hillman]

Hi Chaz,

Thanks for getting back - they are very handy when programming real-time systems, because you can select clock sources, priories and see clearly the loop rate for the structures.

Incase your interested, a few interesting links 😄

Configuring Timed Loops: help file. BUT think you'd prefer, Creating Deterministic Applications Using the Timed Loop (ETS, VxWorks) (RT Module).

Real-Time Applications with the Timed Loop: video

Glad it helped.