How to lower sampling rate below 1Hz using 6036E-DAQ Card

[pdelmar]

Hi,

I'm using the 6036E DAQ Card (PCMCIA) with Labview Express 7.  I have written a program to save temperatures from thermocouples to a text file.  Using the DAQ Assistant I have only been able to function (no errors) at a minimum sampling rate of 1Hz.  However, I will be running this program for 1000's of hours.  Is there some way to lower the sampling rate to say .01Hz?

[Dennis_Knutson]

You can sample once a second, once a minute, once an hour, once a day, etc. In the assistnat, just set the acquisition mode to On Demand and have the assistant inside a while loop. Now, use the functions on the timing palette to control when you take a sample. For example, you can have an Elaspsed Time function and the assistant inside a case statement.

[ryan_d]

Hi pdelmar,

Dennis is correct. The pictures below demonstrate how to make the changes in the DAQ Assistant and on the block diagram. In the block diagram, notice that the timing is set in milliseconds and that a new data point will be acquired approximately once every 100 seconds.

If you have any questions please post back. Have a great day!

Message Edited by ryan_d on 11-05-2007 10:55 AM

[pdelmar]

Thanks a lot guys!

-Paul

[pdelmar]

Using an almost identical block diagram to the one provided above, I am still have trouble configuring the waveform graph.  Is there a way to have the graph follow the signal with time (updating the x values)?

[Dennis_Knutson]

You should probably be using a chart instead of a graph. With a graph, unless you use a shift register to keep old values, you'll get a new display each time. A chart has a history. To have the x axis display time, look at the shipping example called Real-Time Chart (Help>Find Examples - Search tab, keyword charts).