How to record continuous datas on Excel?

[1jsepanski]

Hi,

I'm beginner in Labview.

I want to see and record the datas of a strain gage and a thermocouple at the same time.

It is working but it just records the beginning of the measure because there are too many points.

I tried to lower the rate and number of samples but when it's too low it doesn't work.

How can I reduce the speed and the number of samples? in order to collect all my datas?  or maybe can I use something to make an average?

Thank you in advance for your answer.

Julie

[Norbert_B]

Julie,

please post your code you are currently working with.

Norbert B.

[1jsepanski]

Here is the program I'm working with.

I use a NI cRIO-9211 for the temperature and a NI 9237 for the strain.

Thank you

Julie

[Norbert_B]

Julie,

you have at least two possibilities to solve your issue:
a) Change "Write To Measurement File" to either append to the file or to create a sequence of files.
b) Remove all ExpressVIs and implement the application by DAQmx- and FileIOfunctions. You can find an example for this in the examplefinder in Daqmx->AnalogIn->Voltage-> "Cont Acq&Graph Voltage - Write Data to File (TDMS).vi".

Ok, TDMS is a fileformat you maybe dont want to use, but you can simply replace those vis by appropriate "standard"-fileIO-functions.

hope this helps,
Norbert

[Herbert Engels]

TDMS is NI's recommended file format for measured data, so it might be exactly the file format you want to use. You can read it into Excel using an Excel Add-In that you can download from ni.com for free. When it comes to the amount of data you store, TDMS can take whatever your hard drive can take, but Excel has some limitations there. To the best of my knowledge, Excel 2007 can take 2 million values per column, whereas older versions take about 65000 values per column.

http://zone.ni.com/devzone/cda/epd/p/id/2944

Hope that helps,
Herbert

[1jsepanski]

Hi, thank you very much.

 I made a new program with the TDMS file but I have another problem, I don't see the X axis which is the time.

Do you know how I can have it?

Thank you

Julie

[Herbert Engels]

I take it that you use waveforms in your LabVIEW code. In that case, T0 and dT will be stored as channel properties (wf_start_time and wf_increment). You can either calculate your x values from that in Excel, or you can do that in LabVIEW and store them to the file as a timestamp channel (if you need a full date/time stamp) or double channel (if you just count seconds or so, starting at 0).

Herbert

[1jsepanski]

Hi, the program is working and I can take the data I want in Excel, so it's good. Thank you very much.

For the time, I will calculate it.

There is still a problem in my program, because when I want to acquire less samples and at a lower rate, it doesn't work, an error appears.

How can I acquire less values.?

Thank you very much.

Julie Sepanski 

[Norbert_B]

Julie,

please post your current code or at least an exerpt which shows the data-acquisition and login...

Norbert

Message Edited by Norbert B on 09-04-2007 02:01 AM

[1jsepanski]

Hi,

I just send you a copy of my code because I can't have the program on the computer I am.

I modify the rate and teh number of samples by clicking on the DAQ assistant.

Julie