How to record continuous datas on Excel?

[Norbert_B]

Julie,

sadly, the screenshot doesn't reveal how you set up the DAQ assistant.
As you might already know, i am not very happy about using expressVIs, esp. the DAQ assistant. Don't take me wrong, it is a nice tool to create simple DAQ-programs very fast.

Regarding your question:
It seems that you started from the example i suggested which is good. I am just wondering why you removed most of the DAQmx-functions and replaced them with the DAQ assistant. That implies that you don't know how to use the DAQmx API for DAQ-applications.
Here is an example how to include channels with totally different settings in one task. Please note that (despite the settings) they are of the same type (AI here).




So please try again the example from the examplefinder and include the code for the different types of AI (strain and thermocouples).

hope this helps,
Norbert

Message Edited by Norbert B on 09-04-2007 02:37 AM

[1jsepanski]

Hi,

I was using Signal Express because it seems easier, and I didn't know how to put 2 inputs with the other way.

I made a program with what you told me but I have an error, and I don't understand what it means. I want to record at a rate of 1000Hz and 10 samples.

I don't understand the use of the box Waveform, that's why I deleted it, and for the Sample Clock I deleted it because I thought it was included in the DAQ Assistant.

We Signal Express I can calibrate my strain gauge, can I do that with the other way?

Here is the new program and the error.

Thank you very much.

[Norbert_B]

Julie,

the reason for the error is that you are mixing up finite acquisition with continuous acquisition. In the DAQassistant, its just a mouseclick. Since you are getting to a level where you are going to programm it instead of simply configuring it, you have to do one thing more: create a constant 🙂

Here is a screenshot where you have to change the setting from finite to continuous:



Since the screenshot is not too good regarding where the constant has to be placed here another one:



hope this helps,
Norbert

Message Edited by Norbert B on 09-05-2007 02:45 AM

[1jsepanski]

Hi Norbert,

I managed to do what you told me and I have a problem to save. When I save, the settings are not saved.

I can make continuous records now, but now I need to make long time measurements, so I should find a way to make a mean of X measurements and save the average in an array for example.  And make an other average Y seconds later and record the average and so on.

I managed to make something but I don't know how to link my analog signal in an array.

In the code I join you there is the previous program and below the code I made to make an average.

Thank you very much.

Julie

[Norbert_B]

Julie,

first of all since it seems that your application should be finished by pressing the "stop"-button, you always want to have continuous acquisition. Therefore you better use a constant instead of a control for the sample mode.

Regarding your mean and average function: the data-array is part of the waveform-datatype the DAQmx read returns. Since you dont need/want the time-info of the waveform, you better configure the DAQmx Read to "Analog 2D DBL NChan NSamp". You then have to split up the 2D-array to as many 1D-arrays as your number of channels. Then you can do your mathematics on each of those 1D-arrays.

hope this helps,
Norbert