problem about DAQ voltage and temperature sampling

[hanwei]

Hi group:

I  want to implement voltage and temperature data sampling by using DAQ card PCI-6040E , SCXI 1001 chasis, SCXI-1102, and  1300.

But now I meet a problem. When I want to collect the voltage data and temperature data in one same loop, it is not working.

Can anybody knows what 's problem about it and how to fix it.

Thanks a lot , I really appreciate your help, if you can help me

The example codes is attached here

Best regards

Wei

[LabBEAN]

Wei,

You cannot run two tasks simultaneously with E-Series DAQ cards.  See here:

http://digital.ni.com/public.nsf/allkb/BF4038CAA7CBCDBF86256C360062A192

However, you should be able to open MAX (Measurement & Automation Explorer) and create a New Task by expanding "Data Neighborhood", right clicking "NI-DAQmx Tasks", selecting "Create...", Acquire Signals, Analog Input, then Voltage... Once your task is configured, it should appear under NI-DAQmx Tasks on the left.  You can then select it and add a "Thermocouple" channel by clicking the blue "+" on the Configuration tab in the center of the screen.  In your LabVIEW code, create a control off of the "task/channels in" input to your DAQmx Start Task VI.  On your front panel, the task you created should appear in this new control.  Adjust your LabVIEW code accordingly to key off the task instead of the physical channels.  If parameters about the individual channels change, you can access those in MAX.

Take care,

Jason

CLD

Blue Ridge Test, Inc.

www.blueridgetest.com

[Amanda_H]

Thanks for the great response, Jason! Was this able to clear up your problem, Wei?

[hanwei]

Thanks for yor response,  After I just creat one task and connect the"DAQmx creat virtual channel.vi" for  temperature and voltage in series. it is working.

I really appreciate your help

best regards

[LabBEAN]

Wei,

Happy to help.  After the setup phase of your experiment (i.e. configuring hardware & signal conditioning, verifying connectivity in MAX, demonstrating various portions in LabVIEW, etc.), you might consider your architecture before moving forward.  How will you store your data?  How will you view / analyze the data later?  Is the architecture readable, scalable, and maintainable?  What will happen when you want new features (e.g printing reports, controlling external equipment or processes while saving data and displaying results, standard logging intervals, or user logins)?  What kind of user interface will you use?

Set yourself up for success long term by thinking about the right architecture today.  We frequently have customers whose "simple engineering experiment" grew on them.  And, interpetting bad LabVIEW code a year into a project can be a lot like deciphering abstract art.  Any of us (NI Alliance Partners) would be happy to discuss your application with you before it gets to that point.

Take care,
Jason

Certified LabVIEW Developer

www.blueridgetest.com