How to use DAQ?

[Gaudier]

Im looking for information about how to choose the right NI-DAQ devise to measure current and voltage from a probe using LabVIEW.

[Ayman K]

Hello Zurdo,

National Instruments offers variety of data acquisition devices that you could use to measure voltage and current, however each has its own specs. I would really appreciate it if your could post your requirments so that I could guide you to the right card that you would need to use. At the same time, please visit the Data Acquisition Wizard and select all your specs to see a list of the DAQ cards that are suitable for your applications.

Thank you again for your time.

Regards,

Ayman K
Applications Engineer
National Instruments

[Gaudier]

Hello Ayman K , thanks for your attention. I yust started a new job in a Plasma Laboratory and my bos ask me to measure plasma parameters using a Langmuir Probe and send the information trougth a sweeper to LabVIEW and show a current vs voltage graph. Using the probe is easy, the thing is that I have never used LabVIEW before and I dont know exactlly what I need. I think I need a DAQ with one I input and one V output.
Thanks,
Zurdo de Cupey.

[Tom_W_[DE]]

Hi Zurdo-

Hopefully you have had the opportunity to view the Data Acquisition Wizard that Ayman suggested.

In order to measure current, you will also need one of the signal conditioning options described in KnowledgeBase How Can I Do Current Measurements with NI Products?. Alternatively, you can measure current with relatively good accuracy using the method described in KnowledgeBase Measuring Current Using the Analog Input of a DAQ Board?

Once you have selected the DAQ board that meets your requirements for sampling rate and resolution, programming in LabVIEW is extremely fast and easy. You can find many excellent NI-DAQmx examples for LabVIEW after installing the NI-DAQ driver by accessing the NI Example Finder at Help>Find Examples.

Please let us know if you have any additional questions.

Thanks,

[Gaudier]

Hi, I yust found here NI-488.2 for Windows , and a cable to conect a 2400 series sourcemeter to the computer. Would that work? How do I find the hardware from LabVIEW.
thanks ,Zurdo .

[Tom_W_[DE]]

Hi Zurdo-

A quick search of the Instrument Driver Network at ni.com shows that LabVIEW drivers for the Keithley device are only available from Keithley. I would check with them if you prefer to use this device.

Thanks,

[Gaudier]

Hi, thanks for your help. This is what I found in the lab.: the Keithley 2400, its driver, NI 763507-02 rev 1 type-x2 (cable) , NI 488.2 for windows(software),PCI-GPIB (hardware),I conected all this ,opend LabVIEW (wich nobody in this lab. has used before)and started learning using the getting started .But when I got to the part I really need to learn (Lesson 4: Acquiring Data and Communicating with Instruments)the program did not found the input devise.
Beside my poor Knowedge in this procedure, what is my problem?
Zurdo

[Tom_W_[DE]]

Hi Zurdo-

I assume you're trying to access the Keithley device via GPIB. In order to do this, I would first make sure the device is recognized in Measurement and Automation Explorer (MAX). This can be found under Start>Programs>National Instruments>Measurement and Automation.

After opening MAX, expand the Devices and Interfaces and left-click on your GPIB interface. Click Scan for Instruments and make sure your instrument is properly enumerated. You should then be able to access it in LabVIEW.

You might be able to find better advice for working with this instrument on the Instrument Control section of this forum as working with this GPIB device is unrelated to DAQ.