Two AI and AO + saving data

[AlexeyT]

Hello!

I am working on a student final project: Hot Probe measurement. I have a DAQ 6024E card.

I need to measure voltage and temperature (K thermocouple) and then be able to save data in excel or at least text format. Also I want to display temp. while measuring on 7-seg displays: I have four 1-digit displays.

I am thinking about controlling them by two AO of the card - gives me 4 options overall.

I need to measure a TC sample and display it on 7-seg, but since there is only 1 digital port - I can set only 1 digit at the time. So by combination of 2 AO I set proper digit and now need proper number from temp sample - 1 of 4 digit number I get from TC.

I hope it’s not all too complicated.

Resources:

DAQ 6024E

Labview 8.2.1

4 one digit displays

K-type TC

Any help appreciated !

[Ed W]

Hi AlexeyT,

Thank you for posting to the NI forums.  Did you have a specific question about how to program this application or were you just looking for general recommendations?  If you’re just getting started with NI’s products, I would recommend using the LabVIEW Example Finder to begin the programming of the data acquisition.  There are several temperature acquisition examples as well as analog generation examples.  In addition to these, there are also prebuilt AI/AO synchronization examples.  These can all be found by clicking the Help menu and selecting Find Examples.  Browse to Hardware Input and Output >> DAQmx. 

As far as the file I/O is concerned, you can use the Write to Text File Vis to create a csv file and then view this within Excel.  Make sure to open the file before your data acquisition loop and close the file after the loop. 

I hope this helps – please post back if you have any further questions.

Ed W.

Applications Engineer
National Instruments

[AlexeyT]

1 . I have trouble setting two AO to the following sequence: 00 05 50 55 Volts. Depends on that I want to write specific data to the DO port - the data I read form AI. I am think its a simple VI - but still not that simple for me.
2. Can I log data from AI in single sample mode to the file for futher processing ?

Thank You.

[Ed W]

Hi AlexeyT,

There is a nice example that demonstrates software updated analog outputs.  It can be found in the Example Finder under Hardware Input and Output >> DAQmx >> Analog Generation >> Voltage >> Gen Mult Volt Updates-SW Timed.vi.  Besides this, was there something specific about the programming that you didn’t understand, or are you receiving an error message, etc.?  Please post back with more detailed information about the nature of your programming issue.

As far as the data logging is concerned, single sample AI can be written to a file by using the Write to Text File VI each time a sample is acquired.

Best regards,

Ed W.

Applications Engineer

National Instruments