Simultaneously Record Multiple DAQ Channels

[ssward]

I am currently set up to read two channels in from the DAQ using DAQ Assistant. I am wondering what the best way would be to go about sampling these channels at the same time, or as close as possible. Attached is the vi I am currently using.

Thanks,

Sawyer

[achapAriff]

I having the same problem. I need to make a program that can log data from 4 sensor at the same time. Running individually have no problem but when i try to run all at the same time there is an error.

[crossrulz]

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@ssward wrote:

I am currently set up to read two channels in from the DAQ using DAQ Assistant. I am wondering what the best way would be to go about sampling these channels at the same time, or as close as possible. Attached is the vi I am currently using.

Thanks,

Sawyer

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They are sampling at the same time (or extremely close to each other).  I'm not sure what your actual problem is.

[crossrulz]

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@achapAriff wrote:

I having the same problem. I need to make a program that can log data from 4 sensor at the same time. Running individually have no problem but when i try to run all at the same time there is an error.

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Any particular format you want to save your data in?  I recommend TDMS since there is a very handy Configure Logging function in DAQmx to save your data to disk (TDMS file) as you read it.

[ssward]

I was just wondering if there was a way to get them closer, or if this way is good enough.

--Sawyer

[crossrulz]

Reading the two channels in a single task is going to make them as close as possible in sampling time.

[NIquist · Accepted solution]

DAQmx handles all the timing under the hood and does pretty well.  If you want to tweak the advanced timing settings you can but of course you'll have to give up the DAQ ASSistant and write real LabVIEW code.  

I'm assuming you're using a multiplexing card right?  The only actual solution for true simultaneous sampling is to buy a card that has multiple ADCs like the S-Series cards.

To the second poster:  You don't have the same problem as the OP.  He can set up multiple channels.  If you want help, you need to provide more information than "it gives an error".

EDIT: I'll bet you're trying to use separate tasks for every input aren't you.  You'll get a resource conflict error if you do.  You have to use ONE task and set up multiple channels in that task to collect more than one signal.

[ssward]

Thanks for the information.