How to check or reccord data using multi channel(16) DAQ(6220 or 6023E)

[alex.]

There are quite a lot channels.

Does I need to check the channels one by one to see if any signals coming in.

Or there is another correct way to do it.

Thanks.

[Dennis_Knutson]

Explain a bit further. Each time you do a DAQmx Read, there are signals coming in. Do you need to detect if there is a specific signal being read?

[KateB]

If it's possible to have data from all channel, and you really have no idea which one will come in, yes, you've to check it one by one.

[alex.]

Is there a sample for checking one by one, thanks.

[KateB]

If you don't tell anyone the difference between no signal, and signal existed, how can anyone answer your question?

Please try to put more effort on your work.

[alex.]

When there is no signal, the input is just a 0 level voltage.

When signal come, it will be a 50Hz sine wave with several second duration.

I am not sure if the card can do simultaneous data collection. Just wonder any standard mechanism or function block for polling multi-channel with good performance.

Thanks. 

[KateB]

refer to attached file