DAQmx Event Question

[D60]

Hi, 

There is a DAQmx - EveryNSamplesAcqIntoBuffer event. I have a question about it. I have a task that operates on mutiple channel. For example 5

The help says: 

• Every N Samples Acquired Into Buffer — Occurs when the user-defined number of samples is written from the device to the PC buffer. This works only with devices that support buffered tasks.  

So, If I use this sw event with my task (with 5 challels), what should be the sample interval? - if I want to collect data periodically as follows: I need an event fired when every chanel has acquired 100 samples, - continuously

If I wire 100 for sample interval, this event is fired when 100 sample transfered from device to PC buffer - but I am affraid this is diffierent whan I really need.

Could anyone help me to understand DAQmx event - Channels - and Task ( with multiple channels ) connection?

Or suggest me a solution for my problem?

Thanks in advance.

[Zody]

Hello,

Well, depending on your goal you can do it in two ways.

One is to use this Register DAQmx Events.

 

You can find more information on this forum: http://forums.ni.com/t5/Digital-I-O/PCI-6534-every-N-samples-acquisition-into-buffer-time/td-p/11588...

The other way is to monitor software and send the software trigger. There is a VI for software triggering.

Kind regards,

Ion R.

[Mcdan · Accepted solution]

Durnek,

In DAQmx, a sample refers to data on all channels for a given sample clock.  If you have 5 channels in your task, then each sample includes data from all 5 channels.  In this case, setting the sample interval to 100 will give you 100 reading from all 5 of your channels.

Hope that helps,

Dan

[D60]

Thank you very much!