How to make 9229 trigger by data scan

[alex.]

Since 9229(USB casing) not have outside analog trigger, and the signal duration is 12 seconds.

I need to scan the collect data all long, until the threshhold trigger voltage is detected, then start collect 12 Seconds signal.

But after the threshhold is detected, some data may already lost when the 12 second duration collection start.

Also 'how fact to make a scan', The scan to read th data should be in a loop. If set the duration for each loop too big, then may lost data, but if too samll, then may make the Windows hang.

Any suggestion how to read the data scan from the device. Thanks.

[KateB · Accepted solution]

Hi Turbot,



You can simply continuously sampling, and keep data in array.

If data size is larger than 12 second just trim it out, and if threshold is reached, use array subset data to select just 12 second portion.

You may refer to my attached example for more information.



Regards, Kate

[alex.]

Thanks, I am trying to collect 4 channels at same time but got error 50103, seems cannot do at same time, any suggestion?

[KateB]

Hi Turbot,

Just like what other guys told you on another forum that you post.

Just use only one task, and set channel to Dev1/ai0:3.

You also need to change DAQmx read to read from multiple channels.

Regards, Kate