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Need help on "trigger output"

Posted: Tue Apr 06, 2010 6:34 am
by dao
We have two computers, A and B. Now computer A is used for signal acquisition, and computer B is used for sending start triggers.
In computer A, after acquisition and analysis, we need send some signals back to computer B, is it possible to send the signals(A->B) through trigger output?

In FAQ, it mentioned "The trigger output signals can be controlled with an extra independent LabVIEW thread integrated in the BioSemi acquisition software"

However, I did not find out the way to write out the trigger output signals. Anyone give me some clues? Thanks a lot.

Posted: Wed Apr 07, 2010 2:07 pm
by Coen
Refer to ActiView Light (http://www.biosemi.com/download/ActiView604-Light.zip) for an example of the extra LabVIEW code needed to sent output triggers form ActiView to the trigger port on the USB receiver.

Best regards, Coen

Posted: Fri May 07, 2010 6:14 am
by dao
Hi Coen,

Thanks a lot.

After I read the ActiView Light version, I guess the function with name "usb_write" should be used for sending output triggers to USB receiver, is it correct?

And if "usb_write" can be used for sending output triggers, I still have no idea how should I make use of this function.

I noticed the input parameter of "usb_write" included a vector with 64 bytes, and have no idea how should I write exact data(eg. 255) to trigger out pins via this vector.

Could you kindly give me more suggestions? Thanks again.

[quote="Coen"]Refer to ActiView Light (http://www.biosemi.com/download/ActiView604-Light.zip) for an example of the extra LabVIEW code needed to sent output triggers form ActiView to the trigger port on the USB receiver.

Best regards, Coen[/quote]

Posted: Fri May 07, 2010 11:37 am
by Coen
The USB_WRITE function call is indeed controlled by a 1-dim array of 64 bytes. The first byte controls acquisition start-stop. The second and third bytes controls the 15 output triggers (output 16 is fixed on the sample clock). The rest of the bytes are not used.

Best regards, Coen (BioSemi)