How to configure NI-STC3 to trigger on logical condition of multiple digital inputs?

[johnchih123]

I have an application where I need to AND two digital inputs. When both inputs are high, it triggers an analog input channel to sample the signal. The number of samples and timing must be pre-configured. Can the new NI-STC3 series DAQ board do this?

[rkm44]

Hi johnchih123,

Yes, this can be done using our X series boards. To do this, I would suggest looking into the Start Digital Pattern Trigger When Property http://zone.ni.com/reference/en-XX/help/370469AA-01/daqmxprop/attr1411/

For more information I would look up Digital Pattern Triggering in the LabVIEW help.

The digital paittern is specified using the following characters:

• X: ignore the physical channel
• 0: Match on a logic low level on the physical channel
• 1: Match on a logic high level on the physical channel
• R: Match on rising edge on the physical channel
• E: Match on either rising or falling edge on the physical channel
• F: Match on falling edge on the physical channel 

I hope this was what you were looking for. If not please let us know and we will do our best to help.

Thanks,

[John_P1]

It's a shame the linked document doesn't list the supported devices for this property, but if you try using this you'll find that X Series doesn't support pattern match triggering (it's a feature for the 653x digital devices which also use DAQmx).

There isn't a way to configure the STC-3 to AND two signals together using DAQmx.  Depending on the exact behavior you need it might be possible to cobble something together using multiple counters and/or change detection timing but in all honesty I would just go with an external AND gate regardless.

Best Regards,