Trigger and Gate Only Returns One Channel

[kkrizka]

Hello all,

I am trying to write a VI that will run in the background and start writing some data to a file when it detects a signal. For detecting the signal, the VI uses the "Trigger and Gate" express VI to see when the input voltage goes above a treshhold. Then I plan to write whatever data comes out of the "Triggered Signal" output.

There are 8 channels, with the 6th one being the channel that is being checked for a signal. I have configured the "Trigger and Gate" express VI to trigger when that channel reaches 0.01 V and it does trigger when that happens. However the problem is that the "Triggered Signal" output only contains data for the first channel, and I want it to contain all of the channels.

I don't have access to the device that will be sending the data right now, so I am testing the VI using the "Read From Measurements File" express VI. It reads from a file that contains data that I saved from the device previously. When I set the the "Retrieve segments of specified size" for the express VI, so I can see how it progresses, I get the error I mentioned above. When I set it to "Retrieve segments of original size" (the file contains only 1 segment, so it reads all data), everything works as expected.

Any ideas as to what I am doing wrong?

I attached the VI with some sample data.

[Joe D.]

Hi krizka,

There are two really good examples that can be found using the NI Example Finder (help -> find examples). These are under Hardware Input and Output -> Analog Measurements -> Voltage  

Cont Acq&Graph Voltage-Int Clk-Analog Start.vi

Cont Acq&Graph Voltage-Write Data to File (TDMS).vi 

These will give you a good start point. Please feel free to ask if you have any questions

[AndrewMc]

As of DAQmx 9.0, the TDMS examples should be using are called "TDMS Streaming - ..." and can be found under Hardware I/O>>DAQmx>>Analog Input>>Voltage.