Data collection problem from multiple channels

[LiaZ]

Hello,

I just started using SignalExpress (Ver.2.5.1 Tektronix) last week, and I have a question on signal acquisition.

In my project I just have 2 steps, 1st is data acquisition from the oscilloscope from 3 channels, and 2nd is to save the data to a txt file.

I used Ch1 as the trigger signal, and want to collect data of all 3 channels every time I send a pulse signal to Ch1. But the problem is that
it seems I need to trigger 3 times to get the waveform displayed on SignalExpress, and have one txt file saved. If I have 2 channels, I need to
trigger twice.

Has anyone ever had this problem? Is there any setting I need to change on the scope or the SignalExpress to collect data multiple channels simultaneously?

Thanks in advance!

Best,

Lia

[DFGray]

That is odd.  Please post your project so we can take a look.  You should be able to trigger, take data, and save all three channels in a single iteration of your project.

[LiaZ]

Attached is my project. It's very simple, just 2 steps: collecting data from 3 channels from TDS 2014C, using Ch1 as the trigger signal, and then save the data to a txt file.

Please let me know if there is anything wrong with the project.

Thanks!

[NateBraska]

Hi Lia,

I am unable to open your project, but to triggering off of one signal should not be too tough. You need to include the device channels you want to record (from the "Channel View" menu at the bottom of the page), then check the channels you would like to record in the "Recording Options" tab (from picture "Recording Data"), and finally right-click on the acquire task ( Insert After > Execution Control > Trigger). From there it will trigger from all three channels; to change it to one channel, click on the drop down arrow (Next to Voltage in my example picture "SigExpTrigger") to pick the specific channel.

Be sure to also to change the trigger "Level" under the "Step Setup" tab.

Let me know how else I can help with this.

Regards,

Nathan B

Applications Engineer

National Instruments

[LiaZ]

Thank you, Nathan.

I'd like to collect data from all 4 channels with one trigger. The problem is that I need to trigger 4 times to get update waveform in the data view window. If I only trigger once, the program will just be waiting for 3 more triggers to update the waveform and save the data to a .txt file. I contacted NI and also Tektronix, and it seems that I cannot collect 4 channels of data with a single trigger (which is not very reasonable to me...). I've written our own LabView VI to do the work, and the VI is working okay, and is faster than SignalExpress. So I think we'll use the VI instead of SignalExpress for future data collection.

Again, thank you for your reply!