Synchronizing tasks using LabVIEW and NI USB 6001

[Gio315]

Hello, 

I am using an NI USB 6001 to synchronize my output and acquisition but I am not sure this DAQ model can help me with what I need to do.

1. I need to generate a slow not periodic ramp (10-100s)

2. I need to send a trigger signal to the wave-function generator for initiating the application of the signal to my circuit. I need this trigger to be synchronized with the analog output (the ramp at point 1.) in such a way that it starts after a given time the ramp has reached the final value.

I have generated the ramp as an analog output of the NI USB 6001 but I am having troubles generating the trigger signal synchronized with the analog output. All the solutions I try they give me some kind of error and I am starting wondering if I can do it at all with NI USB 6001 or I need another model.

The errors I get are: 

Error-200375 when I use DaQmx Export Signal to export the start trigger and when I use DAQmx Create channel (Co-Pulse Generator ticks) to generate a pulse it does not allow me to select the output terminal to which send the pulse.

Thanks in advance for the help!

[Bob_Schor]

OK, we know what you want to do, we know something about the hardware, we know a few of the functions you used, we know you got an error, the only thing we don't know is what you told LabVIEW to do for you.  I'm going to guess that your have a problem in your code.  However, without seeing your code (and this means that you attach all of the VIs, not pictures, so we can understand what you told LabVIEW to do, and maybe explain why it "did what you told it to do, rather than doing what you want it to do".

Please attach your LabVIEW code -- it is the only way for us to know what you told your system to do, and where mistakes may have been made.

Bob Schor

[Nathan-M]

The USB-6001 uses PFI lines as inputs only, and the counter in the device can only be used to count edges - not to generate signals. It is a low cost device and so the functionality is limited compared to other DAQ devices. Your suspicion about it being the wrong device is probably true. 

From page 10 of the user manual (http://www.ni.com/pdf/manuals/374259a.pdf)

It sounds like you want this trigger to occur after an arbitrary amount of time, dependent on the length of the ramp signal. You may be able to use the other Analog Output channel as your trigger by writing a 5 V square pulse to the output for a few samples and then 0 V afterwards.