Triggering data acq task from another task

[task]

Hi,
I am using a PCI-6220 (MSeries) and Labview 7.0 and am trying to do the following:

-- output a waveform to my analog output. The waveform is formed (increasing frequencies) and sent to my DAQmx task using the DAQmx timing, DAQmx Write, and DAQmx start task (SEE ATTACHED JPG)
-- input the signal I'm sending out (coming into a AI channel) and another channel. The task is set up to read a finite number of samples at 10000 samples per second.

The problem I have is I would like my acquistion task to start when the output task (freq of 1Hz) crosses 0.0, rising slope. I've tried using the DAQmx Trigger but it will only accept digital inputs.

Any help would be appreciated.

Thanks,
Teri

[George M.]

Hi,

There is a great discussion of using analog triggering in the M Series User Manual:

http://digital.ni.com/manuals.nsf/websearch/9477D6DF1FE5A72986256FAB00633DE4?opendocument

Just search for analog triggering. Once you understand how it is supposed to work, you can then use the LabVIEW example finder under the help menu (Help>>Find Examples). In there you can search for triggering, and then find the example:

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

You can change the default PFI pin to an analog input channel. The trigger line will have to be the first channel used, and then the other channels can be for the acquistion.

I hope this helps, and have a Great Time Programming!

George