How do I initiate a 5-second delay from starting the program to data aquisition?

[bgaertner]

Hi group,

Please pardon my utter ignorance.  I'm using LabView 8.6 on Mac OS/X Tiger with the DAQ-6009 USB.  I got the block diagram from this board: it's called DAQmx Base AI-AO_LV86.vi.  The only modification I've made is to add a "write to Measurement file"...

My basic project is I'm sending voltage out and recording temperature in.  In the mean time, I'm also recording a live animal as the temperature changes-- the video is controlled using a separate program.

I need to be able to sync the time the video starts recording with the time the program starts.  The easiest way for me to do this is to hit "play" on the front panel, then hit "import" on the video as the program begins.

So,  how do I put a delay in?

[johnsold]

You can do this several ways.  One is to use the Wait (ms) functions.  Another is the Time Delay Express VI.

When I have done projects using video recorders, we start the video recorder, wait several seconds, then start the experimental trial by sending a synchronizing pulse which shows up on both the video and in the analog in data stream.  Use one of the digital outputs to drive an LED.  The camera record the light turning on and the voltage across the LED is recorded on an additional AI channel.  Having synchronized data once saved a graduate student from having to repeat 6 months of work.

We also were able to control the video recorder from the LV program. We modified a remote control to allow a digital output from the computer to "push" one of the buttons on the remote control.

Lynn 

[bgaertner]

Hey Lynn,

I think I need further instruction.  I know nothing about labview... can you walk me through the steps to add this Wait function?  I can send you a screenshot of my VI when I get to my computer... that seems pretty necessary...

[RavensFan]

If you know nothing about LabVIEW, then I recommend you take the tutorials

Here is what Lynn is suggesting.

Message Edited by Ravens Fan on 09-30-2009 09:41 PM