Triggers and acquiring data question

[Vr6Fidelity]

Im running LV 7.1 with a 6062E DAQ card, and the SCB-68 Terminal block, my signals are differential

Im aquring signals from a pulsatile system, my transducers are very fast.

I need to trigger my data aquisition off one of the signals. How do i do that? The frequency of sampling is not terribly fast but it is not a constant rate (1.25hz) I WAS sampling at 1.25hz or multiples of it but alas my acuisition falls in and out of phase with the physical system.

Here is the VI that runs at a constant Rate:

And my feeble attempt at triggering:

[EdDickens]

The first thing I would do is switch from using the Traditional DAQ to the DAQmx driver. Eventually I think the Traditional DAQ will no longer be supported, so you might as well make the switch and get used to the new driver. It's a much better driver and has many advantages anyway, and I think it's a lot easier to use.

The good news is the your 6062E card supports both Analog and Digital triggering. This gives you some good options to set things up.

Start off by looking in the shipping examples (Help menu>Find Examples) and search for Trigger and look through the listed examples to see if something is close to what you are trying to do. You can then either adapt that into your VI or just modify the example and save it with a different name.

Let us know if you still need some help.

Ed

[NIquist]

Before you go any further with traditional DAQ VIs I suggest you take a peek at some of DAQmx Synchronization examples.  DAQmx makes this type of thing MUCH simpler once you become familiar with its paradigms.  If you don't have a good reason for sticking with the old DAQ, switch over now.  You'll find that your app will be so easy to code it's almost embarassing. 

[Vr6Fidelity]

Ok, ok i know MX is better but i dont know how to use it at all.

But since im on a tight time table can sombody help me fuble thru this in Traditional?

Im getting my wisdom teeth out soon and will have plenty of time to play with MX, also i do have hardware that is NOT mx supported.

Anybody look at my VI's? Could you? Thanks.

[EdDickens]

I don't have Traditional DAQ installed, so I can't really do much with your examples.

I would still suggest looking through the shipping examples for something that sounds close to what you are trying to do. Trad. DAQ does install examples and should have something that's pretty close.

Ed

[NIquist]

Your triggering is not working because the AI Acquire Waveforms.VI you use in the loop is upper level and has it's own triggering setup in it's subVIs.  That is why it has an input for 'device' rather than for a taskID.  In your second program you did not wire the config VIs taskID output to anything so it will not work as you expected.

Here is a quick & dirty way to get you going:

Start with your first program and open AI Acquire Waveforms. 

On it's diagram you will find AI waveform scan BUT, the trigger and clock input has no control.

Create a control for the trigger and clock and add it to the connector pane (there is any empty box for you to use).

Now AI Aquire Waveforms will have a connector for trigger and clock in your top level VI.

Create a control there and set your trigger type, edge, etc.

A better method is to look at what is inside the AI Waveform Scan.vi and code something similar but without all the un-needed overhead.  Also look at examples like 'Aquire 1 Point Digital Trig.vi' to get the gist of using the lower level DAQ VIs.

Hope this helps,

K