triggered output with delay

[Emile de Kleine]

Hi,

I want to generate an output (a sound wave) a specific time after an
external trigger occurs. What would be a straightforward solution?

I can let the software wait for some time, but I rather have the
hardware doing the timing. I also took a look at pulse generation by
counters, but these can't be triggered by an external trigger as it
seems.

Any suggestions? Cheers,
Emile

[LA 75]

Hello Emile,

That can certainly be done. I need you to answer me some questions though before we start working on this:

1. Is your output waveform going to be analag?
2. What software (including version) and DAQ board do you have?

There are a number of shipping examples that we can use as reference if you are using LabVIEW or CVI. Please let me know about this and I will tell you which one would work better for you.

Thanks,

LA

[Emile de Kleine]

In article <506500000005000000FED80100-1079395200000@exchange.ni.com>,
LA wrote:

> Hello Emile,
>
> That can certainly be done. I need you to answer me some questions
> though before we start working on this:
>
> 1. Is your output waveform going to be analag?

Yes.

> 2. What software (including version) and DAQ board do you have?

Labview6i, v.6.0 with a BNC-2110.

> There are a number of shipping examples that we can use as reference
> if you are using LabVIEW or CVI. Please let me know about this and I
> will tell you which one would work better for you.

Would be nice. Best wishes,
Emile

[LA 75]

Hello Emile,

You didn't specify me what DAQ board you are using (PCI, PXI,etc), but anyways, if you have an E-series board, you can use one of the shipping examples called Cont Gen ExtCLk E-series D-trig.vi (Found in Help=>Find Examples=>Hardware Input and output=>Analog Output)

please let me know if it was useful or if you have any additional questions

LA

[Emile de Kleine]

Hi LA,

I use a PXI with a BNC-2110 connected to it.

I already created something like the example you mentioned. The only
thing is that I want to the output to start a specified time after the
trigger occurs.

Emile

In article <5065000000050000004DDA0100-1079395200000@exchange.ni.com>,
LA wrote:
> Hello Emile,
>
> You didn't specify me what DAQ board you are using (PCI, PXI,etc), but
> anyways, if you have an E-series board, you can use one of the
> shipping examples called Cont Gen ExtCLk E-series D-trig.vi (Found in
> Help=>Find Examples=>Hardware Input and output=>Analog Output)
>
> please let me know if it was useful or if you have any additional
> questions
>
> LA

[LA 75]

Hi Emile,

I know this can be done easily with DAQmx (there is a function called DAQmx Trigger Property Node, where you can specify a time after your trigger occur.) Since you are using LabVIEW 6.1 (and therefore Traditional DAQ), things can be a little bit harder, but try looking for a function called 'scan clock gating.' This function can be used to pause your triggering.

Let me know if you have any additional questions.

LA

[Emile de Kleine]

In article <50650000000500000015DB0100-1079395200000@exchange.ni.com>,
LA wrote:

> Hi Emile,
>
> I know this can be done easily with DAQmx (there is a function called
> DAQmx Trigger Property Node, where you can specify a time after your
> trigger occur.) Since you are using LabVIEW 6.1 (and therefore
> Traditional DAQ), things can be a little bit harder, but try looking
> for a function called 'scan clock gating.' This function can be used
> to pause your triggering.
>
> Let me know if you have any additional questions.
>

I am not sure I know what you mean. I don't want the triggering to be
gated, but the AO has to start a certain time (a few seconds) after the
external trigger occurs.

Emile

[LA 75]

Emile,

I browsed through all the AO advanced palette functions and saw a function called AO control where you can specify pause triggering. You could start off your generation with a pause, and then change it to start after a certain time.

Another option you have is to generate a dc line with a value of 0 at the beginning. By knowing the number of points generated per second and specifying the number of points you want to write with a value of 0,you can then regulate the time of values of 0 you want to generate before starting your actual waveform generation.

Let me know if this helps.

LA