Help with AI Trigger!

[markwysong]

Please help! I'm an experienced LabVIEW user, and this one is really
puzzling me. I have a (2) PXI-6070E MIO boards in a PXI chassis. What
I would like to do is have a data acquisition with an analog trigger.
When the analog trigger occurs, I would like to start a counter output.
Therefore, I'd really like to route the "AI start trigger" to the
counter gate. Here's what has happened:

1) I can set up the analog trigger, and the data acquires when the
signal goes above the trigger level, just like it's supposed to.

2) I can manually start the counter by toggling the gate by hand and
watching the output toggle.

3) I can't get the AI start trigger to be an output to anything--a PFI,
an RTSI line, nothing. How do I route this
signal to gate of the
counter? If I can get that, I know it will work.

Mark


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[tnewton]

A little background:
The signal you are looking for is ATCOUT. This is the digital trigger signal that is generated internally when the specified analog trigger conditions are met. It is not available as an output directly or by routing to a PFI. However...

You CAN get to the signal indirectly. Configure the analog trigger to use ATCOUT (not the stop or start triggers). Configure a counter to use PFI0 as one of its inputs. Route that input (gate or source)to a PFI: the digital signal ATCOUT should be available there.

I wrote an example in LabVIEW 6i that does exactly this for a PCI-E series card. I attached it and put it on our ftp site (I work here @ NI).
ftp://ftp.ni.com/incoming/ATCOUT.vi

[markwysong@my-deja.com]

I got it. Although I am not able to specifically route the AI trigger
to a PFI, I can route it to a RTSI line. (If I'm triggering a counter
from the same MIO board, I don't even need to do that--see below).

What I found is that buried deep in the Generate Delayed Pulse VI, there
is a VI called CTR Mode Config. There is a cluster input to this VI
which contains the parameter for the gate line. If you check the help
on this VI, it shows that you can select AI trigger or RTSI line as the
counter gate, but the cluster control they've put on the front panel
doesn't allow you to select this as an option.

Redoing the control (basically deleting it, putting the wiring tool on
the input, and then selecting create control) allowed me to select the
appropr
iate line, and thus my triggering worked correctly. I don't know
why they don't have all the selections available in the control they
made for this VI. *shrug*

Mark

In article <8ra9nl$nh0$1@nnrp1.deja.com>,
mark.wysong@ae.ge.com wrote:
> Please help! I'm an experienced LabVIEW user, and this one is really
> puzzling me. I have a (2) PXI-6070E MIO boards in a PXI chassis.
What
> I would like to do is have a data acquisition with an analog trigger.
> When the analog trigger occurs, I would like to start a counter
output.
> Therefore, I'd really like to route the "AI start trigger" to the
> counter gate. Here's what has happened:
>
> 1) I can set up the analog trigger, and the data acquires when the
> signal goes above the trigger level, just like it's supposed to.
>
> 2) I can manually start the counter by toggling the gate by hand and
> watching the output toggle.
>
> 3) I can't get the AI start trigger to be an output to anything--a
PFI,
> an RTSI line, nothing. How do I ro
ute this signal to gate of the
> counter? If I can get that, I know it will work.
>
> Mark
>
> Sent via Deja.com http://www.deja.com/
> Before you buy.
>


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Before you buy.