Help with Acquire N- Multi-Analog Software Trig.vi Example

[PistolPete]

We have an instrument that is outputting a trigger signal which is a +0.3 V
square wave sitting on top of a +1.0 V bias. This signal will not work as a
digital trigger so we routed this line to Ach0. The signal off the
instrument is collected at Ach1. We can see the trigger signal in this
example VI and it triggers correctly at a positive slope and level of 1.3 V.
However, we can not see the signal from channel 1 on any of the displays
regardless how we configure the indicators.

1. Does this VI work for mulitple channels without modification?

2. What should we try next to get both signals to dispay?

3. When we select channel 1 as the trigger or to display we get an error
that says "Conditional Retrieval Er
ror."

TIA,

Pete

[Doug_Norman]

Hi Pete,

If you are in fact using the "Software Trig" version of this example, it should work if you enter 0,1 in the channels control and 0 in the trigger channel control.

However, your questions and error message make me think you might be using the "Hardware Trig" version of this example: "Acquire N - Multi-Analog Hardware Trig.vi". If this is the case you do have some restrictions to be aware of. Most important to you is explained in this quote from the description of that example:

"With E Series devices, if your analog trigger signal is connected to one of the analog input channels, that channel must be first in the scan list of channels. If you are using named channels, the trigger channel must be the first channel in the actual hardware channel o
rder, which may or may not be the first channel in the channel string control. This restriction does not apply if you connect the analog trigger signal to PFI0. Also, if pretrigger scans is greater than 1, you must either:
1. make your trigger channel and channel the same and only acquire from one channel.
2. use PFI0 as your trigger channel if you want to acquire from more than 1 channel."

It sounds like using PFI0 for your trigger input will solve your problem. If you need to also acquire your trigger signal, you could connect it to PFI0 and an input channel.

I hope this helps,

Doug

[PistolPete]

Thanks for the help Doug. Heres more info.

1. I'm using LV 6.1 and a DAQCard6024E with a Windows XP system. MAX is
the newest version so I think it is 6.9.2.
2. I'm trying to use the software trig version of the example at least that
is what the example is named.
3. The trigger line is attached to channel 0, I also tried PFIO, but had not
luck there either.
4. The example VI does work, and triggers properly the problem is that
channel 1 (i.e., the signal) is never displayed. We can see the trigger
just fine. The number of channels was set to 2 in in the lower right corner
of the VI.

TIAA,

Pete

"Doug Norman" wrote in message
news:506500000005000000D9700000-1017707437000@exchange.ni.com...
> Hi Pete,
>
> If you are in fact using the "Software Trig" version of this example,
> it should work if you enter 0,1 in the channels control and 0 in the
> trigger channel control.
>
> However, your questions and error message make me think you might be
> using the "Hardware Trig" version of this example: "Acquire N -
> Multi-Analog Hardware Trig.vi". If this is the case you do have some
> restrictions to be aware of. Most important to you is explained in
> this quote from the description of that example:
>
> "With E Series devices, if your analog trigger signal is connected to
> one of the analog input channels, that channel must be first in the
> scan list of channels. If you are using named channels, the trigger
> channel must be the first channel in the actual hardware channel
> order, which may or may not be the first channel in the channel string
> control. This restriction does not apply if you connect the analog
> trigger signal to PFI0. Also, if pretrigger scans is greater than 1,
> you must either:
> 1. make your trigger channel and channel the same and only acquire
> from one channel.
> 2. use PFI0 as your trigger channel if you want to acquire from more
> than 1 channel."
>
> It sounds like using PFI0 for your trigger input will solve your
> problem. If you need to also acquire your trigger signal, you could
> connect it to PFI0 and an input channel.
>
> I hope this helps,
>
> Doug

[C2]

Hi Doug,

I'm working with Pete for the project. Thanks for your reply. But my
question is if any of the E-series NI DAQ cards have the PFI0 I/O
connector. I can't find a connector named PFI0 in AT-MIO-16X card, or
there is a counterpart on the card. I had another post for the more
detailed description of the problem. Please read it at:

http://groups.google.com/groups?dq=ccomp.lang.labview&hl=en&group=comp.lang.labview&selm=df15148d.0204182159.3d09e9a1%40posting.google.com

Thanks a lot.

GC

Doug Norman wrote in message news:<506500000005000000D9700000-1017707437000@exchange.ni.com>...
> Hi Pete,
>
> If you are in fact using the "Software Trig" version of this example,
> it should work if you enter 0,1 in the channels control and 0 in the
> trigger channel control.
>
> However, your questions and error message make me think you might be
> using the "Hardware Trig" version of this example: "Acquire N -
> Multi-Analog Hardware Trig.vi". If this is the case you do have some
> restrictions to be aware of. Most important to you is explained in
> this quote from the description of that example:
>
> "With E Series devices, if your analog trigger signal is connected to
> one of the analog input channels, that channel must be first in the
> scan list of channels. If you are using named channels, the trigger
> channel must be the first channel in the actual hardware channel
> order, which may or may not be the first channel in the channel string
> control. This restriction does not apply if you connect the analog
> trigger signal to PFI0. Also, if pretrigger scans is greater than 1,
> you must either:
> 1. make your trigger channel and channel the same and only acquire
> from one channel.
> 2. use PFI0 as your trigger channel if you want to acquire from more
> than 1 channel."
>
> It sounds like using PFI0 for your trigger input will solve your
> problem. If you need to also acquire your trigger signal, you could
> connect it to PFI0 and an input channel.
>
> I hope this helps,
>
> Doug

[Doug_Norman]

Hello again,

Hopefully I can clear up a few things. E-series boards typically have the PFI0 trigger pin. The AT-MIO-16X is a legacy board and does not have this pin. It also does not do hardware analog triggering. However, it does support hardware digital triggering. For this you would connect your digital trigger to the EXTTRIG pin.

Regards,

Doug