Continous triggered Acquistion with NI-4060

[Tsquared]

I have an NI-4060. I need to make a continous periodic sample over a long period of time (say overnight). I would like to do this with an external trigger (as opposed to software timer) for better timing accuracy. I rather not have to re-initiate the acquisition everytime I want to make a measurement. Any suggestion on how to do this?

[Sonya W.]

Hello,

There is a shipping example which is installed with the NI-DMM driver which does exactly what it seems you are looking for (acquiring continuously, taking a sample each time an external trigger is received).

If you have installed the driver, the LabVIEW example program is located here:

C:\Program Files\National Instruments\LabVIEW 7.0\examples\instr\NIDMM\Triggers\Cont Acq Multiple Samples - Ext Trig - Ext Sample Trig.vi

Here is the documentation for the example which goes into further detail:

This example configures the DMM for a continuous acquisition. Each sample is acquired when a trigger is detected at the specified trigger source. Select the measurement function, range and absolute resolution. Specify the number of samples to acquire a
nd the trigger source. Enter the minimum number of samples to display at a time. The Initiate function starts the acquisition. A sample is acquired each time a digital-edge trigger is received. The Read Status function is used to determine how many samples are available. The samples are returned using the Fetch MultiPoint function. The acquisition is aborted when the Stop button is pressed.

I hope this helps!

Regards,

Sonya W.
Applications Engineer
National Instruments

[Tsquared]

Thanks, I tried looking at the example, but I don't have labview. I am using Labwindows/CVI, and I don't find an example for CVI.

On the other hand,
I was successfull in making a triggered measurment, but each time it triggers it reinitiates, which uses considerable time. It tried initating the meaurement with immediate, and using external trigger for sample trigger, but either that doesn't work or I am doing something wrong, because the measurement seems to return right aways without waiting for a trigger.

[Sonya W.]

Hello,

There are also nearly-identical examples for CVI. They are in a different location:

C:\Program Files\National Instruments\CVI70\samples\NIDMM\

The following article, located in the NI-DMM Help, describes each shipping example and notes which programming languages it is available in:

NI Digital Multimeters Help >> Search tab >> enter "examples" >> NI DMM Programming Examples

The following CVI shipping example seems closest to what you are looking to do:

C:\Program Files\National Instruments\CVI70\samples\NIDMM\Triggered\Cont Acq - Ext Trigs

I recommend running this shipping example with both Trigger Source and Sample Trigger set to External. "External" refers to the AUX I/O Connector on the DMM which it sounds like you
are using. I would not recommend using the "Immediate" trigger setting for your application. This causes the function to immediately proceed without waiting for any trigger.

This shipping example should give you a great jump start.

Regards,

Sonya W.
Applications Engineer
National Instruments