Rif.: Ramp generation with DAQmx and Start Trigger on PFI0

[MatteoTonelli]

Hello,

I would generate an arbitrary voltage by setting the update period and the voltage values; the vi must include the generation start by digital edge on PFI0 of the DAQmx board (6015 usb).

At the moment my best results are attached (zip file with two VIs included). The first one (Trigger AI Acquisition_Tonelli_3ok.vi) works fine: by running the vi the generation starts immediately, the voltage steps are correctly updated according to the dt provided to the build waveform block.

The second version (Trigger AI Acquisition_Tonelli_3bad.vi) does not work; providing a digital rising edge on PFI0 (0-5V) the generation does not start and the vi results in a timeout error (Wait Until Done did not indicate that the task was done within the specified timeout).

The start trigger signal is privided by means of a digital output (a PXI module 6733) simply by setting the output in the test panel; the 6733 digital output is correctly connected to the PFI0 trigger input of 6015 board.

Question no.1:

In the first version (the working one) is the output time base derived from the board internal clock? In other terms, is the output voltage generated in a real-time way (not dependent on the OS scheduling)?

Question no.2:

Could you please help me to debug the second vi? Is it possible to generate the described output in order to obtain a real-time updating with a start trigger signal?

Many thanks,

Matteo

[LiciaP]

Hi Matteo,

for question n.1 I confirm that analog output is hardware-timed, since you have set the sample clock, thus the sample clock on the device is determing the samples output and not the OS.

For question n.2, 6015 should support digital start trigger for analog output. Can you check the output from 6733 with a tester in order to verify that 5V is seen at 6015 PFI0?

Bye,

Licia

[MatteoTonelli]

Thank you LiciaP,

the output from 6733 is correct (verified by means of oscilloscope) and it's correctly connected to PFI0 of 6015 board.

The same output and connection has been used as trigger in others VIs (as check) and it's works properly.

Matteo

[LiciaP]

Hi Matteo,

obviously you had also tried with other PFI lines, is that true?

What LabVIEW version and DAQmx version are you using? You can upgrade DAQmx in order to verify that DAQPad-6015 firmware is up-to-date.

Bye,

Licia

[MatteoTonelli]

Hello Licia,

Yes I also tried with other PFI lines.

Labview 2013, DAQmx 9.7.5.

Since the DAQpad 6015 is dated, I wold avoid any problem with software update. In the past I updated the NI-DCPower software and the updated version was not supported for my hardware.

What is the last supported DAQmx software version for DAQpad 6015?

Thank you Matteo

[LiciaP]

Hi Matteo,

also last DAQmx version supports DAQPad-6015, as stated in readme file.

It is not supported on 64-bit versions of Windows 8.x/7/Vista.

Bye,

Licia

[MatteoTonelli]

Hello,

the upgrade to the last DAQmx version did not resolve the problem.

The generation does not start with the PFIx edge.

Matteo