Can we generate waveform simultaneously on two different channel (channel 0 and channel ) Using PXI 6711

[sharanu.dambal@geind.ge.com]

Can we generate waveform simultaneously on two different channel (channel 0 and channe 1 ) Using PXI 6711. If it is possible i am getting the error message while outputting the DC Waveform on the and channel .Generating sine wave on the channel 0 . The error message is "trnsferprogramIn error:A Transfer is already in progress for the specified resource or the operation is not allowed because the device is in the process of performing the transfers,possiblely with different resource". Pl help me with solution

Regards,

Sharanu

[AnujD]

Sharanu,

Thank you for contacting National Insturments support.

You should have no problem simultaneously generating a waveform on two different output channels on the 6711 within one application. You will get this error message if you try accessing the device using two different programs. You will also get this error if you fail to call the DAXmxClearTask function once you are done with a particular task.

To output to multiple channels, you can setup two channels using the DAQmxCreateAOVoltageChannel function. For example, for the chan input you can use Dev1/ao0:1

Hope this helps. Please reply back if you have any more questions.

Regards,
Anuj Dharia
Applications Engineering - NI

[sharanu.dambal@geind.ge.com]

Thanks for your input

We are using traditional DAQ for generating Sine wave and the DC wave form generation at the same time on ch0 and ch1 , Pl find the attachment for the code written for generating the DC and AC waveform with two different functions. Pl help with soultion

Regards

Sharanu

[GVanHorn]

With traditional DAQ to generate on two different channels at once you need to interleave the data that you want to write into one array.

For example, if you want to write data points 1, 2, 3 on channel 0 and then 4, 5, 6 on channel 1 then you will have to create an array with data points 1,4,2,5,3,6. The card will read indices DataArray(0), DataArray(2), and DataArray(4) for channel 0 and then the other points for channel 1. Then to let the card know that you are using two channels you need to add channels 0 and 1.

Hope this helps.

- Gerry