simultaneous output

[DBoczkowski]

Hello,

I am using USB-6259 device with 8.7.1 DAQmx driver. I have written some code in C++ that allows to create the task with two analogue output channels. When the task is run there is no error but only first channel generates analogue signal. The second one doesn't seem to work at all. I know that all analogue outputs have common clock source. Is this a reason why the second channel is not supported?

It's hard to provide some code because of object oriented methodology, but if there is such need I will post it somehow.  

Regards,

Dariusz 

[Stefo]

Hi Dariusz,

Can you generate signal in MAX (Measurement and Automation Explorer)? If you are not able to generate signal in MAX, you can reinstall drivers, you can try your card in different slot or with different computer. Moreover, you didn't say what pins you use to measure on. Do you take the connection from MAX or from datasheet? MAX can be mistaken sometimes.

Let me know if you are able to generate output by MAX.

Regards,

Martin

[DBoczkowski]

Hello,

Thanks for reply. I try to generate signals on ao0 (pin 15) and ao1 (pin 31). The thing is they do work well separetely but when I want to add the second channel to the task, only first channel generates signal.

Regards,

Dariusz Boczkowski

[Stefo]

Hi Dariusz,

I believe you were able to try it from your code. Does the same happen when you use MAX to generate? What about different drivers. I'm asking those basic questions because drivers can contain some bug, for example. If you try different drivers, different computer and you will not be able to generate output on both outputs from MAX, then you might think about changing your device.

However, before you decide to send your device back, verify all possibile reasons which could cause incorrect behaviour.

Maybe one more question. What power do you try to supply? If it exceeds specifications, you can either burn output, or you will see incorrect output signals.

Regards,

Martin

[DBoczkowski]

Hi Martin,

I have checked the simultaneous generation in MAX and it worked fine for both outputs. Also everything is ok when I define Analoque Output Task with channel "ao0:1" and data buffer includes than data for two channels. But still when I want to define the task with only one channel e.g. "ao0" and then add the second channel "ao1" only one output is working although  DAQmxWriteAnalogF64 function writes data for both channels and returns no error.

Is it possible to have a more direct contact with you than via forum?

Regards,

Dariusz Boczkowski 

[Stefo]

Hi Dariusz,

That's good that your card is fine. Can you post simple code where you create task and add virtual channels, so I can take a look on code and try your example?

If you need better support than via forum, you might try to visit www.ni.com/poland (your name sounds very Polish ). You can find phone number and mail contact directly for National Instruments techsupport.

Regards,

Martin