analog output timed with loopback to analog input 6009

[Wojas]

Hello,

I have a question which is quite often touched on forums, helps and others, but nowhere finally solved.

My 6009 has 2 slow analog output ports, I would like to make loop with them.

start

send sinusoid n-level to analog output (in "on demand" mode)

pause 100ms

acquire signal on analog input (shorted with analog output)

back to start

I didn't find any solution how should I configure my signal express to work in generation/acquire mode. Because there is a lot of examples in labview - not in signal express.

Please send me hint.

[Maciej_Antonik]

Hi

We have discussed this issue on private emails, so I'll just post what we came to here, so that everyone knows it for the future. 

USB-6009 doesn't support hardware timed generation, so it's not possible to generate "N-samples" of a signal with it - you have generate 1 sample/iteration. See this KB: http://digital.ni.com/public.nsf/allkb/6F2C2B49A89D685C8625711D007BDD64

In order to do it you can do one of the following things:

1/ Start another application (i.e. made in LV) to keep generating samples in background

2/ Use DAQmx Generate step for 1 sample (on demand), but you need to make some logic, which would provide 1 sample of desired signal in every iteration.

Hope it helps. Let me know if you have any other questions.