2 AO with delay

[scarface]

no worries guys.i have now fixed the problem.cheers for the help:)

regards

steve

[scarface]

hi tom,

sorry to come back to this again, but do you think it would be possible to set up the same program as you wrote before, but with two analog outputs (with a delay between both)?

regards,

stephen

[MarkLe]

Hi Scarface,

It's not as easy to setup the same thing in Analogue Output as all the channels run off the same clock - you need to setup the pattern(s) you want to output with the two channels out of phase, send the pattern down to the analogue output task then set the task running - then the patterns outputted on the two channels will be out of phase.

You can build this around the Continous Gen Voltage examples in the example finder, it's probably easiest to change to sending a 2D array of data to the AO task, generate this array with the 2 channels out of phase with each other, then start the task.

Hope this helps!

Mark

[scarface]

hi mark,

thanks for the help, but how would i do that?and surely i would need a 3D array (time, voltage, channel (even if there is only 2)), but is it possible to send a 3D array of data to the DAQmx write (analog ...) vi?

regards,

stephen

[scarface]

hi mark,

i've been playing about with the program again and realised how poorly i worded my last post.creating 2 waveforms that are out of phase would do most of the job nicely, however they still start at the same time (t=0).i need to somehow create a program that outputs 2 waveforms, with exactly the same parameters, starting the first at t=0 and then starting the second some time later.this time delay needs to be well defined and we need to be able to change it within the program.what would be the best way to do this?

i have thought about using triggers with the AOs, but i don't think this is possible as i think you're only allowed to use the create AO channel and write waveform vi's once at a time.

stephen

[scarface]

anyone?

[AdamB]

You might want to look here:

http://forums.ni.com/ni/board/message?board.id=250&message.id=27389#M27389

[scarface]

hi,

i'm trying to create a program that writes a finite number of samples from a waveform (created from a general digital waveform generator which i made- that works fine) to an analog output channel and then reads in the same number of samples through an analog input channel and saves all this data to file.however, when i run the program, it comes up with an error and says:

Read failed, because there are no input channels in this task from which data can be read.

can anyone suggest any possible solutions to this problem?

steve

[scarface]

here is the main program aswell (sub vi given before)

steve