Synchronization

[mishklyar]

Hello ,

   I need to create some kind of synchronization, and looking how to do it in a better way. I have two devices, AO 6733 and AI 6023E.

Now, one of the analog outputs should output the sine wave constantly , and without jumps in phase. The rest 7 analog outputs should

output on demand different values (every time the values are different ,also the time of generation may vary) and this output should be synchronized with analog input device,as a trigger for starting the acquisition

Michael.

[Jake_H]

So just to clarify - you have 1 constant sine output and you want the other 7 to output the value of that same sine wave whenever you push a button. At the same time that you push the button to trigger the On Demand event, you want the AI to start reading in values. Is this correct?

As far as getting started with synchronization of multiple functions/devices, I would recommend looking in the LabVIEW Help » Find Examples » Hardware Input and Output » DAQmx » Synchronization » Multi Device.

[mishklyar]

Jake H,

  Thank you for reply,

Just to clarify - the values of the 7 AO channels aren't necessary the sine, but some arbitrary values.

The main problem, in two words, only with analog output:

1) I need to output a constant sine on one channel .

And

2) To output an arbitrary values on the rest 7 channels on demand.

It may be seen as a parallel task...

The current solution I use: I am using a continuous generation scheme, and on demand updating the buffer with all 8 channels . 

But I am not very satisfied with it, because data size may vary and I need to keep a track of the sine wave phase, so that there is no

jumps.

I also tried to create a separate tasks for a sine channel and the rest 7 channels, but it failed, returning "the device is reserved"...

Michael

[Jake_H]

Michael,

You will not be able to create separate AO tasks on the same card without getting the "resource reserved error 50103" because the first task reserves the AO functionality. Without using separate tasks, you will have to decide which analog output is more important. Maybe you can have the sine wave generating in software and then sending a burst analog voltage when it sees a certain trigger.

As far as synchronizing your two devices, all you should have to do is share the same clock and a trigger source to make sure the AI and AO start at the same time and don't drift.