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How to synchronize measument on diferent PXI-card

Hello,
 
We are using Labview8.0 and a PXI-System with PXI-6229, PXI-6232 and PXI-4351.
We want to start measuring analog inputs on the 3 cards at the same time and the same rate.
 
The questions are:
- How could we start the measurement at the same time?
- how could we sure the measures are done at the same rate (so that after one hour, all the card always measure at the same time)?
- how could we put the data together on the disk?
- Is there somewhere a tutorial upon synchronization with PXI?
 
Regards,
Risotto
 
 
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Hello!

Basicaly the PXI Bus (backplane) provides to share trigger and timing signals between the devices.

To do this, first you have to identify your PXI-System within the MAX (Measurement&Automation Explorer).

Then you can use the attached VI, which is a example for synchronize two AI, to build your application in the same way!

There are different ways to start AI synchronously, e.g for internal/external Trigger and to share clocks and rates, to get

sure they are running synchronously. You can search for examples under .../LabVIEWx.x/examples/DAQmx/Synchronization/MultiDevice.llb

Try the following example (for LabVIEW 8.x), if you have any questions further on, please post again!

 

Christian

 

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Also,
This tutorial is a good guide to learn about sync with PXI (Multi device sync section)
 
Data from each DAQ device can be stored in either a single common file or seperate individual files for each DAQ
 
PS: Christian, would the PXI synchronization availible for M series devices be compatible with with High precision data loggers( PXI 4351 in this case)  too ??
 
Message Edited by devchander on 08-22-2006 05:37 AM

Message Edited by devchander on 08-22-2006 05:46 AM

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Hi!

I'm sorry, i didn't kept the 4351 in mind while answering!

No, it's not possible to synchronize the 4351 via PXI, because it has no RTSI-Bus and only works with traditional DAQ.

So the only way would be to share the M-Series clock via a PFI Pin and try to use it as external trigger/timing for the 4351, but i didn't tried something like this!

 

Regards, Christian

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No, it's not possible to synchronize the 4351 via PXI, because it has no RTSI-Bus and only works with traditional DAQ.

Thanks Christian, that was my suspicion.

Also to start acq in sync with M series device, triggering AI acq from an M series device via one of the digital Input lines should be possible in this device, but not sure how close will it be to a PXI back-plane synchronised scenerio

Message Edited by devchander on 08-23-2006 01:38 AM

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