Synchronizing 4 SCXI-1140 Modules

[avasque2]

I need to synchronize 4 SCXI-1140 modules connected to two PXI6040E and two PXI6070E on a PXI-1010 chassis with a PXI-8184 Embedded controller. Ideas?

[Nathan_R]

Hi avasque2,

To have an E-Series DAQ card control each SCXI-1140 and then synchronize them you will need to do several things. The first is to set each SCXI-1140 to communicate in parallel mode. This will allow each of the DAQ cards to sample from one of the SCXI-1140’s. Each of the DAQ card will need to be wired to the back of the SCXI module it is sampling from. One of the DAQ cards will also be the controller for the chassis. Some instructions for setting this up can be found here.

Once the chassis is configured you will then need to sync the four DAQ cards. This can be done by have one of the four cards generate the sample clock and start trigger and share them through the PXI backplane. The other three cards will use the sample clock and start trigger to stay synced. An example and explanation of how to do this can be found in the Developer Zone article, M Series Synchronization with LabVIEW and NI-DAQmx. Since you are using E-Series DAQ you will want to look at the section towards the bottom of the article titled, An Alternative Method: Synchronization by Sharing a Sample Clock.

Please let me know if you have any questions.

Thanks,

[avasque2]

Nathan,

Thank you for your help.  Your information was precisely what I needed, and I learned much from the articles you led me to.  Thanks again.

[avasque2]

Now that I have everything synchronized I need to display the 32 channels that I have acquired.  How would you go about displaying 8 or 10 waveforms with the ability to choose which channels you want to display on the graphs.  I am sure this is fairly simple, but I am just a beginner and can't find the option.

[Pakman]

Hi avasque2,

Attached is a simple example that demonstrates how you can dynamically change which channels are displayed on a waveform graph.  You can also modify this VI to only allow static changes prior to graphing.  To do this, simply move the FOR loop outside of the While loop and delete the array initialization procedure.  Let me know if you have any questions!

[avasque2]

I forgot to mention I have LabView 7.0 Express, could you save it in this format instead.  Thank you sorry

[avasque2]

...or even a screen shot jpg would help.  Thanks again

[Pakman]

Hi avasque2,

Unfortunately, I do not have DAQmx support installed for LabVIEW 7.0, so here are the screenshots:

Front Panel while running:

Block Diagram:

Message Edited by Pakman on 06-17-2008 01:09 PM

[avasque2]

I built the diagram using labview 7, but I am having trouble creating the indicator coming out of the for loop.

[avasque2]

I mean the Control into the FOR loop