LabVIEW

cancel
Showing results for 
Search instead for 
Did you mean: 

cDaq 9188 network - sampling rates

Hello:

 

I'm new at this. We have purchased a cDaq9188 with a bunch of modles (9205, 9184, etc), We are running DaqMx

 

I have created a .vi that just reads the channels, converts them to an EU via a linear graph (y=mx+b), and then displays the data. The data can also be stored in an excel spreadsheet. I have included the .vi

 

I can't get any better than 1 sample per second. If I am just running one or two modules, I can add the sample clock timing in the programming, but  cannot get it running any faster than 1 S/s. Could this be the network? On the network, we are just running a cheap network switch at 10BaseT. I noticed this because we purchased the cDaq usb version and I have to put in the timing as it runs a lot faster.

 

Any help or suggestions would be appreciated.

 

The MR2-SF file is the main file. The Linear (subvi) file is just the linear equation to convert from raw voltage to EU.

 

Thanks

Chris 

Download All
0 Kudos
Message 1 of 2
(2,323 Views)

Are you logging data when it only works at 1Hz (Collect Data = True)?  Maybe the writes are slowing you down.

I didn't download the linear subVI, but if it takes a long time to run that could slow you down.  Is it set to reentrant so that you can have multiple versions of it execute at once?

 

The most likely cause is in your Daq code.  You don't seem to use the DaqMX Timing.vi anywhere.  This lets you set and control your sample rates.  It's possible that one of your daq channels is defaulting to only reading at 1Hz.  You might be able to figure out which one(s) it is by setting the timeout on the Read VIs to have a timeout of zero.  Then you can see which ones return no data on most loops.

0 Kudos
Message 2 of 2
(2,309 Views)