SCC-68 Data Logging Frequency

[carleethian]

How fast can I sample the DAQ.  I'm taking 4 analog inputs and writing them to an ASCII via LabView SignalExpress.

I keep getting buffer overflow errors saying that the sample period is too short.  I'm currently at 20ms.

How short can I make it?  It seems a bit ridiculous that this thing can't sample at <50Hz.

[John_P1 · Accepted solution]

Hi carleethian,

The SCC-68 is the terminal block, which specific DAQ card are you using (likely a PCI card inside your computer)?  This would determine the maximum rate that you can sample at.  Are you using any SCC modules with the SCC-68?

Regardless of the exact DAQ card, you should be able to sample above 50 Hz.  What do you have configured as the Number of Samples input of your DAQmx Acquire Voltage step?  This should be high enough so that the SignalExpress loop can keep up with the data coming in from the DAQ card.  I usually shoot for about 1/5 of my sample rate to give a loop rate of 5x per second.

Best Regards,

[carleethian]

I got it finally.  I was single sample acquiring which caused it to slow down tremendously.

Continuous sampling is definitely the way to go.

Thanks for the help though.