1520 Filter bypass

[bsmyth]

The SCXI 1520 has programmable filter setting that I'm using successfully in LabView.  I'm simply entering the filter value in the channel property node and that works fine, EXCEPT when I'm trying to bypass the filter.  I assumed that unfiltered was programmed by putting a 0 in this property but it doesn't look like that is the case.  Instead 0 appears to be a 10 Hz filter.  All of the manuals say to program the filters using 10, 100, 1000, 10000, or it has a "bypass mode".  Nowhere does it say how to program the module for "bypass mode".  Maybe the default is "bypass mode" but the way I have it programmed I need to put something in that channel property.  What do I put in the channel property to set the filter to none?

Also, does the SCXI 1112 TC module have a filter bypass or is it a fixed filter?

Thanks,

Brian

[Donovan_B]

Hi Brian,

To bypass the SCXI-1520 lowpass filter in LabVIEW, you must use another property in the DAQmx Channel Property Node.  If you expand the Channel Property Node to reveal two properties, AI.Lowpass.CutoffFreq and another one below it, you can change the second property to Analog Input » General Properties » Filter » Analog Lowpass » Enable.  By setting this value to False, the SCXI-1520 lowpass filter will be set to bypass mode.  You can now use a control to bypass the filter or use the value that you set.

 

For the SCXI-1112, the 2 Hz lowpass filter is hard wired and therefore you cannot bypass it.

Message Edited by donovanb on 11-15-2007 01:51 PM

[bsmyth]

Thanks for the information, this looks very straight forward now that I know...

Thanks again!.