Using NI MAX
In NI MAX, you can enable the filter by creating an Analog Input task
for your DAQ device. Once you have created the Analog Input Task, select the Device
tab listed under Voltage Input Setup
. In this tab, you should be able to select the Lowpass Filter Cutoff Frequency that is offered by your device in order to enable the filter. Note:
You can use the DAQ Assistant
to use this task in LabVIEW.
In LabVIEW, you can enable the filter with a setting found in the DAQmx Channel Property Node in LabVIEW, located in the DAQmx Pallet. Navigate into the property tree to: Analog Input » General Properties » Filter » Analog Filter » Lowpass » Enable.
Note: In LabVIEW, you can find the default value of this property by following the steps below.
- Right-click on the property node and select Change All To Write. This will output whatever value is currently held by that property, which will be the default if nothing has been written to it yet.
- Duplicate the property node by holding CTRL and dragging your previous property node.
- Create an Indicator on the output to be able to display that value on your front panel. Below is an example image of the outcome.
Anti-Aliasing filters are often needed for communicating with sensors that experience high-frequency noise and in applications where frequencies above the Nyquist frequency are not of interest. For cards that do not have this filter, consider NI DSA (Dynamic Signal Acquisition) Boards
Analog triggers for M Series boards specifically can be put through one of the analog input channels on the board, or the APFI analog input trigger line. With the filter off, the analog trigger bandwidth is 700 kHz if the signal is wired through an analog input channel. If put through the APFI line, the analog trigger bandwidth is 5 MHz whether the filter is on or off.