Digital AI Filtering
- Updated2024-10-22
- 2 minute(s) read
Digital AI Filtering
The NI 4302, 4303, 4304, 4305, 4339, 4480, and 4481 modules have a user-configurable lowpass filter for their analog input channels. This filtering is implemented with a digital elliptical filter. It is configured independently of the tracking anti-aliasing filter. It may be helpful when measuring in an environment with excessive high frequency noise below the anti-aliasing filter's cutoff.
When sampling in hardware-timed single point mode, the filter is always enabled. You can set or query its cutoff frequency using the AI.DigFltr.Lowpass.CutoffFreq attribute/property. If your application does not require this additional filtering, leave this property set to its default value. This will configure the widest bandwidth filter possible.
Digital AI filtering for hardware-timed single point mode is supported on the following modules:
Modules | Default Cutoff Frequency | Support Cutoff Frequencies |
---|---|---|
PXIe-4302, 4303, 4304, 4305 | 2 kHz | 100 Hz, 200 Hz, 500 Hz, 1 kHz, 2 kHz, 3 kHz |
PXIe-4339 | 2 kHz | 200 Hz, 500 Hz, 1 kHz, 2 kHz , 3 kHz |
When using other sampling modes, the filter is optional. This filter can be enabled by using the AI.DigFltr.Enable attribute/property, and you can set or query its cutoff frequency using the AI.DigFltr.Lowpass.CutoffFreq attribute/property.
The following modules support digital AI filtering in other sampling modes:
Modules | Default Cutoff Frequency | Support Cutoff Frequencies |
---|---|---|
PXIe-4302, 4303, 4304, 4305 | None | 2 Hz, 20 Hz, 200 Hz, 1 kHz, 2 kHz, none |
PXIe-4480, 4481 | 2 MHz | 2 MHz, user-defined |