Enhanced Alias Rejection

To avoid aliasing at low sample rates, some DSA devices support enhanced alias rejection. With enhanced alias rejection enabled, the device clocks the ADCs at a multiple of the user-specified sample rate. This results in an improvement in low-frequency alias rejection. With enhanced alias rejection enabled, you do not need to scale the desired sample rate, and you do not need to programmatically decimate data the device returns.

Enhanced alias rejection is controlled with the AI.EnhancedAliasRejectionEnable attribute/property. Enhanced alias rejection is enabled by default on NI 446X devices and disabled by default on NI 447X and NI 449X devices.

Note  The original versions of NI 447X devices do not support Enhanced Alias Rejection. Refer to National Instruments Dynamic Signal Acquisition Help for more information.

Synchronization Issues

When synchronizing multiple devices, set the AI.EnhancedAliasRejectionEnable attribute/property to the same value on all devices. If any of the synchronized devices do not support enhanced alias rejection, set AI.EnhancedAliasRejectionEnable to FALSE on all devices. When synchronizing devices from different categories, NI 446X with NI 447X for example, set AI.EnhancedAliasRejectionEnable to FALSE on all devices.