|NI-DCPower (English | Japanese)|
The NI PXIe-4113 supports aperture times based on the power line frequency of the device. The NI PXIe-4113 acquires samples at a fixed rate of 1/10500 s, a single period of a 10.5 kHz clock. When you set an aperture time to acquire a measurement, the NI PXIe-4113 acquires the number of samples that occur during the aperture time, averages the samples, then returns one measurement that represents the average reading over the specified aperture time. As a result, the aperture time must be a multiple of 1/10500 s. If you specify an aperture time that is not a multiple of 1/10500 s, NI-DCPower coerces the value to the next highest valid aperture time.
Use the niDCPower Configure Aperture Time VI or the niDCPower_ConfigureApertureTime function to set the aperture time of the device. Use the niDCPower Configure Power Line Frequency VI or the niDCPower_ConfigurePowerLineFrequency function to set the power line frequency of a specified channel of the device.
For information about how aperture time is related to acquiring measurements and triggering on the NI PXIe-4113, refer to NI PXIe-4113 Measurement Configuration and Timing and NI PXIe-4113 Triggers and Events.
You can reject power line noise from the signal by adjusting the aperture time.
To reject 60 Hz noise frequency from a signal, set the power line frequency to 60 Hz, set the aperture units to power line cycles (PLCs), and set the aperture time to 1.
To reject 50 Hz noise frequency from a signal, set the power line frequency to 50 Hz, set the aperture units to PLCs, and set the aperture time to 1.