Acqiris U5309A User Manual page 23

transfer and mainly on the PCIe connection and PC multitasking activity..
The time to initiate the next acquisition.
A solution to reduce the time between averaging sequences, is to combine AVG and TSR modes. See
Averager with triggered simultaneous acquisition and readout (AVG/TSR option) (page 39)
details.
Noise suppressed accumulation (NSA)
In some applications, such as time-of-flight spectrometry, the signal is a rare event sitting on top of a
noisy baseline and the averaging process reduces the random noise.
As a consequence, to enhance the acquisition card ability to detect such signals in the presence of
synchronous noise, the averaging firmware allows the user to set a Threshold that must be exceeded
for each data value to be entered into the sum. Furthermore, the noise base can be subtracted from
each data value above threshold before the accumulation is done (See Figure below). The noise base
should always be equal or smaller than the threshold.
Figure 2.4 - Signal detection using noise suppressed accumulation.
It is possible to use the NSA on negative polarity pulse. By enabling the channel data inversion
capability, the signal will be inverted before applying the NSA settings. See
Parameters:
Enabled: Specifies whether the noise suppressed accumulation is active. This attribute affects card
behavior only when the acquisition mode attribute is set to averager.
Threshold: Specifies the threshold of the noise suppressed accumulation. Each data value must
exceed the threshold value to be entered into the sum. This parameter is defined per channel in ADC
counts. It can be configured in the range [0 to 255] .
NoiseBase: Specifies the noise base value for the noise suppressed accumulation. The noise base
is subtracted from data values which are higher than the configured threshold. This parameter is
defined per channel in ADC counts. It can be configured in the range .
U5309A User's Manual
2.4 Real-time averaging (AVG option)
Data inversion (page
section for
1).
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