© National Instruments Corp. 19 NI 9237 Operating Instructions and Specifications
rate. The stopband rejection is the minimum amount of attenuation
applied by the filter to all signals with frequencies within the
stopband.

Alias-Free Bandwidth

Any signal that appears in the alias-free bandwidth of the NI 9237
is not an aliased artifact of signals at a higher frequency. The
alias-free bandwidth is defined by the ability of the filter to reject
frequencies above the stopband frequency and equals the data rate
minus the stopband frequency.
Understanding NI 9237 Data Rates
The frequency of a master timebase (fM) controls the data rate (fs)
of the NI 9237. The NI 9237 includes an internal master timebase
with a frequency of 12.8 MHz, but the module also can accept an
external master timebase or export its own master timebase. To
synchronize the data rate of an NI 9237 with other modules that use
master timebases to control sampling, all of the modules must
share a single master timebase source. Refer to the software help
for information about configuring the master timebase source for
the NI9237. Visit ni.com/info and enter cseriesdoc for
information about CSeries documentation.