Figure 12 shows the passband at one data rate.
Figure 12. AC cutoff frequency response
Stopband
The filter significantly a enuates all signals above the stopband frequency. The primary goal of the filter is to
prevent aliasing. Therefore, the stopband frequency scales precisely with the data rate. The stopband rejec on
is the minimum amount of a enua on 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 WebDAQ 504 is not an aliased ar fact 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 it is equal to the data rate minus the stopband frequency.
Logging data
You can log up to 3 GB of data to internal WebDAQ storage. To generate larger data files, log data to external
media with a storage capacity suitable for the acquisi on. USB drives and SD cards are available in different file
formats, and OS support for each format varies. WebDAQ supports FAT32, exFAT, ext2/3/4, NTFS file systems.
When genera ng large data files with Windows or Mac, or transferring files between opera ng systems, we
recommend using external media forma ed with the exFAT file system, such as an SDXC memory card. When
running Linux, use external media forma ed with the ex2/ex3/ex4 file system. Refer to the WebDAQ help FAQ
for more informa on about file formats.
File too large error
If you generate data that exceeds the capacity of the selected storage loca on, a "File too large" error is
returned and the acquisi on stops. To avoid interrup ons, select a storage loca on with a large capacity.
WebDAQ 504 User's Guide
page 16
