VTI Instruments EX1000A, User Manual

Page: 241 / 320

www.vtiinstruments.com
EX10xxA Function Calls 241
vtex10xxA_set_filt_freq
F
UNCTION
P
ROTOTYPE
ViStatus_VI_FUNC vtex10xxA_set_filt_freq(ViSession vi , ViInt32 channels[] ,ViInt32 numChannels , ViReal64
filt_freq );
F
UNCTION
P
ARAMETERS
vi = contains a session handle to the instrument. This handle is obtained by the function and remains valid until the
session is closed.
channels[] = the list of channels to which to apply the filter frequency selection. The list of channels can include
channels not currently in the scan list and can be a subset of the channels in the scan list. Valid input values:
0 through 47.
numChannels = the length of the channels array. Valid input values: 1 through 48.
filt_freq = a real output value representing the frequency setting in hertz (Hz). Valid input values: 4, 15, 40, 100,
500, and 1000.
D
ATA
I
TEM
R
ESET
V
ALUE
filt_freq = 4.0 (for all channels)
D
ESCRIPTION
This function sets low-pass filter cutoff frequency of specified channels. Supported frequencies are 4 Hz, 15 Hz,
40 Hz, 100 Hz, 500 Hz, and 1 kHz. If a value other than the valid frequencies are used, this function round up to the
next highest valid frequency. If a number greater than 1000 is used, the filter is set to 1 kHz.
NOTE For the EX1048, the only available frequencies are 4 Hz and 1 kHz.
E
XAMPLE
// set channels 0-4 for 4 Hz
ViInt32 low_channels[5] = { 0, 1, 2, 3, 4 };
vtex10xxA_set_filt_freq(vi, low_channels, 5, 4.0);
// set channels 5-8 for 1 kHz
ViInt32 high_channels[4] = { 5, 6, 7, 8 };
vtex10xxA_set_filt_freq(vi, high_channels, 4, 1000.0);