146 Chapter 5 Digitizing
Viewing Sampled Data
The program on the following page plots digitized data to the controller’s
CRT (this particular program uses sub-sampling and the subroutine Plot_it
does the actual plotting). This program is helpful when developing digitizing
programs (especially when sub-sampling) since it allows you to see the data
being captured. Since this program simply draws vectors between the
samples (linear interpolation), it works well when the sampling rate is greater
than 10 times the frequency of the signal being measured. If the sampling
rate is less than 10 times the frequency of the input signal, this program will
plot an incorrect representation of the input signal. Figure 34 shows a typical
plot produced by this program.
Note The 3458 Option 005 Waveform Analysis Library is a software package
designed to capture and process digitized data. It contains routines that
initialize the system, capture data, compare data, compute parameters on
the data, perform Fourier transforms on the data, and plot/output the data.
Contact your Agilent Sales Office for more information.
10OPTION BASE 1 !COMPUTER ARRAY NUMBERING STARTS AT 1
20INTEGER Num_samples,Inc,I,J,K,L !DECLARE VARIABLES
30INTEGER Int_samp(l:l000) BUFFER !CREATE INTEGER BUFFER
40ALLOCATE REAL Wave_form(l:Num_samples)!CREATE ARRAY FOR SORTED DATA
50ALLOCATE REAL Samp(l:Num_samples) !CREATE ARRAY FOR SAMPLES
60Num_samples=1000 !DESIGNATE NUMBER OF SAMPLES
70Eff_int=2.0E-6 !DESIGNATE EFFECTIVE INTERVAL
80ASSIGN @Dvm TO 722 !ASSIGN MULTIMETER ADDRESS
90ASSIGN @Int_samp TO BUFFER Int_samp(*) !ASSIGN I/O PATH NAME TO BUFFER
100OUTPUT @Dvm;"PRESET FAST;SSDC 10;SWEEP ";Eff_int, Num_samples
Figure 34. Typical plotted waveform
To Next Page
Loading...
Need help?
General
