generate a swept sinusoid using visa and capture waveform using quick-凯发k8网页登录

requirements

this example was tested using a keysight technologies® 33522b function generator and a tektronix® tds 1002 oscilloscope. the gpib addresses of the function generator and oscilloscope are gpib0::5::instr and gpib0::11::instr, respectively. the function generator is configured to generate a 2v p-p swept-sinusoid (20 to 200 hz) with an offset of 1v every 100 ms on channel 1. the oscilloscope is configured to acquire a waveform on channel 1.

configure the oscilloscope

configure the oscilloscope using a quick-control (oscilloscope).

scoperesource = "gpib0::11::instr";
ch = "ch1";

create an oscilloscope object and open a connection to the instrument.

scope = oscilloscope;
scope.resource = scoperesource;
connect(scope)

the autosetup function automatically adjust channels, vertical, horizontal, and trigger controls based on connected signals.

autosetup(scope)

enable and configure channel 1.

enablechannel(scope,ch);
configurechannel(scope,ch,"verticalcoupling","dc")

configure the channel to display at 1 volts/div.

configurechannel(scope,ch,"verticalrange",1)

set probe attenuation to 1x (options include 1, 10, 100).

configurechannel(scope,ch,"probeattenuation",1)

the acquisitiontime property represents the waveform duration in seconds. setting the acquisitiontime will change the sec/div control accordingly. acquisitiontime typically corresponds to 10 divisions (or one screen of data).

scope.acquisitiontime = 0.25;
scope.triggerlevel = 2.56;
scope.triggersource = ch;
scope.triggerslope = "rising";
scope.triggermode = "normal";
disp(scope)

oscilloscope: tektronix,tds 1002
   instrument settings:
      acquisitionstartdelay: 'not supported'
            acquisitiontime: 0.25 s
               channelnames: 'ch1', 'ch2', 'math', 'refa', 'refb'
            channelsenabled: 'ch1'
            singlesweepmode: 'off'
                    timeout: 10 s
             waveformlength: 2500
   trigger settings:
               triggerlevel: 2.56
              triggersource: 'ch1'
               triggerslope: 'rising'
                triggermode: 'normal'
   communication properties:
                     status: 'open'
                   resource: 'gpib0::11::instr'
lists of methods

configure the function generator

configure the function generator to generate a sweep waveform using a visa-gpib object.

fgenresource = "gpib0::5::instr";
vfgen = visadev(fgenresource)

vfgen = 
  gpib with properties:
         resourcename: "gpib0::5::instr"
                alias: "fgen_2ch"
               vendor: "agilent technologies"
                model: "33522b"
           boardindex: 0
       primaryaddress: 5
     secondaryaddress: 65535
    numbytesavailable: 0
  show all properties, functions

configure the sweep amplitude and offset.

writeline(vfgen,"sour1:volt  1.0")
writeline(vfgen,"sour1:volt:offs  1.0")

enable sweep mode.

writeline(vfgen,"sour1:freq:mode swe");
writeline(vfgen,"sour1:swe:stat on");
writeline(vfgen,"sour1:swe:spac lin");

configure the start and stop frequencies.

fstart = 20;
fstop = 200;
writeline(vfgen,compose("sour1:freq:star %d",fstart));
writeline(vfgen,compose("sour1:freq:stop %d",fstop));

configure the time taken to sweep from the start frequency to the stop frequency as sweeptime.

sweeptime = 0.1;
holdtime = 0;
returntime = 0;
writeline(vfgen,compose("sour1:swe:time %0.1f",sweeptime));

configure time to remain at the stop frequency as holdtime.

writeline(vfgen,compose("sour1:swe:htime %0.1f",holdtime));

configure the time required to return to the start frequency as returntime.

writeline(vfgen,compose("sour1:swe:rtime %0.1f",returntime));

configure the trigger.

writeline(vfgen,"trig1:slop pos"); 
writeline(vfgen,"trig1:sour imm");

acquire the waveform

acquire waveform data using the oscilloscope. the acquisitiontime property represents the waveform duration in seconds. the waveformlength property represents the number of points in the waveform data.

y = readwaveform(scope);
t = linspace(0,scope.acquisitiontime,scope.waveformlength);

plot the waveform

plot(t,y)
ylim([0.5,3.5]);
title("acquired waveform (sweep)")
xlabel("time (s)");
ylabel("voltage (v)");

clean up

clear the workspace when you are finished.

disconnect(scope)
clear scope vfgen