on Apr 19, 2013Attached is a simple program showing how to digitize with the 3458A in Matlab. Data is sent directly over the bus, bypassing memory.
clear all; close all; clc;
dmm = visa('AGILENT','GPIB0::22::INSTR');
set (dmm,'InputBufferSize',400000);
set (dmm,'timeout', 25); %set the bus timeout for 25 seconds
set (dmm, 'ByteOrder', 'bigEndian');
fopen(dmm);
fprintf (dmm,'reset');
fprintf (dmm,'end always'); %sets up the correct EOL, use end on if using internal memory
fprintf (dmm,'id?');
id = fscanf (dmm);
id
fprintf (dmm,'preset dig'); %presets DMM for DCV digitizing (see page 218 of 3458A user's manual)
fprintf (dmm,'mem fifo');
fprintf (dmm,'dcv 10');
fprintf (dmm,'trig auto');
fprintf (dmm,'nrdgs 1000'); %set for 1000 rdgs per trigger
fprintf (dmm,'iscale?'); %get scale factor for sint format
scale = fscanf (dmm,'%f');
fprintf (dmm,'tarm sgl'); %Arm instrument once and begin triggering
[data] = fread(dmm,1000,'short'); %Read the data
scaledreadings = scale*data; %multiply alldata by proper scaling factor
plot(scaledreadings) %plot the data
scaledreadings %output to screen
fclose(dmm);
clear all; close all; clc;
dmm = visa('AGILENT','GPIB0::22::INSTR');
set (dmm,'InputBufferSize',400000);
set (dmm,'timeout', 25); %set the bus timeout for 25 seconds
set (dmm, 'ByteOrder', 'bigEndian');
fopen(dmm);
fprintf (dmm,'reset');
fprintf (dmm,'end always'); %sets up the correct EOL, use end on if using internal memory
fprintf (dmm,'id?');
id = fscanf (dmm);
id
fprintf (dmm,'preset dig'); %presets DMM for DCV digitizing (see page 218 of 3458A user's manual)
fprintf (dmm,'mem fifo');
fprintf (dmm,'dcv 10');
fprintf (dmm,'trig auto');
fprintf (dmm,'nrdgs 1000'); %set for 1000 rdgs per trigger
fprintf (dmm,'iscale?'); %get scale factor for sint format
scale = fscanf (dmm,'%f');
fprintf (dmm,'tarm sgl'); %Arm instrument once and begin triggering
[data] = fread(dmm,1000,'short'); %Read the data
scaledreadings = scale*data; %multiply alldata by proper scaling factor
plot(scaledreadings) %plot the data
scaledreadings %output to screen
fclose(dmm);