how to change a sampling rate of a agilent function generator 33220a using matlab visa?

I am interfacing a function generator (Agilent 33220a) using matlab visa to generate an arbitrary waveform (a chirp). The waveform is generated. However, I want to reduce the sampling frequency. This is required to increase the sweep time of the chirp. The current sampling rate of 50Mbps generates a maximum sweep time of 500sec. The code is given below-

if true
  % code
%opens and creates a visa session for communication with function generator

fgen = visa('AGILENT','USB0::0x0957::0x0407::MY44048510::0::INSTR'); set (fgen,'OutputBufferSize',100000); fopen(fgen);

%Query Idendity string and report fprintf (fgen, '*IDN?'); idn = fscanf (fgen); fprintf (idn) fprintf ('\n\n')

%Clear and reset instrument fprintf (fgen, '*RST'); fprintf (fgen, '*CLS');

% Create arb waveform with 8192 points of 0-1 data fprintf('Generating Waveform...\n\n')

    sRate = 100;

    ch = [];
    for t = 0:1/sRate:10
        c = sin(t);
        y = num2str(c);
        s5 = sprintf(', %s',y);
        ch = [ch s5];
    end

    %combine all of the strings
%     s = [rise width fall low];
        s = [ch];

    % combine string of data with scpi command
  arbstring =sprintf('DATA VOLATILE %s', s);

%Send Command to set the desired configuration fprintf('Downloading Waveform...\n\n') fprintf(fgen, arbstring); %make instrument wait for data to download before moving on to next %command set fprintf(fgen, '*WAI'); fprintf('Download Complete\n\n')

%Set desired configuration. fprintf(fgen,'VOLT 2'); % set max waveform amplitude to 2 Vpp fprintf(fgen,'VOLT:OFFSET 0'); % set offset to 0 V fprintf(fgen,'OUTPUT:LOAD 50'); % set output load to 50 ohms fprintf(fgen,'FREQ 1'); %set frequency to 1KHz fprintf(fgen,'DATA:COPY TEST16385, VOLATILE'); fprintf(fgen,'FUNC:USER VOLATILE'); fprintf(fgen,'FUNC:SHAP USER');

    %Enable Output
    fprintf(fgen,'OUTPUT ON'); % turn on channel 1 output

% Read Error fprintf(fgen, 'SYST:ERR?'); errorstr = fscanf (fgen);

% error checking if strncmp (errorstr, '+0,"No error"',13) errorcheck = 'Arbitrary waveform generated without any error \n'; fprintf (errorcheck) else errorcheck = ['Error reported: ', errorstr]; fprintf (errorcheck) end

%closes the visa session with the function generator fclose(fgen); end