Send Square Voltage Pulses to Elvis Board through daq toolbox

Hi Everyone,

I want to send a square pulse with dynamic duration [in the first run it is 0.5 seconds and then I want to change it to 2 seconds] using the digital I/O ports on elvisII board. I don't know how to incorporate time while I'm doing outputsinglescan. The following is the code I'm running. How can I know the ones which equal 5V are applied for how long and how to control it.

% Create a session

s = daq.createSession('ni');

% Add digital channels 0-->8

addDigitalChannel(s,'Dev1','port0/line0','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line1','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line2','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line3','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line4','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line5','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line6','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line7','OutputOnly');

addDigitalChannel(s,'Dev1','port0/line8','OutputOnly');

t = 1:10;

sw1_1 = ones(1,length(t));

sw1_2 = zeros(1,length(t));

sw1_3 = zeros(1,length(t));

sw2_1 = zeros(1,length(t));

sw2_2 = zeros(1,length(t));

sw2_3 = zeros(1,length(t));

row1 = ones(1,length(t));

row2 = ones(1,length(t));

row3 = ones(1,length(t));

step1 = [sw1_1' sw1_2' sw1_3' sw2_1' sw2_2' sw2_3' row1' row2' row3'];

step = step1(1,:);

outputSingleScan(s,step)

pause(7);

%Set them back to zero

sw1_1 = zeros(1,length(t)); sw1_2 = zeros(1,length(t)); sw1_3 = zeros(1,length(t));

sw2_1 = ones(1,length(t)); sw2_2 = ones(1,length(t)); sw2_3 = ones(1,length(t));

step1 = [sw1_1' sw1_2' sw1_3' sw2_1' sw2_2' sw2_3' row1' row2' row3'];

step = step1(1,:);

outputSingleScan(s,step)