Does NIDAQ 6009 support clocked operation?

Hi,

I am using NIDAQ 6009 to output two analogue voltage. code followed:

"s = daq.createSession('ni');

addAnalogOutputChannel(s,'Dev1','ao0','Voltage');

addAnalogOutputChannel(s,'Dev1','ao1','Voltage');

outputSignal1 =  linspace(-0,1)';

outputSignal2 = linspace(-1,1)';

plot(outputSignal1);

hold on;

plot(outputSignal2,'-g');

xlabel('Time');

ylabel('Voltage');

legend('Analog Output 0', 'Analog Output 1');

queueOutputData(s,[outputSignal1 outputSignal2]);

s.startForeground;

"

but there is an error:' queueOutputData is disabled because the session contains channels that do not support clocked operations.‘

What should I do?

Regards

Xiaoran