USB - 6009, analog output, sample clock and continuous samples

[baobao]

Hi Labviewans,

i m trying setup an analog output channel with let say 10Hz sampling frequency (update rate). the daq i m using is USB - 6009 module. after creating task and virtual channel, i used the 'DAQ-mx Timing.vi - sample clock' to configure the sample mode (continuous sample) and sample rate (10 Hz). i chose sample mode of 'continuous sample' because i want to send a set data (sinewave data points for example) to the analog output. i want to output the sinewave continuously.

the following is the error out message i got when test running the vi:

Property Node DAQmx Timing (arg 1) in DAQmx Timing (Sample Clock).vi->DAQ AO setup.vi <append>
<B>Property: </B>SampTimingType
<B>You Have Requested: </B>Sample Clock
<B>You Can Select: </B>On Demand

<B>Task Name: </B>test

my question is: can we set the sample clock config for analog output channel on USB - 6009?

many thanks.. please help.

[Dennis_Knutson]

No, you can't. The inexpensive 6008 does not support clocked analog output. You can only do on demand timing and as the specs for the device states, the best you can get is 150 Samples/sec.

[Stuart_R]

That goes for the 6009 too.

On Demand timing is achieved through software timing i.e. using a DAQmx Write function inside a loop structure. By controlling the loop rate, you inturn control the update rate of the output. As Dennis pointed out, this is one of the limitations of the low-cost devices, a better option may be to use one of the USB M Series devices. Try contacting your local NI Sales team to see how they can help you get the right device.