Using USB-6008 software timimg Generate waveform

[DephinTW]

I am using USB-6008 device. Base on it's User Guide, this device on support software-timed and maximum update rate is 150 Hz.

By place a time delay VI for 1ms, I have a 1.660Hz sine signal. Is this wrong for place a time delay VI for software timing?

I would like to generate a 60 Hz signal by using software-timed VI on USB-6008 device. How should I do?

Thanks a lot.

[Ryan_V[DE]]

DephinTW,

The update speed of the USB-6008 is largely dependent on the speed of you computer as well as anything else on your USB bus. If you are using an older computer or have other USB devices on the bus, you may not achieve this rate. In order to output a 60Hz signal, the minimum output sampling rate is 120Hz. This corresponds to an 8.3 msec. delay between samples. Instead of using the "Wait" VI, you should try using the "Wait Until Next ms Multiple" VI. Place this in parallel with your generation. This will synchronize the output with multiples of the PC clock, rather than waiting for a fixed amount of time, irrespective of code and USB overhead.

Hope this helps,
Ryan V.
National Instruments