DO with 20MHz-division on DAQmx USB-6251

[xited83]

Hello everybody,

I haven't found a thread that matches to my problem. So here's my question and I hope that anyone can help me.

First of all I have to say, that I'm very new in LabVIEW.

I have to generate a special digital signal, which runs countinuosly to an SSI-Sensor (from an NI USB-6251 DAQ Board [*]). The generation of the signal is no problem and works well (both with the DAQ assistant and with DAQ vis). Until now Í have chosen the 100kHz timebase as Sample Clock Source.

But now I want to generate my DO (which is made up of 50 high states followed by 50 alternating high-low-states) with a frequency of 200kHz.

So here's my question:

- I think that I have to use the 20MHz timebase of the DAQ-board. How can I get a fraction of this timebase as sampling signal - especially how must I programm it?

- Is there any other way to program this?

Thanks for your time and help and sorry for my bad english,

Best Regards,

Simon

[*] I know that this isn't the perfect hardware for doing that, but I have no other possibility.

[Elmar_NI]

Hello Simon,

in this case its better to use one of the counter outputs.
You are able to create the high and low states by a pwm signal.
Please choose the DAQ Assistant "Signale erzeugen/Zähergestütze Ausgabe/Impulsausgabe".

Kind regards,

Elmar

[xited83]

Hello Elmar,

thanks for your reply.

I tried to use the clock signal for days when i started with this project. I was not able to make a signal which doesn't strictly alternate High and Low. But I need an signal, which consists from 50high states (dead-time) followes by 50alternating high-low states.

is there a possibility to generate this signal with counter (I didn't get it)?

Thanks,

Simon

[Elmar_NI]

Hello Simon,

please look at the example finder under hardware input output and select counter generation.
Or use the DAQ Assistant and select also counter for your outputsignal.
And you can select exactly the high and low time for your pulse signal.

Kind regards,

Elmar