custom pulse signal 9401

[charlie87]

Hi,

I am using NI 9401 and I would like to generate custom pulse signal which is generated in the loop. At the beginning the user determines the pulse sequence e.g. 

30 ms LOW, 20ms HIGH, 15 ms LOW, 25 ms HIGH 0.1ms LOW, .... Then I can programatically build the analog or digital waveform. Now I would like to use this waveform and generate the TTL signal. I would like to use the inbuilt counter as in this case here to be able to generate high frequency such as 1MHz etc..... any idea ???

[Zody]

Hi charlie87,

Normally, you wil be able to do that with counters, but you will have to change on the fly the new parameters, basically you can do it in the following ways:

1. You define a finite generation of signal with a specific duty cycle and number of pulses, and once it finishes you can reconfigure the task and start it again.
Disadvantages: You will have delays between one signal and another.
2. You can generate continuously signal with specific duty cycle and change on the fly the new parameters.
Disadvantages: You might have glitches, you will rewrite the new parameters in the middle of a period of previous signal.
3. You can define the digital waveform in LabVIEW and generate it with Digital Output - Hardware Timed.

I believe that the 3rd option fits the best your needs.

I am attaching a printscreen that can serve as a start for your application. 

Best regards,

IR