08-21-2014 03:47 PM
I am to generate two complementary digital signals using NI 9606 conected by RIO Mezannine Card to NI 9683 (Half Bridge DO).
I am able to generate the signals but I am not able to put dead time between high and low signal and also, low and high signal.
Requirement:
(1) When the first signal goes high and the second signal goes low, there should be a controllable dead time.
(2) Also when the second signal goes high and the first signal goes low, there should be a controllable dead time.
I am able to do requirement 1, but I am unable to fulfill requirement 2.
Please have a look at my VI and let me know how to go about satisfying requirement 2.
08-21-2014 06:00 PM
It would be helpful if you could draw a timing diagram of what you are wanting to do. The explanation does not give enough information, currently. This way, the community may be able to help you out.
There is also an example of PWM in the Example Finder that demonstrates using PWM if you search for "PWM".
08-21-2014 07:07 PM
I have attached the PWM timing diagram for reference.
08-22-2014 03:52 PM
Hello T@rminat0r
The signal 2 with dead time you described is a signal where the duty cycle was manipulated (PWM). Did you test the example Tannerite pointed?
Regards
Frank R.
08-22-2014 06:42 PM - edited 08-22-2014 06:45 PM
Hi Frank ,
I have already taken note of the example Tannerite has provided and have built my vi ( attached in previous post) surrounding that example.
Now I require to control the PWM duty cycle as you can see from the vi using a knob and that control refers to both the signal 1 and 2.
Now the signal 1 end and signal 2 generation requires a controllable dead time. Similarly, signal 2 end and signal 1 geneeration also requires another controllable dead time.
I am able to do either one dead time at a time using delay but not two dead time simultaneously.
I feel that I have two put the delays at the appropriate data flow point. I am working on that.
I would really appreciate if you could give some insight on how to solve this dead time issue and generate two complementary waveform with dead times whose duty cycle can be controlled by a knob controller in fronty panel .
I have also posted the required timing diagram for reference as suggested by Tannerite.
Best regards.
08-25-2014 05:53 PM
Hello T@rminat0r
That example you uploaded controls the duty cycle with the value we transfer to the loop timer, which controls the loop execution. If you need to implement signals with different duty cycles you need different loops. Have you tried to run loops in parallel (applying the solution you already have for one signal)?
Regards
Frank R.