Square Wave Generation FPGA

[Bharadwaz]

Hello ,

I am trying to generate a simple Square Wave signal to control frequency of LED blinking ( 0- 100 Hz)  via the FPGA of cRIO 9022.

When I am trying to control it on the host VI the maximum frequency attained was at between 40-50 Hz after that there is a decrease in rate of blinking even after increasing the frequency( 50Hz-100Hz the blinking rate was 50Hz -0 Hz).

I have tried using the normalize signal generation Fpga function .

tried changing the Data representation and the digits of precision and number of digits.

but of no use.

below attached are my host and fpga vis

What should i do to get a frequency more than 40 Hz ?I want to use this to automate the working of a Powertrain module.

[Matijas31]

Hi,

right click on your cRIO in your project Properties>>Top Level Clock. 

Are you looking for that ?

Best regards Matijas

[crossrulz]

Make sure the Execution Mode of your Square Wave Generator express VI is set to Inside of a Single Cycle Timed Loop.  Otherwise the code looks fine to me.

[Bharadwaz]

Hello ,

Thank you for the response Crossrulz and Matijas :).

Matijas, it was configured to run on the top level clock itself

Crossrulz, Yes it was made to run inside a SCTL by right clicking it and configuring.

My prolem was the data communication and conversion into FXP
When the Freq was 1Hz the fxp value was 2.49 e^-8 and for 100 Hz ( FXP 2.49xe^-6) the behaviour is same, so I was wondering whether the VI was missing the significant bits ?

[Bharadwaz]

Hello,

The problem was very simple, I was expecting a complex solution 😛 .It was the  period of the Deterministic loop in RT which was too long that frequency generator couldnt make it at higher frequencies, everything else was fine ( I was so dumb editing the ,Double, FXP , word length and integer length 😄 LOL )

Sorry for the late reply,

Just wanted to thank you guys for the support.

Cheers