proportional valve PWM to voltage

[wew044]

Hi All,

I have the following equipment:

1. proportional valve - https://www.aliexpress.com/item/33040257963.html

2. Frequency converter - https://www.amazon.com/KNACRO-Frequency-Voltage-Conversion-Converter/dp/B06XZFKPHP/ref=sr_1_fkmr0_2?...

3. NI9201 for reading voltage inputs

4. NI9263 for sending voltage outputs (to the porportional valve).

This valve is capable of sending PWM outputs, and I am trying to convert that to DC voltage so it can be read by NI9201 (please see attached picture). I expect that when I move the ball valve, the output frequency from the valve will change, which then be converted to DC voltage. After the connection has made, labview is picking up a voltage signal 4-5V.  However, when I change the  position of the ball valve. labview is still reading the same 4 to 5V signal. 

Does anyone have any idea what would be the issue? 

Note. I have not calibrated the converter, but this should not be the reason why it is not picking up the changes in signal.

Thanks!

[JB · Accepted solution]

According to its specifications, the output signal frequency of the proportional valve can be adjusted.

By cons it is not the frequency but the duty cycle of the signal that changes with the position of the valve.

That's why you have to use a PWM to voltage converter.

[wew044]

I was beginning to have doubt about this PCB as well as the manual did not really mention anything about PWM.

Much appreciated for the response!