How do I get the speed (RPM) from the Encoder VI

[stanm13]

Greetings,

I have a two motors with quadrature encoders attached to them.

I am using the Encoder VI with the myRIO, which outputs two values - Counter value and Counter direction. From the counter value I am trying to display the speed (RPM). All the counter value does is is count up or down depending on the direction; I need a way to use these counts to measure the speed. I can't figure out how to do this?

Thank you in advance for your help.

[Artem.SPb]

You should count difference in counter values and divide it to period of measuring.

[ben64 · Accepted solution]

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@Artem.SPb wrote:

You should count difference in counter values and divide it to period of measuring.

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Not exactly, the result of the count substraction need to be divided by the number of encoder counts/rotation before being divided by dt (expressed in minutes).

Ben64

[Artem.SPb]

// Not exactly, the result of the count substraction need to be divided by the number of encoder counts/rotation before being divided by dt (expressed in minutes).

  This is true. But I hope  stanm13 understands it 🙂

[stanm13]

Thank you very much. I understand now.

[boga_vishnu]

Hi ,

You have used subtraction , division blocks . Can you tell me the name of that other block in the image?

Thank you !!!

[Artem.SPb]

"feedback node", it's the same as shift register in loops

[boga_vishnu]

Thank you!!!

If I put those feedback node in a while loop , what should be the value of " dt " ?? 

[Artem.SPb]

The time between reading or time between counter increase

[boga_vishnu]

I found the execution time for while loop in another post . Can I use this output as 'dt'?

Thank you!!