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

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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.

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Message 1 of 10
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You should count difference in counter values and divide it to period of measuring.

rpm.png

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Solution
Accepted by topic author stanm13

@Artem.SPb wrote:

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

rpm.png


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

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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).

 

  This is true. But I hope  stanm13 understands it 🙂
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Message 4 of 10
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Thank you very much. I understand now.

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Hi ,

 

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

 

Thank you !!!

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Message 6 of 10
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"feedback node", it's the same as shift register in loops

fb.png

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Message 7 of 10
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Thank you!!!

 

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

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Message 8 of 10
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The time between reading or time between counter increase

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Message 9 of 10
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I found the execution time for while loop in another post . Can I use this output as 'dt'?

 

Thank you!!

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Message 10 of 10
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