speed of incremental encoder

[DODI]

Hello!

I am using NI PCI -6251 and SCB-68 E SERIES DEVICES and LabVIEW 8.6.1 and have got incremental encoder which have A, B , Z signals.

I want to measure speed with DAQ. I used DAQ assistant (counter for measuring angular position) with 3 inputs

A signal (PFI 8)=37

B signal (PFI 10)=45

Z signal (PFI 9)=3

From DAQ assistant I get angle in radians or degrees or ticks.

I want to know how if DAQ assistant have some setting or .vi to measure speed with.

Or which will be the best way of measuring speed in Labview.

I also want to know how to get settings from DAQ assistant from the block in indicator. 

Thank you for your answers.

[Stefo]

Hi DODI,

If you are looking for the best ways to implement some operation with your M Series DAQ, then I would suggest M Series User Manual. On page 7-6 (112 in pdf) you can find for example one possible use of counter input - period measurement. In fact it is what you need to do - because to measure speed, you need to know the time between 2 pulses, or by other words you need to know how many pulses of known timebase occure. You also need to know the distance obviously - which shold be simple, as when you use incremental encoder, then you know how many pulses you get per 360deg (which means you know how many deg you have between 2 following pulses).

This means, that you can get speed by dividing distance (known from your encoder) with time (known timebase frequency * number of pulses).

I hope you didn't get lost

Unfortunately I don't understand the last question of yours: "I also want to know how to get settings from DAQ assistant from the block in indicator." Could you maybe clarify what you need here?

regards,

Stefo