Dasylab 2020 RPM measurement

[Cerdem]

Hi, Have a good evenings.

I am trying to figure out Dasylab for rpm measurement. I checked on the website, but could not find similar topics.

I have hollow shaft rotary encoder with 1024 PPR.

When i check the encoder with other applications, i can get pulse value like 1024 (and its multiples).

I could not understand how i can do that in the Dasylab.

I placed digital outputs (channel 0 and 1 for phase A and B), and counters, but i am not sure which options i should select for events to count.

Thanks.

 

[Fausto]

Hello @Cerdem.

Which daq hardware device are you using with DASYLab to acquire the signals?

Regards,

Fausto

[Cerdem]

Hi,

 

Labjack t7 pro

[Fausto]

LabJack is a 3rd party package and I do not have that device to troubleshoot.

I installed the LJM Library from LabJack and enabled the LabJack package in DASYLab's Configurator.  In DASYLab, I do see the LabJack modules group, but there is no Counter module as you showed in your previous post.  How did you access that 'Counter' module?

 

In your screen capture, select Rising Edges for 'Events to count' and then run your worksheet.

Regards,

Fausto

[Cerdem]

I actually chose it from the statistics section..

I have 2 phases (a and b). 

Should i choose rising edges for the second channel(phase b) ? or falling edges?

 

 

[Fausto]

Hello @Cerdem.

While the Labjack t7 pro device's digital I/O subsystem may support quadrature encoder inputs, the LabJack package for DASYLab does not support a quadrature decoder  feature.  With that in mind, you could count the rising edges of the encoder's phase A output over a given period to calculate a RPM, even if there's a change in direction.  However, determining position after a change in direction is a bit more complex to calculate.  The phase B output signal is used for determining direction.  Detecting rising edges should be the option selected for both signals, but if you're not concerned about position and only RPM, then the phase A signal is all you will need.

Regards,

Fausto

[Cerdem]

Hi, thank you for explanation.

I only need RPM. I picked rising edge.

Digital input(phase a) > Counter >

Should the next step to put formula for RPM and then display with chart recorder?

 

 

 

 

[Fausto]

Yes, after the Counter module, you will need a Formula Interpreter module followed by a Digital Meter display.