1769 HSC Help needed with RPM

[riiska 0]

Hello Im using a 1769 HSC card with a L35E and trying to get the RPM. Ive been reading through forums for a couple days trying all the ideas from people who have had similar issues but I still cant get the current.rate(x) working.  Im using a single channel encoder at 60ppr. I believe the card is set up right and the channel is enabled. The counter seems to work fine but the rate stays 0 when im spinning the encoder slow but will jump to  100 or 200 if I spin it fast. 

Any help would be appreciated.

Thanks

[Elvin 2]

You can try to setup the encoder maximum count to 59, minimum to 0 and use that with some logic to calculate RPM.

I've never used current.rate but you can try setup the RPI smaller.

 

[Izzybe 13]

Do you have your input filtering enabled? Also, the encoders that I have used have a much tighter resolution than 60ppr :| (what are you using for encoder)

you need to calculate your scalar and then you calculate your rpm.

• f.e. Ctr0CyclicRateUpdateTime = 80
• CtrnScalar = 1 (you are not modifyling your raw data) --> 1000
• the encoder has 60 counts per revolution, and the change in Ctr[0]. f.e. CurrentCount is 12.
• Scalar = 60/60  [counts/revolution] /[sec/min] = 1 (nominator is your 60 ppr)
• RPM = (1000x12)/ (80x1) = 150 rpm  

Edited 17 Jul 2020 by Izzybe

[riiska 0]

Hello lzzybe, thank you for replying I know its been a while but im finally coming back to this project.  I do not have any filtering enabled. The encoder i am using is a Red Lion zfg0060c.

I left the Scaler at 1 because the manual says to get your scaler by dividing your ppr by 60(sec)  60ppr/60sec = 1.  The manual seemed to say that the HSC card would do the equation based on the scaler you put in and display the rate in the tag Ctr[0].current.rate. When I spin the encoder the current.rate stays a zero but will jump to 1000 for a quick second if I spin it fast but than go back to zero.