[NotInControl]

Originally Posted by Ether

In order to prepare a thoughtful analytical response, I needed to gather some technical information to clear up some ambiguities in your post.

But since you're in a hurry, I'll just ask you for clarification instead of taking the time to research it myself.

Not a problem, I am not really in a hurry, I am just curious, and as build season winds down your insight and viewpoint may show something we are overlooking when solving this problem, or an oversimplification we are applying which may be inaccurate for some reason.

I believe I have all bases covered but I won't know for sure until you share your perspective and reasoning. But I do appreciate you taking the time to formulate a complete answer... so thank you.

Originally Posted by Ether

When you use the term PPR, what do you mean by that? Do you mean the same thing that US Digital does (see attachment)? Or do you use the term PPR to mean what US Digital calls CPR?

GrayHill specs their encoders in CPR, not PPR, and they define CPR the same way that US Digital does.

So is your "256 PPR" GrayHill encoder 256 CPR or 64 CPR?

And is your "500 PPR" Cytron encoder 500 CPR or 125 CPR?

If you don't have this info, I will respond to your post without it, but my response will be in generalities and therefor less useful I would think.

I do not see an attachment with your post so it's hard for me to say how my definition lines up with US Digital however,

When I use the Term PPR, as in Pulses per revolution, I mean it in terms of the square wave being generated. A Pulse in my definition is a complete rising edge, width, and falling edge.

Therefore, if you are counting all rising and falling edges, a single pulse produces 2 counts.

If the encoder is quadrature, there are two digital outputs each generating its own pulse. Therefore if you were to count all rising and falling edges from a quadrature encoder, each pulse would return 2 counts but you have 2 pulses to deal with so the total is 4 counts.

So in my definition, a quadrature 500PPR, can produce 2000 counts per revolution when counting all rising and falling edges on both channels.

I believe GreyHill defines this as Cycles Per Revolution (CPR) which is another term used in industry but means the exact same thing as my PPR. I avoid using CPR because unless you are intimately familiar with the definitions you may confuse CPR to mean "Count Per Revolution" (or at least I would, and that is completely wrong).

So the GreyHill 256 Cycles Per Rotation encoder I mentioned would produce 1000 counts per rev if you were counting the rising and falling edge of each signal. or as I call it 256 Pulses per revolution (On a Single Channel).

Does that clarify things and answers your question?

Hope that helps,
Kev