# Help calculating how fast an encoder is sending pulses

#### cgw94

Joined Jun 11, 2020
42
Hi all,

I am trying to get clarification on my calculations because they don't feel correct. I want to calculate how fast my encoder is pulsing.

For the info. I know my encoders resolutions 200 pulses per revolution and that my wheels circumference is exactly 1 foot.

I also know that the average speed is about 115 rpm. or 1.9rps. (lets round it up to 2 for sake of ease)
Here's my work:

2 rps * 200ppr =400 pulses per second. I then invert this to get how many seconds between readings. 1/400 = 0.0025 = 2.5ms/pulse.

So according to this I pulse every 2.5ms which will be sent to a PLC to be read. I believe this is fine?

I think ive just been staring at this too long! Thanks!

#### atferrari

Joined Jan 6, 2004
4,767
You are dealing with angular speed.

BTW, don't you have a way to measure the frequency of the outcoming pulses to see how far / close is your calculation?

400 pulses in 1 second.

Last edited:

#### jpanhalt

Joined Jan 18, 2008
11,087
2.5 ms per data word is slow. Don't worry about it.