7/20/2020 7:53 AM  
Joined: 2/8/2019 Last visit: 7/21/2020 Posts: 4 Rating: (0) 
I've used this algorithm to show RPM and it works great for me. Except, it shows double of the RPM value, so I have to change *60 in the block with *30 to show correct RPM. Not sure why this happen ?  
Last edited by: Jen_Moderator at: 07/21/2020 06:06:51New subject after splitting 

7/20/2020 8:01 AM  
Joined: 12/18/2014 Last visit: 8/11/2020 Posts: 19179 Rating: (2042)

From which algorithm speaks you? In this topic are different solutions.... 
7/21/2020 1:55 AM  
Joined: 2/8/2019 Last visit: 7/21/2020 Posts: 4 Rating: (0) 
similar to the program called "Speed_0BA8.Standard" in a post here. I've attached it. 
7/21/2020 4:31 AM  
Joined: 12/18/2014 Last visit: 8/11/2020 Posts: 19179 Rating: (2042)

Your calculation is wrong. rpm = revolutions per minute rpm specifies (for example with an axis of rotation) the number of revolutions in a time period in relation to this time period. My calculation: Number of impulses in one second (that's the gate time of the threshold switch (frequency) at my example multiplied by 60 (60s = 1min). 50 pulses per second multiplied at 60 = 3000 rpm. Your calculation: Number of pulses in three seconds (that is the gate time of the threshold switch (frequency) at your example multiplied by 30 and then divided by 3. That would be the number of pulses in 90s (1.5 min) divided by 3. Why you divide by 3 is beyond my knowledge, I can only guess. Division by 3 because you took 3 seconds to score?

7/21/2020 4:37 AM  
Joined: 2/8/2019 Last visit: 7/21/2020 Posts: 4 Rating: (0) 
I divided by 3, because the pulses are counting for 3 seconds duration. So the number of pulses counting x 1 min (60 sec) should be divided by 3. But it shows double of RPM should show. That's the reason I multiple by 30 (instead of 60) which is wrong and I know. 
7/21/2020 4:41 AM  
Joined: 12/18/2014 Last visit: 8/11/2020 Posts: 19179 Rating: (2042)

So you "bend" the evaluation as you need it. But I don't understand the background of your post. Who should benefit from this?

7/21/2020 9:44 AM  
Joined: 2/22/2008 Last visit: 8/11/2020 Posts: 1832 Rating: (135) 
The only possibility for your correction may be, that you get 2 impulses per rotation. Otherwise the calculation is wrong. By the way, it would be benefiting to use a proper time for better decimal representation. If you use 1s and multiply it with 60, you also can use 0.6s and multiply it with 100 or 6s and multiply it with 10. Then you don't get crooked numbers. Regards, Scorp 
Follow us on