[Speed measurement]

speed test

Ok Damian, i have tested with a V280, it work fine!

I noticed after testing that you needed to divide from 300000.0 and not 30000.0

i have used 30000, and result is exact!

Thank you very much!

Fabio

[Speed measurement]

Hi Fabios,

Here is a reworked example.

I noticed after testing that you needed to divide from 300000.0 and not 30000.0

Let me know if you have an questions.

D

300000? why? 1000ms*60sec/2bolts = 30000

[Speed measurement]

Software test

Damian, please look image in the link "software test". I have only a doubt: MF2 (TimeBetweenPulses) remain ever > 0, also when the wheel is stop. Second your opinion is a good way to insert a timer (TD 1 sec) and ceck if for 1 sec no arrive impulse from I47 then MF2 = 0?

Regards

Fabio

[Speed measurement]

> Fabios, the previous posts were deleted because they contained a wrong approach, according to you.

Ok, no problem.

>I know you asked for a software solution, but it looks like the sensor is pointing to the nuts on the outside, and there are 8 of them. >This should help accuracy?

Ziwi, you are right. If i use 8 bolts i have more precision:

10(pulse in one second)*60(sec)/8(bolts)*2,34(ratio 433/1011) = 175,5 rpm

one pulse more:

11(pulse in one second)*60(sec)/8(bolts)*2,34(ratio 433/1011) = 193,05 rpm

It's no the best but it's better. There is only one problem.....it's no possible!

Damian your solution i like it! I study it and test! If i need help i will contact you, according to you!

Regards

Fabio

[Speed measurement]

> Also, as you shown before, if you take larger intervals the differences will be smaller (At the expense of accuracy).

Sure now is not accuracy.

Why now i don't see precedent post?

Regards

Fabio

[Speed measurement]

Hi,

i must measure the speed of a turbine. There is pulse sensor on a main wheel with 2 bolts. Every one rotary i have 2 pulse. I use an Hight Speed Input(I47/MI0).

The main wheel transmit the rotary to a more little secondary wheel. When the main wheel go to 433 rpm, secondary wheel go to 1011 rpm. Please see the two

attachments. As you can see i have used Frequency mesurement 1000 ms, so in MI0 i have F = impulse number in one second. If i multiply this number for 60 sec i obtain number of pulse in one minute. But now i must ti divide this number for 2 (number of Bolts(bulloni in italian). So as you can see in MI183 i have Main wheel RPM. If now i linearize from 433 to 1011, i obtain secondary wheel rpm. The system work fine, but i have the following problem:

for example if F(MI0) = 10 then speed of secondary wheel = 702 rpm; if F = 11 then speed of secondary wheel = 772 rpm; if F = 12 then speed of secondary wheel = 842 rpm; There is no middle way

So for my application is necessary more precision. Is there another more accuracy sistem via software?

Fabio

[Autotune does not start]

Hi,

my error! excuse me for the disturb.

Regards

Fabio

[Autotune does not start]

Hi,

i know that "Activate Autotune has any sense only in a real closed loop system, on real working conditions", but for test usually i check all on my desk. Now it happen that autotune does not start, status word remain = 0 and nothing happen. I have used many time autotune pid and it work fine.

I'd like to know: is there some condition that not permit to autotune to start?

Regards

Fabio

[I/O LC3]

Hi,

i must start up 2 I/O LC3. On the manual http://www.unitronics.com/Data/Uploads/IO_expansions/IO-LC1%20IO-LC3.pdf

on page 10 there is chart for Effective Resolution. Can you explain me this chart please?

Ciao

Fabio