Create a RPM on Micro820 with normal input

[cwal61]

You can measure the time between each pulse. It takes 3 rungs of logic.

Rung 1. Use your input to one shot an OTE.
Rung 2. XIC of OTE Move Timer.ACC into a Storage DINT. Then Divide 60000 by Storage DINT and place in a Display DINT.
Rung 3. XIO of OTE Run Timer.

This will give you a Real Time RPM in your Display DINT.

edit: As long as your input is on for 2 scan cycles of the PLC then you will not miss any RPM values.

 

[MrDeeply]

Derived from the problems and the little use of AB, I go the other way using analog signal directly from the frequency variator. It will be more work, due to the calculations of transmissions and ratios, but more reliable.

Because I need to have a ton/hour sampler. So it's just a matter of resorting to good math and applying it to automation.

Thanks for all the support, I will still come back to this approach in the future, because if it works on siemens, it also has to work on AB.

Thanks.