RPM in RS logix 5000

[ghost2go]

How do I measure rpm of a single pickup of a shaft with a prox

How would the ladder logic look like
Can i use a function blok

 

[jstolaruk]

Fast simple way (many variables that would impact accuracy though) is to have the pickup prox trip a counter and then a timer initiates a read-reset of the counter to get RPM.

 

[cwal61]

One thought is make sure prox has switching capacity of 5K Hz.
and if possibe I would put 180 degree cam on Shaft. A shaft spinning at 600 rpm is making one Rev. every 100ms with 180 cam you get 50ms pulse. I have attached 3 lines of logic to determine realtime RPM. I used RS5000 V17

 

[Jeff23spl]

looks like a student ssue again....why not telling us what you have tried so far ?
I can say to be carefull of your prox cycle VS plc scan time, you may have to use an high speed counter input.

Make some math to determine on many pulse you would get by second and check if youre scan time would miss some

 

[ghost2go]

Thanks cwal61 for the Sample will give it a go

Is there a Function Block that could do this??