siapth_veh

Hello everyone.

I would like measure with proximity sensor the RPM.

I have made programm but it is difficult for me to found the previous value in the OB30 (Cyclic interrupt), Cyclic time 1000 ms.

What must I change?

See attached.

Thank you,

Thodoris

 You need two different readings in a specified period. You will need another tag to keep track of the count from one interrupt to the next.

OldCount = SomeDint

CountNow = ID1000

CountPerPeriod = CountNow-OldCount

OldCount=CountNow

CountPerPeriod/1000ml = SpeedInPulsesPerPeriod (1000 miliseconds)

Then you do your conversion to get RPM

But it looks like you're using HSC to count periods so you can follow the example right here.

Kal.A

 

siapth_veh

Hello everyone.

I would like measure with proximity sensor the RPM.

I have made programm but it is difficult for me to found the previous value in the OB30 (Cyclic interrupt), Cyclic time 1000 ms.

What must I change?

See attached.

Thank you,

Thodoris

 You need two different readings in a specified period. You will need another tag to keep track of the count from one interrupt to the next.

OldCount = SomeDint

CountNow = ID1000

CountPerPeriod = CountNow-OldCount

OldCount=CountNow

CountPerPeriod/1000ml = SpeedInPulsesPerPeriod (1000 miliseconds)

Then you do your conversion to get RPM

But it looks like you're using HSC to count periods so you can follow the example right here.

 Thank you for all.