Could you tell me please -
How does the mathematical formula look like for your case?
What is the ratio between encoder pulse distance and motor revolution?

For more code related study material - [LINK]

Saidi S

is that correct ? 

I do not know.
How does the hardware configuration look like?
Screen capture pictures will be most welcome.

Saidi S

Yes you right i'm a student and i am doing my best ! 

I have 200 pulses per revolution and i need to transform these pulses in rev/min in my program. My hsc count the frequency of my encoder.

With these frenquency, i do that :  (frequency*60)/200 and this give me the rev/min.

So it's ok , it's work ! 

Thank you very much for your time and sorry for inexperiment ! 

Hi.

Realise that Mr Jeff and I could just have said all is okay,
leaving you to realise your own 'mistakes'.

For the best results we must know what you know
..relating to the application.
It is up to you to give us eyes and ears.

As this is not a scolding, I spell it out for you:
* Where is the encoder mechanically connected?
* Which PLC is used (part number or full description including firmware version)
* Which engineering software?
* How is the encoder electrically connected to the PLC?
* How is the encoder signals configured in the software?

I have tried to avoid asking the very details
by asking the hardware configuration.
Applied to what you ask - it is the part where you configure the HSC (high speed encoder).
I need all of that section - not just partial.

The trouble is...
- Quadrature action has 4 counts for each pulse.
- The 'frequency' count mechanism is measured over a preset time.
It may be 5 counts over 2sec for example so that is 2/5Hz not 1/5Hz.

Have a look at my comments and see what helps.

Best regards.