hello! i need help in PROFIBUS communication
How much of a "fluctuation" ?
Are the values completely different or very close ?
Is the Value shown on the LCP filtered? ( Yes, it probably is )
Are you looking at the right thing ? - Is the value on the LCP definitely the same item being sent over the PB link ?
> " how this is possible? "
You can expect the power to vary slightly. The LCP display is probably filtered a little so that you can actually read it instead of seeing digits flickering all the time.
> " and how to solve it? "
Is it really a problem ?
What sort of Drive ?
What sort of DCS ?
if you want to stop the value changing rapidly on the DCS, then filter it slightly ( say 2 seconds). After you read the data from the profibus, move it through a filter block and display the filtered value.
> "In DCS the raw value of KW is too much fluctuating."
What do you mean by "too much" ?
A small variation in Kw Load on a motor is normal. A large variation in Kw Load on a motor indicates that it might be speeding up and slowing down too often ( poor control by the DCS or poor tuning in the drive). Or it might mean that the load in the process is changing too much.
If you are sure that you are looking at the correct data on the profibus link, then this is not a "profibus problem" - the profibus is telling you what the motor is actually doing. The value shown on LCP is hiding the variation.
Otherwise, if the data on the profibus is completely wrong, then we need more information about what sort of drive and DCS you are using.
Firstly LCP you are referring is CDP on the drive or something else on control desk??
Have you selected the right variable in the 51 group "Profibus data", i mean the variable value of PZD out/in?
What PPO type you are using in the controller??
I prefer that u share Control builder hardware (online) and drive window (if not the CDP photo with power selected) together.