Whenever I change many values on the HMI quickly, the screen freezes for a few seconds.
Is this normal or a communication problem?
This happens when the HMI and PLC communication gets overloaded.
If many tags refresh at the same time, it causes delays.
Other reasons include:
Slow communication protocol
Too many screens updating at once
Large data blocks being read frequently
Reducing update rate or splitting tags across screens usually fixes the freezing.