Unity Pro - DFB parameters

Hi Friends,
I`m new to schneider PLCs and unity pro software,and with a very good background in siemens PLCs. I want to know when I`m creating a user defined function block DFB, when to use the Inputs\outputs parameters and Public parameters? especially if I have variables resuted from the logic and they are written and read inside the block and I want them to be connected to Vijeo Citect.

Any ideas?

I use input/output for variables that need to persist between execution of the DFB, i.e. motor run hours. I put a motor run hours variable into the DFB, logic inside increases it while the motor is running, then the new motor run hours is output.

That's probably a terrible explanation but it's really the only time i use it for dfbs.

I have never had a need to use public variables so I'm not sure about those

Maybe this will help.




ETA: cant see the pic. In the Unity Help index, search for "public variable" and this will pop up. It explains the difference between public and private variables.

Thank you all..