Hello, I have not found the answer in this forum yet. looking for the answer " how conveyors, robots, ovens, plcs all these different devices etc. communicating in the plant, and works smoothly.

 Can you help me to realize the bigger picture in automation...

 Regards.

hi,

a PLC is communicating with its devices via Profibus/Profinet. Therefore the devices get Input- and Output-Adresses, which can be used in the PLC-Program. 

When a PLC have to communicate to an other PLC there are much more possibilities. They can talk throw a coupler or connection or one PLC is a device of the other. Often the PLC´s don´t talk to each other directly. Each request goes to a higher level controller, which handles the communication.

Maybe the following manuals can give you an overview:

CPU-CPU Communication with SIMATIC Controllers

hope this helps,

regards,