Is there a guide out there with step by step instructions. Please share if available

I have tried both and find ladder logic more easy compared to the Function Blocks. Others may find the Function Blocks more easy to follow.

Rockwell Automation / Siemens / ABB / Yokogawa / Schneider .....

Should the plant networks be isolated or protected by Firewalls to make them secure. Often the plant networks also need some kind of health monitoring / trouble shooting by third-party remote system integrators. how could such access get enabled with plant security in place.

Having plc controls on pc based controls, seemed like a great idea at one time. why have they not become popular even in small plants and standalone systems.

Unlike computer systems that need regular patches, the PLC controller often are standalone or in isolated networks. They often get neglected when it come to upgrade projects in the organization and their operational life is often stretched much beyond their ideal lifespan. It is not uncommon in plan

Some of the names that can be listed like modbus, ethernet, fieldbus etc. How many else are out there and can there be a single one in the distant future.

With the erp systems increasingly offering connectivity to the plant floor automation, is there a need to go for separate MES packages. The ERP may also be able to offer similar analytics with some add-on applications.