In shortA PLC (programmable logic controller) is an industrial computer that reads input signals and drives outputs through a cyclically executed program to control machines and processes.
In each scan a PLC reads inputs (sensors, switches), runs the user program and updates outputs (valves, motors). Reliability and responding within a defined cycle time set it apart from general-purpose computers.
PLC data is reached with vendor-specific protocols or standards such as OPC UA. In integration projects tag names, data types, units and when counters reset matter as much as the connection itself.
In OPC Router projects
PLC data reaches OPC Router through OPC UA or suitable plug-ins; driver scope is confirmed in the project.