Programmable Controllers and IO Modules What are the similarities and different

programmable logic controller, ie PLC, can be considered a microcontroller or CPU + interface circuitry. Under normal circumstances, the microcontroller, CPU, including the IO module plc are just low-level output signal of a weak signal, you want to direct drive packed load is generally not possible, because their output current is too small, but because the PLC plus the interface circuit, you can put a weak signal amplification signal can directly drive high current take-load, general load current can be achieved PLC 1A.