PLC OMRON C200HE
A PC (Programmable Controller) is basically a CPU (Central Processing Unit) containing a program and connected to input and output (I/O) devices. The program controls the PC so that when an input signal from an input device turns ON, the appropriate response is made. The response normally involves turning ON an output signal to some sort of output device. The input devices could be photoelectric sensors, pushbuttons on control panels, limit switches, or any other device that can produce a signal that can be input into the PC. The output devices could be solenoids, switches activating indicator lamps, relays turning ON motors, or any other devices that can be activated by signals output from the PC.
Because the C200HX/HG/HE PCs are Rack PCs, there is no one product that is a C200HX/HG/HE PC. That is why we talk about the configuration of the PC, because a PC is a configuration of smaller Units. To have a functional PC, you would need to have a CPU Rack with at least one Unit mounted to it that provides I/O points. When we refer to the PC, however, we are generally talking about the CPU Unit and all of the Units directly controlled by it through the program. This does not include the I/O devices connected to PC inputs and outputs.