Controllers with programmable logic. Depending on the devices to be switched on or off, the output ports of a PLC are relay or opto isolator with transistor or triac. In most cases, a digital signal from a PLC's output channel is utilised to drive an actuator, which in turn controls a process.
In a PLC system, inputs and outputs are normally separated into separate modules. The state of input signals such as pushbuttons, switches, temperature sensors, and so on is detected by an input module. Relays, motor starters, lights, and other devices are controlled by output modules.
Several manufacturers produce these little devices in a standard physical size and shape, and the makers of larger PLCs brand them to fill out their low-end product range. There are typically 8 to 12 discrete inputs, 4 to 8 discrete outputs, and up to 2 analogue inputs on most of these.
The switch button is connected to the input, and the motor is connected to the output. When we press the button, an electrical signal is sent to the PLC, which then delivers the signal to the CPU, which processes the data and sends the result to the output, which then converts the data to a raw signal.
This device is in charge of transforming analogue signals from external devices into digital signals that a computer can understand.
