What is PLC I/O ?
What is PLC I/O ? PLC I/O stands for Programmable Logic Controller Input and Output . These are the signals that a PLC receives (inputs) and sends (outputs) to control industrial equipment and processes. These signals allow the PLC to monitor (through inputs) and control (through outputs) the operation of a process or Instruments. In a PLC system, there are two main types of signals: Digital (Discrete) Signals: These are ON/OFF signals, such as switches, sensors, or relays. Example: Start/Stop push buttons, limit switches, contactors. Analog Signals: These are variable signals, representing a range of values (for example 0–10V or 4–20mA). Example: Temperature transmitters, pressure transmitters, speed controllers. Input Signals are received from field devices (like sensors, switches). Output Signals are sent from the PLC to control devices (like motors, valves, or lights). Types of I/O Signals PLC I/O signals are divided into two main categories based ...