In computing, input/output, or I/O, refers to the communication between an information processing system (such as a computer), and the outside world, possibly a human, or another information processing system. SCADA I/O modules are devices that are Input / Output to a SCADA. Inputs are Process parameters such as Temperature, Pressure, Flow rate, Humidity, Level etc called as Analog Inputs. Inputs from Flow switches, level switches, Pressure switches, Proximity switches, Limit switches, auxiliary contact of contactor etc are called Digital Inputs. Scan Electronic Systems provides variety of Analog and digital I/O modules with SCADA connectivity through RS232, RS485 and Ethernet with Modbus RTU and Modbus TCP protocols which are the most popularly used protocols in Industry.