A modern factory is a far cry from Henry Ford’s 1913 assembly line. That plant revolutionized manufacturing, but the introduction of industrial computing in the 1950s marked the beginning of electronics on the shop floor. Those initial innovations led straight to the factory of today, with advanced robotics, high-speed networks, real-time control, and thousands of intelligent nodes to monitor and report on every aspect of manufacturing operations.
1. A broad selection of functions is needed to cover the needs of an automated factory.
A typical factory-automation system contains three main levels (Fig. 1), also known as tiers or nodes, that drive real-time communications and control. Each of these levels requires its own set of optimized hardware and software solutions. The three levels are:
Field level: I/O modules, actuators, and drives operate the motors, valves, and other machines, plus gather data about machine status and process variables.
Control level: Programmable logic controllers (PLCs) or computer-numerical-control (CNC) machines collect information from, and issue commands to, field-level devices. PLCs have varying levels of capability based on their processing ability, number of connected nodes, cycle times, number of supported protocols, and more. Fanless operation is a must, so low power consumption is a key requirement.
Operator level: Human-machine interface (HMI) devices provide a visual interface to human operators and relay commands from them to the control level. Like PLCs, industrial HMIs come in varying levels of complexity, and must function within a factory environment that requires fieldbus connectivity and low-power fanless operation. As shown in Fig. 1, the HMI is increasingly built around a graphical user interface (GUI) with touchscreen capability.